1. Overview

The goal of this document is to provide comprehensive reference documentation for programmers writing tests, extension authors, and engine authors as well as build tool and IDE vendors.

1.1. What is JUnit 5?

Unlike previous versions of JUnit, JUnit 5 is composed of several different modules from three different sub-projects.

JUnit 5 = JUnit Platform + JUnit Jupiter + JUnit Vintage

The JUnit Platform serves as a foundation for launching testing frameworks on the JVM. It also defines the TestEngine API for developing a testing framework that runs on the platform. Furthermore, the platform provides a Console Launcher to launch the platform from the command line and build plugins for Gradle and Maven as well as a JUnit 4 based Runner for running any TestEngine on the platform.

JUnit Jupiter is the combination of the new programming model and extension model for writing tests and extensions in JUnit 5. The Jupiter sub-project provides a TestEngine for running Jupiter based tests on the platform.

JUnit Vintage provides a TestEngine for running JUnit 3 and JUnit 4 based tests on the platform.

1.2. Supported Java Versions

JUnit 5 requires Java 8 at runtime. However, you can still test code that has been compiled with previous versions of the JDK.

2. Installation

Artifacts for final releases and milestones are deployed to Maven Central.

Snapshot artifacts are deployed to Sonatype’s snapshots repository under /org/junit.

2.1. Dependency Metadata

2.1.1. JUnit Platform

  • Group ID: org.junit.platform

  • Version: 1.0.0-SNAPSHOT

  • Artifact IDs:

    junit-platform-commons

    Internal common library/utilities of JUnit. These utilities are intended solely for usage within the JUnit framework itself. Any usage by external parties is not supported. Use at your own risk!

    junit-platform-console

    Support for discovering and executing tests on the JUnit Platform from the console. See Console Launcher for details.

    junit-platform-console-standalone

    An executable JAR with all dependencies included is provided at Maven Central under the junit-platform-console-standalone directory. See Console Launcher for details.

    junit-platform-engine

    Public API for test engines. See Plugging in Your Own Test Engine for details.

    junit-platform-gradle-plugin

    Support for discovering and executing tests on the JUnit Platform using Gradle.

    junit-platform-launcher

    Public API for configuring and launching test plans — typically used by IDEs and build tools. See JUnit Platform Launcher API for details.

    junit-platform-runner

    Runner for executing tests and test suites on the JUnit Platform in a JUnit 4 environment. See Using JUnit 4 to Run the JUnit Platform for details.

    junit-platform-suite-api

    Annotations for configuring test suites on the JUnit Platform. Supported by the JUnitPlatform runner and possibly by third-party TestEngine implementations.

    junit-platform-surefire-provider

    Support for discovering and executing tests on the JUnit Platform using Maven Surefire.

2.1.2. JUnit Jupiter

  • Group ID: org.junit.jupiter

  • Version: 5.0.0-SNAPSHOT

  • Artifact IDs:

    junit-jupiter-api

    JUnit Jupiter API for writing tests and extensions.

    junit-jupiter-engine

    JUnit Jupiter test engine implementation, only required at runtime.

    junit-jupiter-params

    Support for parameterized tests in JUnit Jupiter.

    junit-jupiter-migrationsupport

    Migration support from JUnit 4 to JUnit Jupiter, only required for running selected JUnit 4 rules.

2.1.3. JUnit Vintage

  • Group ID: org.junit.vintage

  • Version: 4.12.0-SNAPSHOT

  • Artifact ID:

    junit-vintage-engine

    JUnit Vintage test engine implementation that allows to run vintage JUnit tests, i.e. tests written in the JUnit 3 or JUnit 4 style, on the new JUnit Platform.

2.2. Dependency Diagram

component diagram

2.3. JUnit Jupiter Sample Projects

The junit5-samples repository hosts a collection of sample projects based on JUnit Jupiter and JUnit Vintage. You’ll find the respective build.gradle and pom.xml in the projects below.

3. Writing Tests

A first test case
import static org.junit.jupiter.api.Assertions.assertEquals;

import org.junit.jupiter.api.Test;

class FirstJUnit5Tests {

    @Test
    void myFirstTest() {
        assertEquals(2, 1 + 1);
    }

}

3.1. Annotations

JUnit Jupiter supports the following annotations for configuring tests and extending the framework.

All core annotations are located in the org.junit.jupiter.api package in the junit-jupiter-api module.

Annotation Description

@Test

Denotes that a method is a test method. Unlike JUnit 4’s @Test annotation, this annotation does not declare any attributes, since test extensions in JUnit Jupiter operate based on their own dedicated annotations.

@RepeatedTest

Denotes that a method is a test template for a repeated test

@TestFactory

Denotes that a method is a test factory for dynamic tests

@DisplayName

Declares a custom display name for the test class or test method

@BeforeEach

Denotes that the annotated method should be executed before each @Test method in the current class; analogous to JUnit 4’s @Before. Such methods are inherited.

@AfterEach

Denotes that the annotated method should be executed after each @Test method in the current class; analogous to JUnit 4’s @After. Such methods are inherited.

@BeforeAll

Denotes that the annotated method should be executed before all @Test methods in the current class; analogous to JUnit 4’s @BeforeClass. Such methods must be static and are inherited.

@AfterAll

Denotes that the annotated method should be executed after all @Test methods in the current class; analogous to JUnit 4’s @AfterClass. Such methods must be static and are inherited.

@Nested

Denotes that the annotated class is a nested, non-static test class. Due to restrictions of the Java language, @BeforeAll and @AfterAll methods cannot be used in a @Nested test class.

@Tag

Used to declare tags for filtering tests, either at the class or method level; analogous to test groups in TestNG or Categories in JUnit 4

@Disabled

Used to disable a test class or test method; analogous to JUnit 4’s @Ignore

@ExtendWith

Used to register custom extensions

3.1.1. Meta-Annotations and Composed Annotations

JUnit Jupiter annotations can be used as meta-annotations. That means that you can define your own composed annotation that will automatically inherit the semantics of its meta-annotations.

For example, instead of copying and pasting @Tag("fast") throughout your code base (see Tagging and Filtering), you can create a custom composed annotation named @Fast as follows. @Fast can then be used as a drop-in replacement for @Tag("fast").

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

import org.junit.jupiter.api.Tag;

@Target({ ElementType.TYPE, ElementType.METHOD })
@Retention(RetentionPolicy.RUNTIME)
@Tag("fast")
public @interface Fast {
}

3.2. Standard Test Class

A standard test case
import static org.junit.jupiter.api.Assertions.fail;

import org.junit.jupiter.api.AfterAll;
import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.BeforeAll;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Disabled;
import org.junit.jupiter.api.Test;

class StandardTests {

    @BeforeAll
    static void initAll() {
    }

    @BeforeEach
    void init() {
    }

    @Test
    void succeedingTest() {
    }

    @Test
    void failingTest() {
        fail("a failing test");
    }

    @Test
    @Disabled("for demonstration purposes")
    void skippedTest() {
        // not executed
    }

    @AfterEach
    void tearDown() {
    }

    @AfterAll
    static void tearDownAll() {
    }

}
Neither test classes nor test methods need to be public.

3.3. Display Names

Test classes and test methods can declare custom display names — with spaces, special characters, and even emojis — that will be displayed by test runners and test reporting.

import org.junit.jupiter.api.DisplayName;
import org.junit.jupiter.api.Test;

@DisplayName("A special test case")
class DisplayNameDemo {

    @Test
    @DisplayName("Custom test name containing spaces")
    void testWithDisplayNameContainingSpaces() {
    }

    @Test
    @DisplayName("╯°□°)╯")
    void testWithDisplayNameContainingSpecialCharacters() {
    }

    @Test
    @DisplayName("😱")
    void testWithDisplayNameContainingEmoji() {
    }

}

3.4. Assertions

JUnit Jupiter comes with many of the assertion methods that JUnit 4 has and adds a few that lend themselves well to being used with Java 8 lambdas. All JUnit Jupiter assertions are static methods in the org.junit.jupiter.Assertions class.

import static java.time.Duration.ofMillis;
import static java.time.Duration.ofMinutes;
import static org.junit.jupiter.api.Assertions.assertAll;
import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertNotNull;
import static org.junit.jupiter.api.Assertions.assertThrows;
import static org.junit.jupiter.api.Assertions.assertTimeout;
import static org.junit.jupiter.api.Assertions.assertTimeoutPreemptively;
import static org.junit.jupiter.api.Assertions.assertTrue;

import org.junit.jupiter.api.Test;

class AssertionsDemo {

    @Test
    void standardAssertions() {
        assertEquals(2, 2);
        assertEquals(4, 4, "The optional assertion message is now the last parameter.");
        assertTrue(2 == 2, () -> "Assertion messages can be lazily evaluated -- "
                + "to avoid constructing complex messages unnecessarily.");
    }

    @Test
    void groupedAssertions() {
        // In a grouped assertion all assertions are executed, and any
        // failures will be reported together.
        assertAll("person",
            () -> assertEquals("John", person.getFirstName()),
            () -> assertEquals("Doe", person.getLastName())
        );
    }

    @Test
    void dependentAssertions() {
        // Within a code block, if an assertion fails the
        // subsequent code in the same block will be skipped.
        assertAll("properties",
            () -> {
                String firstName = person.getFirstName();
                assertNotNull(firstName);

                // Executed only if the previous assertion is valid.
                assertAll("first name",
                    () -> assertTrue(firstName.startsWith("J")),
                    () -> assertTrue(firstName.endsWith("n"))
                );
            },
            () -> {
                // Grouped assertion, so processed independently
                // of results of first name assertions.
                String lastName = person.getLastName();
                assertNotNull(lastName);

                // Executed only if the previous assertion is valid.
                assertAll("last name",
                    () -> assertTrue(lastName.startsWith("D")),
                    () -> assertTrue(lastName.endsWith("e"))
                );
            }
        );
    }

    @Test
    void exceptionTesting() {
        Throwable exception = assertThrows(IllegalArgumentException.class, () -> {
            throw new IllegalArgumentException("a message");
        });
        assertEquals("a message", exception.getMessage());
    }

    @Test
    void timeoutNotExceeded() {
        // The following assertion succeeds.
        assertTimeout(ofMinutes(2), () -> {
            // Perform task that takes less than 2 minutes.
        });
    }

    @Test
    void timeoutNotExceededWithResult() {
        // The following assertion succeeds, and returns the supplied object.
        String actualResult = assertTimeout(ofMinutes(2), () -> {
            return "a result";
        });
        assertEquals("a result", actualResult);
    }

    @Test
    void timeoutNotExceededWithMethod() {
        // The following assertion invokes a method reference and returns an object.
        String actualGreeting = assertTimeout(ofMinutes(2), AssertionsDemo::greeting);
        assertEquals("hello world!", actualGreeting);
    }

    @Test
    void timeoutExceeded() {
        // The following assertion fails with an error message similar to:
        // execution exceeded timeout of 10 ms by 91 ms
        assertTimeout(ofMillis(10), () -> {
            // Simulate task that takes more than 10 ms.
            Thread.sleep(100);
        });
    }

    @Test
    void timeoutExceededWithPreemptiveTermination() {
        // The following assertion fails with an error message similar to:
        // execution timed out after 10 ms
        assertTimeoutPreemptively(ofMillis(10), () -> {
            // Simulate task that takes more than 10 ms.
            Thread.sleep(100);
        });
    }

    private static String greeting() {
        return "hello world!";
    }

}

3.4.1. Third-party Assertion Libraries

Even though the assertion facilities provided by JUnit Jupiter are sufficient for many testing scenarios, there are times when more power and additional functionality such as matchers are desired or required. In such cases, the JUnit team recommends the use of third-party assertion libraries such as AssertJ, Hamcrest, Truth, etc. Developers are therefore free to use the assertion library of their choice.

For example, the combination of matchers and a fluent API can be used to make assertions more descriptive and readable. However, JUnit Jupiter’s org.junit.jupiter.Assertions class does not provide an assertThat() method like the one found in JUnit 4’s org.junit.Assert class which accepts a Hamcrest Matcher. Instead, developers are encouraged to use the built-in support for matchers provided by third-party assertion libraries.

The following example demonstrates how to use the assertThat() support from Hamcrest in a JUnit Jupiter test. As long as the Hamcrest library has been added to the classpath, you can statically import methods such as assertThat(), is(), and equalTo() and then use them in tests like in the assertWithHamcrestMatcher() method below.

import static org.hamcrest.CoreMatchers.equalTo;
import static org.hamcrest.CoreMatchers.is;
import static org.hamcrest.MatcherAssert.assertThat;

import org.junit.jupiter.api.Test;

class HamcrestAssertionDemo {

    @Test
    void assertWithHamcrestMatcher() {
        assertThat(2 + 1, is(equalTo(3)));
    }

}

Naturally, legacy tests based on the JUnit 4 programming model can continue using org.junit.Assert#assertThat.

3.5. Assumptions

JUnit Jupiter comes with a subset of the assumption methods that JUnit 4 provides and adds a few that lend themselves well to being used with Java 8 lambdas. All JUnit Jupiter assumptions are static methods in the org.junit.jupiter.Assumptions class.

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assumptions.assumeTrue;
import static org.junit.jupiter.api.Assumptions.assumingThat;

import org.junit.jupiter.api.Test;

class AssumptionsDemo {

    @Test
    void testOnlyOnCiServer() {
        assumeTrue("CI".equals(System.getenv("ENV")));
        // remainder of test
    }

    @Test
    void testOnlyOnDeveloperWorkstation() {
        assumeTrue("DEV".equals(System.getenv("ENV")),
            () -> "Aborting test: not on developer workstation");
        // remainder of test
    }

    @Test
    void testInAllEnvironments() {
        assumingThat("CI".equals(System.getenv("ENV")),
            () -> {
                // perform these assertions only on the CI server
                assertEquals(2, 2);
            });

        // perform these assertions in all environments
        assertEquals("a string", "a string");
    }

}

3.6. Disabling Tests

Here’s a disabled test case.

import org.junit.jupiter.api.Disabled;
import org.junit.jupiter.api.Test;

@Disabled
class DisabledClassDemo {
    @Test
    void testWillBeSkipped() {
    }
}

And here’s a test case with a disabled test method.

import org.junit.jupiter.api.Disabled;
import org.junit.jupiter.api.Test;

class DisabledTestsDemo {

    @Disabled
    @Test
    void testWillBeSkipped() {
    }

    @Test
    void testWillBeExecuted() {
    }
}

3.7. Tagging and Filtering

Test classes and methods can be tagged. Those tags can later be used to filter test discovery and execution.

import org.junit.jupiter.api.Tag;
import org.junit.jupiter.api.Test;

@Tag("fast")
@Tag("model")
class TaggingDemo {

    @Test
    @Tag("taxes")
    void testingTaxCalculation() {
    }

}

3.8. Nested Tests

Nested tests give the test writer more capabilities to express the relationship among several group of tests. Here’s an elaborate example.

Nested test suite for testing a stack
import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertFalse;
import static org.junit.jupiter.api.Assertions.assertThrows;
import static org.junit.jupiter.api.Assertions.assertTrue;

import java.util.EmptyStackException;
import java.util.Stack;

import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.DisplayName;
import org.junit.jupiter.api.Nested;
import org.junit.jupiter.api.Test;

@DisplayName("A stack")
class TestingAStackDemo {

    Stack<Object> stack;

    @Test
    @DisplayName("is instantiated with new Stack()")
    void isInstantiatedWithNew() {
        new Stack<>();
    }

    @Nested
    @DisplayName("when new")
    class WhenNew {

        @BeforeEach
        void createNewStack() {
            stack = new Stack<>();
        }

        @Test
        @DisplayName("is empty")
        void isEmpty() {
            assertTrue(stack.isEmpty());
        }

        @Test
        @DisplayName("throws EmptyStackException when popped")
        void throwsExceptionWhenPopped() {
            assertThrows(EmptyStackException.class, () -> stack.pop());
        }

        @Test
        @DisplayName("throws EmptyStackException when peeked")
        void throwsExceptionWhenPeeked() {
            assertThrows(EmptyStackException.class, () -> stack.peek());
        }

        @Nested
        @DisplayName("after pushing an element")
        class AfterPushing {

            String anElement = "an element";

            @BeforeEach
            void pushAnElement() {
                stack.push(anElement);
            }

            @Test
            @DisplayName("it is no longer empty")
            void isNotEmpty() {
                assertFalse(stack.isEmpty());
            }

            @Test
            @DisplayName("returns the element when popped and is empty")
            void returnElementWhenPopped() {
                assertEquals(anElement, stack.pop());
                assertTrue(stack.isEmpty());
            }

            @Test
            @DisplayName("returns the element when peeked but remains not empty")
            void returnElementWhenPeeked() {
                assertEquals(anElement, stack.peek());
                assertFalse(stack.isEmpty());
            }
        }
    }
}
Only non-static nested classes (i.e. inner classes) can serve as @Nested tests. Nesting can be arbitrarily deep, and those inner classes are considered to be full members of the test class family with one exception: @BeforeAll and @AfterAll do not work, because Java does not allow static members in inner classes.

3.9. Dependency Injection for Constructors and Methods

In all prior JUnit versions, test constructors or methods were not allowed to have parameters (at least not with the standard Runner implementations). As one of the major changes in JUnit Jupiter, both test constructors and methods are now permitted to have parameters. This allows for greater flexibility and enables Dependency Injection for constructors and methods.

ParameterResolver defines the API for test extensions that wish to dynamically resolve parameters at runtime. If a test constructor or a @Test, @TestFactory, @BeforeEach, @AfterEach, @BeforeAll, or @AfterAll method accepts a parameter, the parameter must be resolved at runtime by a registered ParameterResolver.

There are currently three built-in resolvers that are registered automatically.

  • TestInfoParameterResolver: if a method parameter is of type TestInfo, the TestInfoParameterResolver will supply an instance of TestInfo corresponding to the current test as the value for the parameter. The TestInfo can then be used to retrieve information about the current test such as the test’s display name, the test class, the test method, or associated tags. The display name is either a technical name, such as the name of the test class or test method, or a custom name configured via @DisplayName.

    TestInfo acts as a drop-in replacement for the TestName rule from JUnit 4. The following demonstrates how to have TestInfo injected into a test constructor, @BeforeEach method, and @Test method.

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertTrue;

import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.DisplayName;
import org.junit.jupiter.api.Tag;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.TestInfo;

@DisplayName("TestInfo Demo")
class TestInfoDemo {

    TestInfoDemo(TestInfo testInfo) {
        assertEquals("TestInfo Demo", testInfo.getDisplayName());
    }

    @BeforeEach
    void init(TestInfo testInfo) {
        String displayName = testInfo.getDisplayName();
        assertTrue(displayName.equals("TEST 1") || displayName.equals("test2()"));
    }

    @Test
    @DisplayName("TEST 1")
    @Tag("my tag")
    void test1(TestInfo testInfo) {
        assertEquals("TEST 1", testInfo.getDisplayName());
        assertTrue(testInfo.getTags().contains("my tag"));
    }

    @Test
    void test2() {
    }

}
  • RepetitionInfoParameterResolver: if a method parameter in a @RepeatedTest, @BeforeEach, or @AfterEach method is of type RepetitionInfo, the RepetitionInfoParameterResolver will supply an instance of RepetitionInfo. RepetitionInfo can then be used to retrieve information about the current repetition and the total number of repetitions for the corresponding @RepeatedTest. Note, however, that RepetitionInfoParameterResolver is not registered outside the context of a @RepeatedTest. See Repeated Test Examples.

  • TestReporterParameterResolver: if a method parameter is of type TestReporter, the TestReporterParameterResolver will supply an instance of TestReporter. The TestReporter can be used to publish additional data about the current test run. The data can be consumed through TestExecutionListener.reportingEntryPublished() and thus be viewed by IDEs or included in reports.

    In JUnit Jupiter you should use TestReporter where you used to print information to stdout or stderr in JUnit 4. Using @RunWith(JUnitPlatform.class) will even output all reported entries to stdout.

import java.util.HashMap;

import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.TestReporter;

class TestReporterDemo {

    @Test
    void reportSingleValue(TestReporter testReporter) {
        testReporter.publishEntry("a key", "a value");
    }

    @Test
    void reportSeveralValues(TestReporter testReporter) {
        HashMap<String, String> values = new HashMap<>();
        values.put("user name", "dk38");
        values.put("award year", "1974");

        testReporter.publishEntry(values);
    }

}
Other parameter resolvers must be explicitly enabled by registering appropriate extensions via @ExtendWith.

Check out the MockitoExtension for an example of a custom ParameterResolver. While not intended to be production-ready, it demonstrates the simplicity and expressiveness of both the extension model and the parameter resolution process. MyMockitoTest demonstrates how to inject Mockito mocks into @BeforeEach and @Test methods.

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.mockito.Mockito.when;

import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;
import org.mockito.Mock;
import com.example.Person;
import com.example.mockito.MockitoExtension;

@ExtendWith(MockitoExtension.class)
class MyMockitoTest {

    @BeforeEach
    void init(@Mock Person person) {
        when(person.getName()).thenReturn("Dilbert");
    }

    @Test
    void simpleTestWithInjectedMock(@Mock Person person) {
        assertEquals("Dilbert", person.getName());
    }

}

3.10. Test Interfaces and Default Methods

JUnit Jupiter allows @Test, @TestFactory, @BeforeEach, and @AfterEach to be declared on interface default methods. In addition, @BeforeAll and @AfterAll can be declared on static methods in a test interface, while @ExtendWith and @Tag can be declared on test interfaces to configure extensions and tags. Here are some examples.

public interface TestLifecycleLogger {

    static final Logger LOG = Logger.getLogger(TestLifecycleLogger.class.getName());

    @BeforeAll
    static void beforeAllTests() {
        LOG.info("beforeAllTests");
    }

    @AfterAll
    static void afterAllTests() {
        LOG.info("afterAllTests");
    }

    @BeforeEach
    default void beforeEachTest(TestInfo testInfo) {
        LOG.info(() -> String.format("About to execute [%s]",
            testInfo.getDisplayName()));
    }

    @AfterEach
    default void afterEachTest(TestInfo testInfo) {
        LOG.info(() -> String.format("Finished executing [%s]",
            testInfo.getDisplayName()));
    }

}
interface TestInterfaceDynamicTestsDemo {

    @TestFactory
    default Collection<DynamicTest> dynamicTestsFromCollection() {
        return Arrays.asList(
            dynamicTest("1st dynamic test in test interface", () -> assertTrue(true)),
            dynamicTest("2nd dynamic test in test interface", () -> assertEquals(4, 2 * 2))
        );
    }

}

@ExtendWith and @Tag can be declared on a test interface so that classes that implement it automatically inherit its tags and extensions. See Before and After Test Execution Callbacks for the source code of the TimingExtension.

@Tag("timed")
@ExtendWith(TimingExtension.class)
public interface TimeExecutionLogger {
}

In your test class you can then implement these test interfaces to have them applied.

class TestInterfaceDemo implements TestLifecycleLogger, TimeExecutionLogger, TestInterfaceDynamicTestsDemo {

    @Test
    void isEqualValue() {
        assertEquals(1, 1, "is always equal");
    }

}

Running the TestInterfaceDemo results in output similar to the following:

:junitPlatformTest
18:28:13.967 [main] INFO  example.testinterface.TestLifecycleLogger - beforeAllTests
18:28:13.982 [main] INFO  example.testinterface.TestLifecycleLogger - About to execute [dynamicTestsFromCollection()]
18:28:14.000 [main] INFO  example.testinterface.TimingExtension - Method [dynamicTestsFromCollection] took 13 ms.
18:28:14.004 [main] INFO  example.testinterface.TestLifecycleLogger - Finished executing [dynamicTestsFromCollection()]
18:28:14.007 [main] INFO  example.testinterface.TestLifecycleLogger - About to execute [isEqualValue()]
18:28:14.008 [main] INFO  example.testinterface.TimingExtension - Method [isEqualValue] took 1 ms.
18:28:14.009 [main] INFO  example.testinterface.TestLifecycleLogger - Finished executing [isEqualValue()]
18:28:14.011 [main] INFO  example.testinterface.TestLifecycleLogger - afterAllTests

Test run finished after 190 ms
[         3 containers found      ]
[         0 containers skipped    ]
[         3 containers started    ]
[         0 containers aborted    ]
[         3 containers successful ]
[         0 containers failed     ]
[         3 tests found           ]
[         0 tests skipped         ]
[         3 tests started         ]
[         0 tests aborted         ]
[         3 tests successful      ]
[         0 tests failed          ]

BUILD SUCCESSFUL

Another possible application of this feature is to write tests for interface contracts. For example, you can write tests for how implementations of Object.equals or Comparable.compareTo should behave as follows.

public interface Testable<T> {

    T createValue();

}
public interface EqualsContract<T> extends Testable<T> {

    T createNotEqualValue();

    @Test
    default void valueEqualsItself() {
        T value = createValue();
        assertEquals(value, value);
    }

    @Test
    default void valueDoesNotEqualNull() {
        T value = createValue();
        assertFalse(value.equals(null));
    }

    @Test
    default void valueDoesNotEqualDifferentValue() {
        T value = createValue();
        T differentValue = createNotEqualValue();
        assertNotEquals(value, differentValue);
        assertNotEquals(differentValue, value);
    }

}
public interface ComparableContract<T extends Comparable<T>> extends Testable<T> {

    T createSmallerValue();

    @Test
    default void returnsZeroWhenComparedToItself() {
        T value = createValue();
        assertEquals(0, value.compareTo(value));
    }

    @Test
    default void returnsPositiveNumberComparedToSmallerValue() {
        T value = createValue();
        T smallerValue = createSmallerValue();
        assertTrue(value.compareTo(smallerValue) > 0);
    }

    @Test
    default void returnsNegativeNumberComparedToSmallerValue() {
        T value = createValue();
        T smallerValue = createSmallerValue();
        assertTrue(smallerValue.compareTo(value) < 0);
    }

}

In your test class you can then implement both contract interfaces thereby inheriting the corresponding tests. Of course you’ll have to implement the abstract methods.

class StringTests implements ComparableContract<String>, EqualsContract<String> {

    @Override
    public String createValue() {
        return "foo";
    }

    @Override
    public String createSmallerValue() {
        return "bar"; // 'b' < 'f' in "foo"
    }

    @Override
    public String createNotEqualValue() {
        return "baz";
    }

}

The above tests are merely meant as examples and therefore not complete.

3.11. Repeated Tests

JUnit Jupiter provides the ability to repeat a test a specified number of times simply by annotating a method with @RepeatedTest and specifying the total number of repetitions desired. Each invocation of a repeated test behaves like the execution of a regular @Test method with full support for the same lifecycle callbacks and extensions.

The following example demonstrates how to declare a test named repeatedTest() that will be automatically repeated 10 times.

@RepeatedTest(10)
void repeatedTest() {
    // ...
}

In addition to specifying the number of repetitions, a custom display name can be configured for each repetition via the name attribute of the @RepeatedTest annotation. Furthermore, the display name can be a pattern composed of a combination of static text and dynamic placeholders. The following placeholders are currently supported.

  • {displayName}: display name of the @RepeatedTest method

  • {currentRepetition}: the current repetition count

  • {totalRepetitions}: the total number of repetitions

The default display name for a given repetition is generated based on the following pattern: "repetition {currentRepetition} of {totalRepetitions}". Thus, the display names for individual repetitions of the previous repeatedTest() example would be: repetition 1 of 10, repetition 2 of 10, etc. If you would like the display name of the @RepeatedTest method included in the name of each repetition, you can define your own custom pattern or use the predefined RepeatedTest.LONG_DISPLAY_NAME pattern. The latter is equal to "{displayName} :: repetition {currentRepetition} of {totalRepetitions}" which results in display names for individual repetitions like repeatedTest() :: repetition 1 of 10, repeatedTest() :: repetition 2 of 10, etc.

In order to retrieve information about the current repetition and the total number of repetitions programmatically, a developer can choose to have an instance of RepetitionInfo injected into a @RepeatedTest, @BeforeEach, or @AfterEach method.

3.11.1. Repeated Test Examples

The RepeatedTestsDemo class at the end of this section demonstrates several examples of repeated tests.

The repeatedTest() method is identical to example from the previous section; whereas, repeatedTestWithRepetitionInfo() demonstrates how to have an instance of RepetitionInfo injected into a test to access the total number of repetitions for the current repeated test.

The next two methods demonstrate how to include a custom @DisplayName for the @RepeatedTest method in the display name of each repetition. customDisplayName() combines a custom display name with a custom pattern and then uses TestInfo to verify the format of the generated display name. Repeat! is the {displayName} which comes from the @DisplayName declaration, and 1/1 comes from {currentRepetition}/{totalRepetitions}. In contrast, customDisplayNameWithLongPattern() uses the aforementioned predefined RepeatedTest.LONG_DISPLAY_NAME pattern.

repeatedTestInGerman() demonstrates the ability to translate display names of repeated tests into foreign languages — in this case German, resulting in names for individual repetitions such as: Wiederholung 1 von 5, Wiederholung 2 von 5, etc.

Since the beforeEach() method is annotated with @BeforeEach it will get executed before each repetition of each repeated test. By having the TestInfo and RepetitionInfo injected into the method, we see that it’s possible to obtain information about the currently executing repeated test. Executing RepeatedTestsDemo with the INFO log level enabled results in the following output.

INFO: About to execute repetition 1 of 10 for repeatedTest
INFO: About to execute repetition 2 of 10 for repeatedTest
INFO: About to execute repetition 3 of 10 for repeatedTest
INFO: About to execute repetition 4 of 10 for repeatedTest
INFO: About to execute repetition 5 of 10 for repeatedTest
INFO: About to execute repetition 6 of 10 for repeatedTest
INFO: About to execute repetition 7 of 10 for repeatedTest
INFO: About to execute repetition 8 of 10 for repeatedTest
INFO: About to execute repetition 9 of 10 for repeatedTest
INFO: About to execute repetition 10 of 10 for repeatedTest
INFO: About to execute repetition 1 of 5 for repeatedTestWithRepetitionInfo
INFO: About to execute repetition 2 of 5 for repeatedTestWithRepetitionInfo
INFO: About to execute repetition 3 of 5 for repeatedTestWithRepetitionInfo
INFO: About to execute repetition 4 of 5 for repeatedTestWithRepetitionInfo
INFO: About to execute repetition 5 of 5 for repeatedTestWithRepetitionInfo
INFO: About to execute repetition 1 of 1 for customDisplayName
INFO: About to execute repetition 1 of 1 for customDisplayNameWithLongPattern
INFO: About to execute repetition 1 of 5 for repeatedTestInGerman
INFO: About to execute repetition 2 of 5 for repeatedTestInGerman
INFO: About to execute repetition 3 of 5 for repeatedTestInGerman
INFO: About to execute repetition 4 of 5 for repeatedTestInGerman
INFO: About to execute repetition 5 of 5 for repeatedTestInGerman
import static org.junit.jupiter.api.Assertions.assertEquals;

import java.util.logging.Logger;

import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.DisplayName;
import org.junit.jupiter.api.RepeatedTest;
import org.junit.jupiter.api.RepetitionInfo;
import org.junit.jupiter.api.TestInfo;

class RepeatedTestsDemo {

    private Logger logger = // ...

    @BeforeEach
    void beforeEach(TestInfo testInfo, RepetitionInfo repetitionInfo) {
        int currentRepetition = repetitionInfo.getCurrentRepetition();
        int totalRepetitions = repetitionInfo.getTotalRepetitions();
        String methodName = testInfo.getTestMethod().get().getName();
        logger.info(String.format("About to execute repetition %d of %d for %s", //
            currentRepetition, totalRepetitions, methodName));
    }

    @RepeatedTest(10)
    void repeatedTest() {
        // ...
    }

    @RepeatedTest(5)
    void repeatedTestWithRepetitionInfo(RepetitionInfo repetitionInfo) {
        assertEquals(5, repetitionInfo.getTotalRepetitions());
    }

    @RepeatedTest(value = 1, name = "{displayName} {currentRepetition}/{totalRepetitions}")
    @DisplayName("Repeat!")
    void customDisplayName(TestInfo testInfo) {
        assertEquals(testInfo.getDisplayName(), "Repeat! 1/1");
    }

    @RepeatedTest(value = 1, name = RepeatedTest.LONG_DISPLAY_NAME)
    @DisplayName("Details...")
    void customDisplayNameWithLongPattern(TestInfo testInfo) {
        assertEquals(testInfo.getDisplayName(), "Details... :: repetition 1 of 1");
    }

    @RepeatedTest(value = 5, name = "Wiederholung {currentRepetition} von {totalRepetitions}")
    void repeatedTestInGerman() {
        // ...
    }

}

When using the ConsoleLauncher or the junitPlatformTest Gradle plugin with the unicode theme enabled, execution of RepeatedTestsDemo results in the following output to the console.

├─ RepeatedTestsDemo ✔
│  ├─ repeatedTest() ✔
│  │  ├─ repetition 1 of 10 ✔
│  │  ├─ repetition 2 of 10 ✔
│  │  ├─ repetition 3 of 10 ✔
│  │  ├─ repetition 4 of 10 ✔
│  │  ├─ repetition 5 of 10 ✔
│  │  ├─ repetition 6 of 10 ✔
│  │  ├─ repetition 7 of 10 ✔
│  │  ├─ repetition 8 of 10 ✔
│  │  ├─ repetition 9 of 10 ✔
│  │  └─ repetition 10 of 10 ✔
│  ├─ repeatedTestWithRepetitionInfo(RepetitionInfo) ✔
│  │  ├─ repetition 1 of 5 ✔
│  │  ├─ repetition 2 of 5 ✔
│  │  ├─ repetition 3 of 5 ✔
│  │  ├─ repetition 4 of 5 ✔
│  │  └─ repetition 5 of 5 ✔
│  ├─ Repeat! ✔
│  │  └─ Repeat! 1/1 ✔
│  ├─ Details... ✔
│  │  └─ Details... :: repetition 1 of 1 ✔
│  └─ repeatedTestInGerman() ✔
│     ├─ Wiederholung 1 von 5 ✔
│     ├─ Wiederholung 2 von 5 ✔
│     ├─ Wiederholung 3 von 5 ✔
│     ├─ Wiederholung 4 von 5 ✔
│     └─ Wiederholung 5 von 5 ✔

3.12. Parameterized Tests

Parameterized tests make it possible to run a test multiple times with different arguments. They are declared just like regular @Test methods but use the @ParameterizedTest annotation instead. In addition, you must declare at least one source that will provide the arguments for each invocation.

@ParameterizedTest
@ValueSource(strings = { "Hello", "World" })
void testWithStringParameter(String argument) {
    assertNotNull(argument);
}

This parameterized test uses the @ValueSource annotation to specify a String array as the source of arguments. When executing this method, each invocation will be reported separately. For instance, the ConsoleLauncher will print output similar to the following.

testWithStringParameter(String) ✔
├─ [1] Hello ✔
└─ [2] World ✔

3.12.1. Required Setup

In order to use parameterized tests you need to add a dependency on the junit-jupiter-params artifact. Please refer to Dependency Metadata for details.

3.12.2. Sources of Arguments

Out of the box, JUnit Jupiter provides quite a few source annotations. Each of the following subsections provides a brief overview and an example for each of them. Please refer to the JavaDoc in the org.junit.jupiter.params.provider package for additional information.

@ValueSource

@ValueSource is one of the simplest possible sources. It lets you specify an array of literals of primitive types (either String, int, long, or double) and can only be used for providing a single parameter per invocation.

@ParameterizedTest
@ValueSource(ints = { 1, 2, 3 })
void testWithValueSource(int argument) {
    assertNotNull(argument);
}
@EnumSource

@EnumSource provides a convenient way to use Enum constants. The annotation provides an optional names parameter that lets you specify which constants shall be used. If omitted, all constants will be used like in the following example.

@ParameterizedTest
@EnumSource(TimeUnit.class)
void testWithEnumSource(TimeUnit timeUnit) {
    assertNotNull(timeUnit);
}
@ParameterizedTest
@EnumSource(value = TimeUnit.class, names = { "DAYS", "HOURS" })
void testWithEnumSourceInclude(TimeUnit timeUnit) {
    assertTrue(EnumSet.of(TimeUnit.DAYS, TimeUnit.HOURS).contains(timeUnit));
}

The @EnumSource annotation also provides an optional mode parameter that enables fine-grained control over which constants are passed to the test method. For example, you can exclude names from the enum constant pool or specify regular expressions as in the following examples.

@ParameterizedTest
@EnumSource(value = TimeUnit.class, mode = EXCLUDE, names = { "DAYS", "HOURS" })
void testWithEnumSourceExclude(TimeUnit timeUnit) {
    assertFalse(EnumSet.of(TimeUnit.DAYS, TimeUnit.HOURS).contains(timeUnit));
    assertTrue(timeUnit.name().length() > 5);
}
@ParameterizedTest
@EnumSource(value = TimeUnit.class, mode = MATCH_ALL, names = "^(M|N).+SECONDS$")
void testWithEnumSourceRegex(TimeUnit timeUnit) {
    String name = timeUnit.name();
    assertTrue(name.startsWith("M") || name.startsWith("N"));
    assertTrue(name.endsWith("SECONDS"));
}
@MethodSource

@MethodSource allows you to refer to one or multiple methods of the test class. Each method must return a Stream, an Iterable, an Iterator, or an array of arguments. In addition, each method must be static and must not accept any arguments.

If you only need a single parameter, you can return instances of the parameter type directly as demonstrated by the following example.

@ParameterizedTest
@MethodSource("stringProvider")
void testWithSimpleMethodSource(String argument) {
    assertNotNull(argument);
}

static Stream<String> stringProvider() {
    return Stream.of("foo", "bar");
}

Streams for primitive types (DoubleStream, IntStream, and LongStream) are also supported.

@ParameterizedTest
@MethodSource("range")
void testWithRangeMethodSource(int argument) {
    assertNotEquals(9, argument);
}

static IntStream range() {
    return IntStream.range(0, 20).skip(10);
}

In case you need multiple parameters, you need to return an Arguments instances as shown below. Note that Arguments.of(Object…​) is a static factory method defined in the interface itself.

@ParameterizedTest
@MethodSource("stringAndIntProvider")
void testWithMultiArgMethodSource(String first, int second) {
    assertNotNull(first);
    assertNotEquals(0, second);
}

static Stream<Arguments> stringAndIntProvider() {
    return Stream.of(Arguments.of("foo", 1), Arguments.of("bar", 2));
}
@CsvSource

@CsvSource allows you to express argument lists as comma-separated values (i.e., String literals).

@ParameterizedTest
@CsvSource({ "foo, 1", "bar, 2", "'baz, qux', 3" })
void testWithCsvSource(String first, int second) {
    assertNotNull(first);
    assertNotEquals(0, second);
}
@CsvFileSource

@CsvFileSource lets you use CSV files from the classpath. Each line from a CSV file results in one invocation of the parameterized test.

@ParameterizedTest
@CsvFileSource(resources = "/two-column.csv")
void testWithCsvFileSource(String first, int second) {
    assertNotNull(first);
    assertNotEquals(0, second);
}
two-column.csv
foo, 1
bar, 2
"baz, qux", 3
@ArgumentsSource

@ArgumentsSource can be used to specify a custom, reusable ArgumentsProvider.

@ParameterizedTest
@ArgumentsSource(MyArgumentsProvider.class)
void testWithArgumentsSource(String argument) {
    assertNotNull(argument);
}

static class MyArgumentsProvider implements ArgumentsProvider {

    @Override
    public Stream<? extends Arguments> provideArguments(ContainerExtensionContext context) {
        return Stream.of("foo", "bar").map(Arguments::of);
    }
}

3.12.3. Argument Conversion

Implicit Conversion

To support use cases like @CsvSource, JUnit Jupiter provides a number of built-in implicit type converters. The conversion process depends on the declared type of each method parameter.

For example, if a @ParameterizedTest declares a parameter of type TimeUnit and the actual type supplied by the declared source is a String, the string will automatically be converted into the corresponding TimeUnit enum constant.

@ParameterizedTest
@ValueSource(strings = "SECONDS")
void testWithImplicitArgumentConversion(TimeUnit argument) {
    assertNotNull(argument.name());
}

String instances are currently implicitly converted to the following target types.

Target Type Example

boolean/Boolean

"true"true

byte/Byte

"1"(byte) 1

char/Character

"o"'o'

short/Short

"1"(short) 1

int/Integer

"1"1

long/Long

"1"1L

float/Float

"1.0"1.0f

double/Double

"1.0"1.0d

Enum subclass

"SECONDS"TimeUnit.SECONDS

java.time.Instant

"1970-01-01T00:00:00Z"Instant.ofEpochMilli(0)

java.time.LocalDate

"2017-03-14"LocalDate.of(2017, 3, 14)

java.time.LocalDateTime

"2017-03-14T12:34:56.789"LocalDateTime.of(2017, 3, 14, 12, 34, 56, 789_000_000)

java.time.LocalTime

"12:34:56.789"LocalTime.of(12, 34, 56, 789_000_000)

java.time.OffsetDateTime

"2017-03-14T12:34:56.789Z"OffsetDateTime.of(2017, 3, 14, 12, 34, 56, 789_000_000, ZoneOffset.UTC)

java.time.OffsetTime

"12:34:56.789Z"OffsetTime.of(12, 34, 56, 789_000_000, ZoneOffset.UTC)

java.time.Year

"2017"Year.of(2017)

java.time.YearMonth

"2017-03"YearMonth.of(2017, 3)

java.time.ZonedDateTime

"2017-03-14T12:34:56.789Z"ZonedDateTime.of(2017, 3, 14, 12, 34, 56, 789_000_000, ZoneOffset.UTC)

Explicit Conversion

Instead of using implicit argument conversion you may explicitly specify an ArgumentConverter to use for a certain parameter using the @ConvertWith annotation like in the following example.

@ParameterizedTest
@EnumSource(TimeUnit.class)
void testWithExplicitArgumentConversion(@ConvertWith(ToStringArgumentConverter.class) String argument) {
    assertNotNull(TimeUnit.valueOf(argument));
}

static class ToStringArgumentConverter extends SimpleArgumentConverter {

    @Override
    protected Object convert(Object source, Class<?> targetType) {
        assertEquals(String.class, targetType, "Can only convert to String");
        return String.valueOf(source);
    }
}

Explicit argument converters are meant to be implemented by test authors. Thus, junit-jupiter-params only provides a single explicit argument converter that may also serve as a reference implementation: JavaTimeArgumentConverter. It is used via the composed annotation JavaTimeConversionPattern.

@ParameterizedTest
@ValueSource(strings = { "01.01.2017", "31.12.2017" })
void testWithExplicitJavaTimeConverter(@JavaTimeConversionPattern("dd.MM.yyyy") LocalDate argument) {
    assertEquals(2017, argument.getYear());
}

3.12.4. Customizing Display Names

By default, the display name of a parameterized test invocation contains the invocation index and the String representation of all arguments for that specific invocation. However, you can customize invocation display names via the name attribute of the @ParameterizedTest annotation like in the following example.

@DisplayName("Display name of container")
@ParameterizedTest(name = "{index} ==> first=''{0}'', second={1}")
@CsvSource({ "foo, 1", "bar, 2", "'baz, qux', 3" })
void testWithCustomDisplayNames(String first, int second) {
}

When executing the above method using the ConsoleLauncher you will see output similar to the following.

Display name of container ✔
├─ 1 ==> first='foo', second=1 ✔
├─ 2 ==> first='bar', second=2 ✔
└─ 3 ==> first='baz, qux', second=3 ✔

The following placeholders are supported within custom display names.

Placeholder Description

{index}

the current invocation index (1-based)

{arguments}

the complete, comma-separated arguments list

{0}, {1}, …​

an individual argument

3.12.5. Lifecycle and Interoperability

Each invocation of a parameterized test has the same lifecycle as a regular @Test method. For example, @BeforeEach methods will be executed before each invocation. Similar to Dynamic Tests, invocations will appear one by one in the test tree of an IDE. You may at will mix regular @Test methods and @ParameterizedTest methods within the same test class.

You may use ParameterResolver extensions with @ParameterizedTest methods. However, method parameters that are resolved by argument sources need to come first in the argument list. Since a test class may contain regular tests as well as parameterized tests with different parameter lists, values from argument sources are not resolved for lifecycle methods (e.g. @BeforeEach) and test class constructors.

@BeforeEach
void beforeEach(TestInfo testInfo) {
    // ...
}

@ParameterizedTest
@ValueSource(strings = "foo")
void testWithRegularParameterResolver(String argument, TestReporter testReporter) {
    testReporter.publishEntry("argument", argument);
}

@AfterEach
void afterEach(TestInfo testInfo) {
    // ...
}

3.13. Dynamic Tests

The standard @Test annotation in JUnit Jupiter described in Annotations is very similar to the @Test annotation in JUnit 4. Both describe methods that implement test cases. These test cases are static in the sense that they are fully specified at compile time, and their behavior cannot be changed by anything happening at runtime. Assumptions provide a basic form of dynamic behavior but are intentionally rather limited in their expressiveness.

In addition to these standard tests a completely new kind of test programming model has been introduced in JUnit Jupiter. This new kind of test is a dynamic test which is generated at runtime by a factory method that is annotated with @TestFactory.

In contrast to @Test methods, a @TestFactory method is not itself a test case but rather a factory for test cases. Thus, a dynamic test is the product of a factory. Technically speaking, a @TestFactory method must return a Stream, Collection, Iterable, or Iterator of DynamicNode instances. Instantiable subclasses of DynamicNode are DynamicContainer and DynamicTest. DynamicContainer instances are composed of a display name and a list of dynamic child nodes, enabling the creation of arbitrarily nested hierarchies of dynamic nodes. DynamicTest instances will then be executed lazily, enabling dynamic and even non-deterministic generation of test cases.

Any Stream returned by a @TestFactory will be properly closed by calling stream.close(), making it safe to use a resource such as Files.lines().

As with @Test methods, @TestFactory methods must not be private or static and may optionally declare parameters to be resolved by ParameterResolvers.

A DynamicTest is a test case generated at runtime. It is composed of a display name and an Executable. Executable is a @FunctionalInterface which means that the implementations of dynamic tests can be provided as lambda expressions or method references.

Dynamic Test Lifecycle
The execution lifecycle of a dynamic test is quite different than it is for a standard @Test case. Specifically, there are no lifecycle callbacks for individual dynamic tests. This means that @BeforeEach and @AfterEach methods and their corresponding extension callbacks are executed for the @TestFactory method, not for each dynamic test. In other words, if you access fields from the test instance within a lambda expression for a dynamic test, those fields will not be reset by callback methods or extensions between the execution of individual dynamic tests generated by the same @TestFactory method.

As of JUnit Jupiter 5.0.0-SNAPSHOT, dynamic tests must always be created by factory methods; however, this might be complemented by a registration facility in a later release.

3.13.1. Dynamic Test Examples

The following DynamicTestsDemo class demonstrates several examples of test factories and dynamic tests.

The first method returns an invalid return type. Since an invalid return type cannot be detected at compile time, a JUnitException is thrown when it is detected at runtime.

The next five methods are very simple examples that demonstrate the generation of a Collection, Iterable, Iterator, or Stream of DynamicTest instances. Most of these examples do not really exhibit dynamic behavior but merely demonstrate the supported return types in principle. However, dynamicTestsFromStream() and dynamicTestsFromIntStream() demonstrate how easy it is to generate dynamic tests for a given set of strings or a range of input numbers.

The next method is truly dynamic in nature. generateRandomNumberOfTests() implements an Iterator that generates random numbers, a display name generator, and a test executor and then provides all three to DynamicTest.stream(). Although the non-deterministic behavior of generateRandomNumberOfTests() is of course in conflict with test repeatability and should thus be used with care, it serves to demonstrate the expressiveness and power of dynamic tests.

The last method generates a nested hierarchy of dynamic tests utilizing DynamicContainer.

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertFalse;
import static org.junit.jupiter.api.Assertions.assertNotNull;
import static org.junit.jupiter.api.Assertions.assertTrue;
import static org.junit.jupiter.api.DynamicContainer.dynamicContainer;
import static org.junit.jupiter.api.DynamicTest.dynamicTest;

import java.util.Arrays;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.Random;
import java.util.function.Function;
import java.util.stream.IntStream;
import java.util.stream.Stream;

import org.junit.jupiter.api.DynamicNode;
import org.junit.jupiter.api.DynamicTest;
import org.junit.jupiter.api.Tag;
import org.junit.jupiter.api.TestFactory;
import org.junit.jupiter.api.function.ThrowingConsumer;

class DynamicTestsDemo {

    // This will result in a JUnitException!
    @TestFactory
    List<String> dynamicTestsWithInvalidReturnType() {
        return Arrays.asList("Hello");
    }

    @TestFactory
    Collection<DynamicTest> dynamicTestsFromCollection() {
        return Arrays.asList(
            dynamicTest("1st dynamic test", () -> assertTrue(true)),
            dynamicTest("2nd dynamic test", () -> assertEquals(4, 2 * 2))
        );
    }

    @TestFactory
    Iterable<DynamicTest> dynamicTestsFromIterable() {
        return Arrays.asList(
            dynamicTest("3rd dynamic test", () -> assertTrue(true)),
            dynamicTest("4th dynamic test", () -> assertEquals(4, 2 * 2))
        );
    }

    @TestFactory
    Iterator<DynamicTest> dynamicTestsFromIterator() {
        return Arrays.asList(
            dynamicTest("5th dynamic test", () -> assertTrue(true)),
            dynamicTest("6th dynamic test", () -> assertEquals(4, 2 * 2))
        ).iterator();
    }

    @TestFactory
    Stream<DynamicTest> dynamicTestsFromStream() {
        return Stream.of("A", "B", "C")
            .map(str -> dynamicTest("test" + str, () -> { /* ... */ }));
    }

    @TestFactory
    Stream<DynamicTest> dynamicTestsFromIntStream() {
        // Generates tests for the first 10 even integers.
        return IntStream.iterate(0, n -> n + 2).limit(10)
            .mapToObj(n -> dynamicTest("test" + n, () -> assertTrue(n % 2 == 0)));
    }

    @TestFactory
    Stream<DynamicTest> generateRandomNumberOfTests() {

        // Generates random positive integers between 0 and 100 until
        // a number evenly divisible by 7 is encountered.
        Iterator<Integer> inputGenerator = new Iterator<Integer>() {

            Random random = new Random();
            int current;

            @Override
            public boolean hasNext() {
                current = random.nextInt(100);
                return current % 7 != 0;
            }

            @Override
            public Integer next() {
                return current;
            }
        };

        // Generates display names like: input:5, input:37, input:85, etc.
        Function<Integer, String> displayNameGenerator = (input) -> "input:" + input;

        // Executes tests based on the current input value.
        ThrowingConsumer<Integer> testExecutor = (input) -> assertTrue(input % 7 != 0);

        // Returns a stream of dynamic tests.
        return DynamicTest.stream(inputGenerator, displayNameGenerator, testExecutor);
    }

    @TestFactory
    Stream<DynamicNode> dynamicTestsWithContainers() {
        return Stream.of("A", "B", "C")
            .map(input -> dynamicContainer("Container " + input, Stream.of(
                dynamicTest("not null", () -> assertNotNull(input)),
                dynamicContainer("properties", Stream.of(
                    dynamicTest("length > 0", () -> assertTrue(input.length() > 0)),
                    dynamicTest("not empty", () -> assertFalse(input.isEmpty()))
                ))
            )));
    }

}

4. Running Tests

4.1. IDE Support

4.1.1. IntelliJ IDEA

IntelliJ IDEA supports running tests on the JUnit Platform since version 2016.2. For details please see the post on the IntelliJ IDEA blog.

Table 1. JUnit 5 Versions Bundled in IntelliJ IDEA
IntelliJ IDEA Version Bundled JUnit 5 Version

2016.2

M2

2016.3.1

M3

2017.1.2

M4

IntelliJ IDEA bundles a certain version of JUnit 5. That means, if you want to use the a newer milestone version of the Jupiter API, executing the tests might not work. This situation will improve once the first GA version of JUnit 5 has been released. In the meantime, please follow the instructions below to use an newer version of JUnit 5 than the one with IntelliJ IDEA.

In order to use a different JUnit 5 version, you have to manually add the junit-platform-launcher, junit-jupiter-engine, and junit-vintage-engine JARs to the classpath.

Additional Gradle Dependencies
// Only needed to run tests in an IntelliJ IDEA that bundles an older version
testRuntime("org.junit.platform:junit-platform-launcher:1.0.0-SNAPSHOT")
testRuntime("org.junit.jupiter:junit-jupiter-engine:5.0.0-SNAPSHOT")
testRuntime("org.junit.vintage:junit-vintage-engine:4.12.0-SNAPSHOT")
Additional Maven Dependencies
<!-- Only required to run tests in an IntelliJ IDEA that bundles an older version -->
<dependency>
    <groupId>org.junit.platform</groupId>
    <artifactId>junit-platform-launcher</artifactId>
    <version>1.0.0-SNAPSHOT</version>
    <scope>test</scope>
</dependency>
<dependency>
    <groupId>org.junit.jupiter</groupId>
    <artifactId>junit-jupiter-engine</artifactId>
    <version>5.0.0-SNAPSHOT</version>
    <scope>test</scope>
</dependency>
<dependency>
    <groupId>org.junit.vintage</groupId>
    <artifactId>junit-vintage-engine</artifactId>
    <version>4.12.0-SNAPSHOT</version>
    <scope>test</scope>
</dependency>

4.1.2. Eclipse Beta Support

Eclipse 4.7 (Oxygen) has beta support for the JUnit Platform and JUnit Jupiter. For details on how to set it up, please consult the Eclipse JDT UI/JUnit 5 wiki page.

4.1.3. Other IDEs

At the time of this writing, there is no direct support for running tests on the JUnit Platform within IDEs other than with IntelliJ IDEA or the beta support in Eclipse. However, the JUnit team provides two intermediate solutions so that you can go ahead and try out JUnit 5 within your IDE today. You can use the Console Launcher manually or execute tests with a JUnit 4 based Runner.

4.2. Build Support

4.2.1. Gradle

The JUnit team has developed a very basic Gradle plugin that allows you to run any kind of test that is supported by a TestEngine (e.g., JUnit 3, JUnit 4, JUnit Jupiter, Specsy, etc.). See build.gradle in the junit5-gradle-consumer project for an example of the plugin in action.

Enabling the JUnit Gradle Plugin

To use the JUnit Gradle plugin, you first need to make sure that you are running Gradle 2.5 or higher. Once you’ve done that, you can configure build.gradle as follows.

buildscript {
    repositories {
        mavenCentral()
        // The following is only necessary if you want to use SNAPSHOT releases.
        // maven { url 'https://oss.sonatype.org/content/repositories/snapshots' }
    }
    dependencies {
        classpath 'org.junit.platform:junit-platform-gradle-plugin:1.0.0-SNAPSHOT'
    }
}

apply plugin: 'org.junit.platform.gradle.plugin'
Configuring the JUnit Gradle Plugin

Once the JUnit Gradle plugin has been applied, you can configure it as follows.

These options are very likely to change as we continue to work towards the final release.
junitPlatform {
    platformVersion 1.0
    logManager 'org.apache.logging.log4j.jul.LogManager'
    reportsDir file('build/test-results/junit-platform') // this is the default
    // enableStandardTestTask true
    // selectors (optional)
    // filters (optional)
}

Setting logManager instructs the JUnit Gradle plugin to set the java.util.logging.manager system property to the supplied fully qualified class name of the java.util.logging.LogManager implementation to use. The above example demonstrates how to configure log4j as the LogManager.

By default, the JUnit Gradle plugin disables the standard Gradle test task, but this can be overridden via the enableStandardTestTask flag.

Configuring Selectors

By default, the plugin will scan your project’s output directories for tests. However, you can specify which tests to execute explicitly using the selectors extension element.

junitPlatform {
    // ...
    selectors {
        uris 'file:///foo.txt', 'http://example.com/'
        uri 'foo:resource' (1)
        files 'foo.txt', 'bar.csv'
        file 'qux.json' (2)
        directories 'foo/bar', 'bar/qux'
        directory 'qux/bar' (3)
        packages 'com.acme.foo', 'com.acme.bar'
        aPackage 'com.example.app' (4)
        classes 'com.acme.Foo', 'com.acme.Bar'
        aClass 'com.example.app.Application' (5)
        methods 'com.acme.Foo#a', 'com.acme.Foo#b'
        method 'com.example.app.Application#run(java.lang.String[])' (6)
        resources '/bar.csv', '/foo/input.json'
        resource '/com/acme/my.properties' (7)
    }
    // ...
}
1 URIs
2 Local files
3 Local directories
4 Packages
5 Classes, fully qualified class names
6 Methods, fully qualified method names (see selectMethod(String) in DiscoverySelectors)
7 Classpath resources
Configuring Filters

You can configure filters for the test plan by using the filters extension. By default, all engines and tags are included in the test plan. Only the default includeClassNamePattern (^.*Tests?$) is applied. You can override the default pattern as in the following example. When you specify multiple patterns, they are combined using OR semantics.

junitPlatform {
    // ...
    filters {
        engines {
            include 'junit-jupiter'
            // exclude 'junit-vintage'
        }
        tags {
            include 'fast', 'smoke'
            // exclude 'slow', 'ci'
        }
        packages {
            include 'com.sample.included1', 'com.sample.included2'
            // exclude 'com.sample.excluded1', 'com.sample.excluded2'
        }
        includeClassNamePattern '.*Spec'
        includeClassNamePatterns '.*Test', '.*Tests'
    }
    // ...
}

If you supply a Test Engine ID via engines {include …​} or engines {exclude …​}, the JUnit Gradle plugin will only run tests for the desired test engines. Similarly, if you supply a tag via tags {include …​} or tags {exclude …​}, the JUnit Gradle plugin will only run tests that are tagged accordingly (e.g., via the @Tag annotation for JUnit Jupiter based tests). The same applies to package names that can be included or excluded using packages {include …​} or packages {exclude …​}.

Configuring Test Engines

In order to have the JUnit Gradle plugin run any tests at all, a TestEngine implementation must be on the classpath.

To configure support for JUnit Jupiter based tests, configure a testCompile dependency on the JUnit Jupiter API and a testRuntime dependency on the JUnit Jupiter TestEngine implementation similar to the following.

dependencies {
    testCompile("org.junit.jupiter:junit-jupiter-api:5.0.0-SNAPSHOT")
    testRuntime("org.junit.jupiter:junit-jupiter-engine:5.0.0-SNAPSHOT")
}

The JUnit Gradle plugin can run JUnit 4 based tests as long as you configure a testCompile dependency on JUnit 4 and a testRuntime dependency on the JUnit Vintage TestEngine implementation similar to the following.

dependencies {
    testCompile("junit:junit:4.12")
    testRuntime("org.junit.vintage:junit-vintage-engine:4.12.0-SNAPSHOT")
}
Using the JUnit Gradle Plugin

Once the JUnit Gradle plugin has been applied and configured, you have a new junitPlatformTest task at your disposal.

Invoking gradlew junitPlatformTest (or gradlew test) from the command line will execute all tests within the project whose class names match the regular expression supplied via the includeClassNamePattern (which defaults to ^.*Tests?$).

Executing the junitPlatformTest task in the junit5-gradle-consumer project results in output similar to the following:

:junitPlatformTest

Test run finished after 93 ms
[         3 containers found      ]
[         0 containers skipped    ]
[         3 containers started    ]
[         0 containers aborted    ]
[         3 containers successful ]
[         0 containers failed     ]
[         3 tests found           ]
[         1 tests skipped         ]
[         2 tests started         ]
[         0 tests aborted         ]
[         2 tests successful      ]
[         0 tests failed          ]

BUILD SUCCESSFUL

If a test fails, the build will fail with output similar to the following:

:junitPlatformTest

Test failures (1):
  JUnit Jupiter:SecondTest:mySecondTest()
    MethodSource [className = 'com.example.project.SecondTest', methodName = 'mySecondTest', methodParameterTypes = '']
    => Exception: 2 is not equal to 1 ==> expected: <2> but was: <1>

Test run finished after 99 ms
[         3 containers found      ]
[         0 containers skipped    ]
[         3 containers started    ]
[         0 containers aborted    ]
[         3 containers successful ]
[         0 containers failed     ]
[         3 tests found           ]
[         0 tests skipped         ]
[         3 tests started         ]
[         0 tests aborted         ]
[         2 tests successful      ]
[         1 tests failed          ]

:junitPlatformTest FAILED

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':junitPlatformTest'.
> Process 'command '/Library/Java/JavaVirtualMachines/jdk1.8.0_92.jdk/Contents/Home/bin/java'' finished with non-zero exit value 1
The exit value is 1 if any containers or tests failed; otherwise, it is 0.
Current Limitations of the JUnit Gradle Plugin
The results of any tests run via the JUnit Gradle plugin will not be included in the standard test report generated by Gradle; however, the test results can typically be aggregated on a CI server. See the reportsDir property of the plugin.

4.2.2. Maven

The JUnit team has developed a very basic provider for Maven Surefire that lets you run JUnit 4 and JUnit Jupiter tests via mvn test. The pom.xml file in the junit5-maven-consumer project demonstrates how to use it and can serve as a starting point.

Due to a memory leak in Surefire 2.20, the junit-platform-surefire-provider currently only works with Surefire 2.19.1.
...
<build>
    <plugins>
        ...
        <plugin>
            <artifactId>maven-surefire-plugin</artifactId>
            <version>2.19</version>
            <dependencies>
                <dependency>
                    <groupId>org.junit.platform</groupId>
                    <artifactId>junit-platform-surefire-provider</artifactId>
                    <version>1.0.0-SNAPSHOT</version>
                </dependency>
            </dependencies>
        </plugin>
    </plugins>
</build>
...
Configuring Test Engines

In order to have Maven Surefire run any tests at all, a TestEngine implementation must be added to the runtime classpath.

To configure support for JUnit Jupiter based tests, configure a test dependency on the JUnit Jupiter API, and add the JUnit Jupiter TestEngine implementation to the dependencies of the maven-surefire-plugin similar to the following.

...
<build>
    <plugins>
        ...
        <plugin>
            <artifactId>maven-surefire-plugin</artifactId>
            <version>2.19</version>
            <dependencies>
                <dependency>
                    <groupId>org.junit.platform</groupId>
                    <artifactId>junit-platform-surefire-provider</artifactId>
                    <version>1.0.0-SNAPSHOT</version>
                </dependency>
                <dependency>
                    <groupId>org.junit.jupiter</groupId>
                    <artifactId>junit-jupiter-engine</artifactId>
                    <version>5.0.0-SNAPSHOT</version>
                </dependency>
            </dependencies>
        </plugin>
    </plugins>
</build>
...
<dependencies>
    ...
    <dependency>
        <groupId>org.junit.jupiter</groupId>
        <artifactId>junit-jupiter-api</artifactId>
        <version>5.0.0-SNAPSHOT</version>
        <scope>test</scope>
    </dependency>
</dependencies>
...

The JUnit Platform Surefire Provider can run JUnit 4 based tests as long as you configure a test dependency on JUnit 4 and add the JUnit Vintage TestEngine implementation to the dependencies of the maven-surefire-plugin similar to the following.

...
<build>
    <plugins>
        ...
        <plugin>
            <artifactId>maven-surefire-plugin</artifactId>
            <version>2.19</version>
            <dependencies>
                <dependency>
                    <groupId>org.junit.platform</groupId>
                    <artifactId>junit-platform-surefire-provider</artifactId>
                    <version>1.0.0-SNAPSHOT</version>
                </dependency>
                ...
                <dependency>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                    <version>4.12.0-SNAPSHOT</version>
                </dependency>
            </dependencies>
        </plugin>
    </plugins>
</build>
...
<dependencies>
    ...
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.12</version>
        <scope>test</scope>
    </dependency>
</dependencies>
...
Filtering by tags

You can filter tests by tags using the following configuration properties.

  • to include a tag, use either groups or includeTags

  • to exclude a tag, use either excludedGroups or excludeTags

...
<build>
    <plugins>
        ...
        <plugin>
            <artifactId>maven-surefire-plugin</artifactId>
            <version>2.19</version>
            <configuration>
                <properties>
                    <includeTags>acceptance</includeTags>
                    <excludeTags>integration, regression</excludeTags>
                </properties>
            </configuration>
            <dependencies>
                ...
            </dependencies>
        </plugin>
    </plugins>
</build>
...

4.3. Console Launcher

The ConsoleLauncher is a command-line Java application that lets you launch the JUnit Platform from the console. For example, it can be used to run JUnit Vintage and JUnit Jupiter tests and print test execution results to the console.

An executable junit-platform-console-standalone-1.0.0-SNAPSHOT.jar with all dependencies included is published in the central Maven repository under the junit-platform-console-standalone directory. You can run the standalone ConsoleLauncher as shown below.

java -jar junit-platform-console-standalone-1.0.0-SNAPSHOT.jar <Options>

Here’s an example of its output:

├─ JUnit Vintage
│  └─ example.JUnit4Tests
│     └─ standardJUnit4Test ✔
└─ JUnit Jupiter
   ├─ StandardTests
   │  ├─ succeedingTest() ✔
   │  └─ skippedTest() ↷ for demonstration purposes
   └─ A special test case
      ├─ Custom test name containing spaces ✔
      ├─ ╯°□°)╯ ✔
      └─ 😱 ✔

Test run finished after 64 ms
[         5 containers found      ]
[         0 containers skipped    ]
[         5 containers started    ]
[         0 containers aborted    ]
[         5 containers successful ]
[         0 containers failed     ]
[         6 tests found           ]
[         1 tests skipped         ]
[         5 tests started         ]
[         0 tests aborted         ]
[         5 tests successful      ]
[         0 tests failed          ]
Exit Code
The ConsoleLauncher exits with a status code of 1 if any containers or tests failed. Otherwise the exit code is 0.

4.3.1. Options

These options are very likely to change as we continue to work towards the final release.
Option                                        Description
------                                        -----------
-h, --help                                    Display help information.
--disable-ansi-colors                         Disable ANSI colors in output (not
                                                supported by all terminals).
--details <[none,flat,tree,verbose]>          Select an output details mode for when
                                                tests are executed. Use one of: [none,
                                                flat, tree, verbose]. If 'none' is
                                                selected, then only the summary and test
                                                failures are shown. (default: tree)
--details-theme <[ascii,unicode]>             Select an output details tree theme for
                                                when tests are executed. Use one of:
                                                [ascii, unicode] (default: unicode)
--class-path, --classpath, --cp <Path:        Provide additional classpath entries --
  path1:path2:...>                              for example, for adding engines and
                                                their dependencies. This option can be
                                                repeated.
--reports-dir <Path>                          Enable report output into a specified
                                                local directory (will be created if it
                                                does not exist).
--scan-class-path, --scan-classpath [Path:    Scan all directories on the classpath or
  path1:path2:...]                              explicit classpath roots. Without
                                                arguments, only directories on the
                                                system classpath as well as additional
                                                classpath entries supplied via -cp
                                                (directories and JAR files) are scanned.
                                                Explicit classpath roots that are not on
                                                the classpath will be silently ignored.
                                                This option can be repeated.
-u, --select-uri <URI>                        Select a URI for test discovery. This
                                                option can be repeated.
-f, --select-file <String>                    Select a file for test discovery. This
                                                option can be repeated.
-d, --select-directory <String>               Select a directory for test discovery.
                                                This option can be repeated.
-p, --select-package <String>                 Select a package for test discovery. This
                                                option can be repeated.
-c, --select-class <String>                   Select a class for test discovery. This
                                                option can be repeated.
-m, --select-method <String>                  Select a method for test discovery. This
                                                option can be repeated.
-r, --select-resource <String>                Select a classpath resource for test
                                                discovery. This option can be repeated.
-n, --include-classname <String>              Provide a regular expression to include
                                                only classes whose fully qualified names
                                                match. To avoid loading classes
                                                unnecessarily, the default pattern only
                                                includes class names that end with
                                                "Test" or "Tests". When this option is
                                                repeated, all patterns will be combined
                                                using OR semantics. (default: ^.*Tests?$)
-N, --exclude-classname <String>              Provide a regular expression to exclude
                                                those classes whose fully qualified
                                                names match. When this option is
                                                repeated, all patterns will be combined
                                                using OR semantics.
--include-package <String>                    Provide a package to be included in the
                                                test run. This option can be repeated.
--exclude-package <String>                    Provide a package to be excluded from the
                                                test run. This option can be repeated.
-t, --include-tag <String>                    Provide a tag to be included in the test
                                                run. This option can be repeated.
-T, --exclude-tag <String>                    Provide a tag to be excluded from the test
                                                run. This option can be repeated.
-e, --include-engine <String>                 Provide the ID of an engine to be included
                                                in the test run. This option can be
                                                repeated.
-E, --exclude-engine <String>                 Provide the ID of an engine to be excluded
                                                from the test run. This option can be
                                                repeated.

4.4. Using JUnit 4 to Run the JUnit Platform

The JUnitPlatform runner is a JUnit 4 based Runner which enables you to run any test whose programming model is supported on the JUnit Platform in a JUnit 4 environment — for example, a JUnit Jupiter test class.

Annotating a class with @RunWith(JUnitPlatform.class) allows it to be run with IDEs and build systems that support JUnit 4 but do not yet support the JUnit Platform directly.

Since the JUnit Platform has features that JUnit 4 does not have, the runner is only able to support a subset of the JUnit Platform functionality, especially with regard to reporting (see Display Names vs. Technical Names). But for the time being the JUnitPlatform runner is an easy way to get started.

4.4.1. Setup

You need the following artifacts and their dependencies on the classpath. See Dependency Metadata for details regarding group IDs, artifact IDs, and versions.

Explicit Dependencies
  • junit-4.12.jar in test scope: to run tests using JUnit 4.

  • junit-platform-runner in test scope: location of the JUnitPlatform runner

  • junit-jupiter-api in test scope: API for writing tests, including @Test, etc.

  • junit-jupiter-engine in test runtime scope: implementation of the Engine API for JUnit Jupiter

Transitive Dependencies
  • junit-platform-launcher in test scope

  • junit-platform-engine in test scope

  • junit-platform-commons in test scope

  • opentest4j in test scope

4.4.2. Display Names vs. Technical Names

By default, display names will be used for test artifacts; however, when the JUnitPlatform runner is used to execute tests with a build tool such as Gradle or Maven, the generated test report often needs to include the technical names of test artifacts — for example, fully qualified class names — instead of shorter display names like the simple name of a test class or a custom display name containing special characters. To enable technical names for reporting purposes, simply declare the @UseTechnicalNames annotation alongside @RunWith(JUnitPlatform.class).

4.4.3. Single Test Class

One way to use the JUnitPlatform runner is to annotate a test class with @RunWith(JUnitPlatform.class) directly. Please note that the test methods in the following example are annotated with org.junit.jupiter.api.Test (JUnit Jupiter), not org.junit.Test (JUnit Vintage). Moreover, in this case the test class must be public; otherwise, IDEs won’t recognize it as a JUnit 4 test class.

import static org.junit.jupiter.api.Assertions.fail;

import org.junit.jupiter.api.Test;
import org.junit.platform.runner.JUnitPlatform;
import org.junit.runner.RunWith;

@RunWith(JUnitPlatform.class)
public class JUnit4ClassDemo {

    @Test
    void succeedingTest() {
        /* no-op */
    }

    @Test
    void failingTest() {
        fail("Failing for failing's sake.");
    }

}

4.4.4. Test Suite

If you have multiple test classes you can create a test suite as can be seen in the following example.

import org.junit.platform.runner.JUnitPlatform;
import org.junit.platform.suite.api.SelectPackages;
import org.junit.runner.RunWith;

@RunWith(JUnitPlatform.class)
@SelectPackages("example")
public class JUnit4SuiteDemo {
}

The JUnit4SuiteDemo will discover and run all tests in the example package and its subpackages. By default, it will only include test classes whose names match the pattern ^.*Tests?$.

Additional Configuration Options
There are more configuration options for discovering and filtering tests than just @SelectPackages. Please consult the Javadoc for further details.

5. Extension Model

5.1. Overview

In contrast to the competing Runner, @Rule, and @ClassRule extension points in JUnit 4, the JUnit Jupiter extension model consists of a single, coherent concept: the Extension API. Note, however, that Extension itself is just a marker interface.

5.2. Registering Extensions

Extensions can be registered explicitly via @ExtendWith or automatically via Java’s ServiceLoader mechanism.

5.2.1. Declarative Extension Registration

Developers can register one or more extensions declaratively by annotating a test interface, test class, test method, or custom composed annotation with @ExtendWith(…​) and supplying class references for the extensions to register.

For example, to register a custom MockitoExtension for a particular test method, you would annotate the test method as follows.

@ExtendWith(MockitoExtension.class)
@Test
void mockTest() {
    // ...
}

To register a custom MockitoExtension for all tests in a particular class and its subclasses, you would annotate the test class as follows.

@ExtendWith(MockitoExtension.class)
class MockTests {
    // ...
}

Multiple extensions can be registered together like this:

@ExtendWith({ FooExtension.class, BarExtension.class })
class MyTestsV1 {
    // ...
}

As an alternative, multiple extensions can be registered separately like this:

@ExtendWith(FooExtension.class)
@ExtendWith(BarExtension.class)
class MyTestsV2 {
    // ...
}

The execution of tests in both MyTestsV1 and MyTestsV2 will be extended by the FooExtension and BarExtension, in exactly that order.

5.2.2. Automatic Extension Registration

In addition to declarative extension registration support using annotations, JUnit Jupiter also supports global extension registration via Java’s java.util.ServiceLoader mechanism, allowing third-party extensions to be auto-detected and automatically registered based on what is available in the classpath.

Specifically, a custom extension can be registered by supplying its fully qualified class name in a file named org.junit.jupiter.api.extension.Extension within the /META-INF/services folder in its enclosing JAR file.

Enabling Automatic Extension Detection

Auto-detection is an advanced feature and is therefore not enabled by default. To enable it, simply set the junit.extensions.autodetection.enabled configuration key to true. This can be supplied as a JVM system property or as a configuration parameter in the LauncherDiscoveryRequest that is passed to the Launcher.

For example, to enable auto-detection of extensions, you can start your JVM with the following system property.

-Djunit.extensions.autodetection.enabled=true

When auto-detection is enabled, extensions discovered via the ServiceLoader mechanism will be added to the extension registry after JUnit Jupiter’s global extensions (e.g., support for TestInfo, TestReporter, etc.).

5.2.3. Extension Inheritance

Registered extensions are inherited within test class hierarchies with top-down semantics. Similarly, extensions registered at the class-level are inherited at the method-level. Furthermore, a specific extension implementation can only be registered once for a given extension context and its parent contexts. Consequently, any attempt to register a duplicate extension implementation will be ignored.

5.3. Conditional Test Execution

ContainerExecutionCondition and TestExecutionCondition define the Extension APIs for programmatic, conditional test execution.

A ContainerExecutionCondition is evaluated to determine if all tests in a given container (e.g., a test class) should be executed based on the supplied ContainerExtensionContext. Similarly, a TestExecutionCondition is evaluated to determine if a given test method should be executed based on the supplied TestExtensionContext.

When multiple ContainerExecutionCondition or TestExecutionCondition extensions are registered, a container or test, respectively, is disabled as soon as one of the conditions returns disabled. Thus, there is no guarantee that a condition is evaluated because another extension might have already caused a container or test to be disabled. In other words, the evaluation works like the short-circuiting boolean OR operator.

See the source code of DisabledCondition and @Disabled for concrete examples.

5.3.1. Deactivating Conditions

Sometimes it can be useful to run a test suite without certain conditions being active. For example, you may wish to run tests even if they are annotated with @Disabled in order to see if they are still broken. To do this, simply provide a pattern for the junit.conditions.deactivate configuration key to specify which conditions should be deactivated (i.e., not evaluated) for the current test run. The pattern can be supplied as a JVM system property or as a configuration parameter in the LauncherDiscoveryRequest that is passed to the Launcher.

For example, to deactivate JUnit’s @Disabled condition, you can start your JVM with the following system property.

-Djunit.conditions.deactivate=org.junit.*DisabledCondition

Pattern Matching Syntax

If the junit.conditions.deactivate pattern consists solely of an asterisk (*), all conditions will be deactivated. Otherwise, the pattern will be used to match against the fully qualified class name (FQCN) of each registered condition. Any dot (.) in the pattern will match against a dot (.) or a dollar sign ($) in the FQCN. Any asterisk (*) will match against one or more characters in the FQCN. All other characters in the pattern will be matched one-to-one against the FQCN.

Examples:

  • *: deactivates all conditions.

  • org.junit.*: deactivates every condition under the org.junit base package and any of its subpackages.

  • *.MyCondition: deactivates every condition whose simple class name is exactly MyCondition.

  • *System*: deactivates every condition whose simple class name contains System.

  • org.example.MyCondition: deactivates the condition whose FQCN is exactly org.example.MyCondition.

5.4. Test Instance Post-processing

TestInstancePostProcessor defines the API for Extensions that wish to post process test instances.

Common use cases include injecting dependencies into the test instance, invoking custom initialization methods on the test instance, etc.

For concrete examples, consult the source code for the MockitoExtension and the SpringExtension.

5.5. Parameter Resolution

ParameterResolver defines the Extension API for dynamically resolving parameters at runtime.

If a test constructor or a @Test, @TestFactory, @BeforeEach, @AfterEach, @BeforeAll, or @AfterAll method accepts a parameter, the parameter must be resolved at runtime by a ParameterResolver. A ParameterResolver can either be built-in (see TestInfoParameterResolver) or registered by the user. Generally speaking, parameters may be resolved by name, type, annotation, or any combination thereof. For concrete examples, consult the source code for CustomTypeParameterResolver and CustomAnnotationParameterResolver.

5.6. Test Lifecycle Callbacks

The following interfaces define the APIs for extending tests at various points in the test execution lifecycle. Consult the following sections for examples and the Javadoc for each of these interfaces in the org.junit.jupiter.api.extension package for further details.

Implementing Multiple Extension APIs
Extension developers may choose to implement any number of these interfaces within a single extension. Consult the source code of the SpringExtension for a concrete example.

5.6.1. Before and After Test Execution Callbacks

BeforeTestExecutionCallback and AfterTestExecutionCallback define the APIs for Extensions that wish to add behavior that will be executed immediately before and immediately after a test method is executed, respectively. As such, these callbacks are well suited for timing, tracing, and similar use cases. If you need to implement callbacks that are invoked around @BeforeEach and @AfterEach methods, implement BeforeEachCallback and AfterEachCallback instead.

The following example shows how to use these callbacks to calculate and log the execution time of a test method. TimingExtension implements both BeforeTestExecutionCallback and AfterTestExecutionCallback in order to time and log the test execution.

An extension that times and logs the execution of test methods
import java.lang.reflect.Method;
import java.util.logging.Logger;

import org.junit.jupiter.api.extension.AfterTestExecutionCallback;
import org.junit.jupiter.api.extension.BeforeTestExecutionCallback;
import org.junit.jupiter.api.extension.ExtensionContext.Namespace;
import org.junit.jupiter.api.extension.ExtensionContext.Store;
import org.junit.jupiter.api.extension.TestExtensionContext;

public class TimingExtension implements BeforeTestExecutionCallback, AfterTestExecutionCallback {

    private static final Logger LOG = Logger.getLogger(TimingExtension.class.getName());

    @Override
    public void beforeTestExecution(TestExtensionContext context) throws Exception {
        getStore(context).put(context.getTestMethod().get(), System.currentTimeMillis());
    }

    @Override
    public void afterTestExecution(TestExtensionContext context) throws Exception {
        Method testMethod = context.getTestMethod().get();
        long start = getStore(context).remove(testMethod, long.class);
        long duration = System.currentTimeMillis() - start;

        LOG.info(() -> String.format("Method [%s] took %s ms.", testMethod.getName(), duration));
    }

    private Store getStore(TestExtensionContext context) {
        return context.getStore(Namespace.create(getClass(), context));
    }

}

Since the TimingExtensionTests class registers the TimingExtension via @ExtendWith, its tests will have this timing applied when they execute.

A test class that uses the example TimingExtension
@ExtendWith(TimingExtension.class)
class TimingExtensionTests {

    @Test
    void sleep20ms() throws Exception {
        Thread.sleep(20);
    }

    @Test
    void sleep50ms() throws Exception {
        Thread.sleep(50);
    }

}

The following is an example of the logging produced when TimingExtensionTests is run.

INFO: Method [sleep20ms] took 24 ms.
INFO: Method [sleep50ms] took 53 ms.

5.7. Exception Handling

TestExecutionExceptionHandler defines the API for Extensions that wish to handle exceptions thrown during test execution.

The following example shows an extension which will swallow all instances of IOException but rethrow any other type of exception.

An exception handling extension
public class IgnoreIOExceptionExtension implements TestExecutionExceptionHandler {

    @Override
    public void handleTestExecutionException(TestExtensionContext context, Throwable throwable)
            throws Throwable {

        if (throwable instanceof IOException) {
            return;
        }
        throw throwable;
    }
}

5.8. Keeping State in Extensions

Usually, an extension is instantiated only once. So the question becomes relevant: How do you keep the state from one invocation of an extension to the next? The ExtensionContext API provides a Store exactly for this purpose. Extensions may put values into a store for later retrieval. See the TimingExtension for an example of using the Store with a method-level scope. It is important to remember that values stored in a TestExtensionContext during test execution will not be available in the surrounding ContainerExtensionContext. Since ContainerExtensionContexts may be nested, the scope of inner contexts may also be limited. Consult the corresponding Javadoc for details on the methods available for storing and retrieving values via the Store.

5.9. Supported Utilities in Extensions

The JUnit Platform Commons artifact exposes a package named org.junit.platform.commons.support that contains maintained utility methods for working with annotations, reflection, and classpath scanning tasks. TestEngine and Extension authors are encouraged to use these supported methods in order to align with the behavior of the JUnit Platform.

5.10. Relative Execution Order of User Code and Extensions

When executing a test class that contains one or more test methods, a number of extension callbacks are called in addition to the user-provided test and lifecycle methods. The following diagram illustrates the relative order of user-provided code and extension code.

extensions lifecycle
Figure 2: User code and extension code

User-provided test and lifecycle methods are shown in orange, with callback code provided by extensions shown in blue. The grey box denotes the execution of a single test method and will be repeated for every test method in the test class.

The following table further explains the twelve steps in Figure 2.

Step Interface/Annotation Description

1

interface org.junit.jupiter.api.extension.BeforeAllCallback

extension code executed before all tests of the container are executed

2

annotation org.junit.jupiter.api.BeforeAll

user code executed before all tests of the container are executed

3

interface org.junit.jupiter.api.extension.BeforeEachCallback

extension code executed before each test is executed

4

annotation org.junit.jupiter.api.BeforeEach

user code executed before each test is executed

5

interface org.junit.jupiter.api.extension.BeforeTestExecutionCallback

extension code executed immediately before a test is executed

6

annotation org.junit.jupiter.api.Test

user code of the actual test method

7

interface org.junit.jupiter.api.extension.TestExecutionExceptionHandler

extension code for handling exceptions thrown during a test

8

interface org.junit.jupiter.api.extension.AfterTestExecutionCallback

extension code executed immediately after test execution and its corresponding exception handlers

9

annotation org.junit.jupiter.api.AfterEach

user code executed after each test is executed

10

interface org.junit.jupiter.api.extension.AfterEachCallback

extension code executed after each test is executed

11

annotation org.junit.jupiter.api.AfterAll

user code executed after all tests of the container are executed

12

interface org.junit.jupiter.api.extension.AfterAllCallback

extension code executed after all tests of the container are executed

In the simplest case only the actual test method will be executed (step 6); all other steps are optional depending on the presence of user code or extension support for the corresponding lifecycle callback. For further details on the various lifecycle callbacks please consult the respective JavaDoc for each annotation and extension.

6. Migrating from JUnit 4

Although the JUnit Jupiter programming model and extension model will not support JUnit 4 features such as Rules and Runners natively, it is not expected that source code maintainers will need to update all of their existing tests, test extensions, and custom build test infrastructure to migrate to JUnit Jupiter.

Instead, JUnit provides a gentle migration path via a JUnit Vintage test engine which allows existing tests based on JUnit 3 and JUnit 4 to be executed using the JUnit Platform infrastructure. Since all classes and annotations specific to JUnit Jupiter reside under a new org.junit.jupiter base package, having both JUnit 4 and JUnit Jupiter in the classpath does not lead to any conflicts. It is therefore safe to maintain existing JUnit 4 tests alongside JUnit Jupiter tests. Furthermore, since the JUnit team will continue to provide maintenance and bug fix releases for the JUnit 4.x baseline, developers have plenty of time to migrate to JUnit Jupiter on their own schedule.

6.1. Running JUnit 4 Tests on the JUnit Platform

Just make sure that the junit-vintage-engine artifact is in your test runtime path. In that case JUnit 3 and JUnit 4 tests will automatically be picked up by the JUnit Platform launcher.

See the example projects in the junit5-samples repository to find out how this is done with Gradle and Maven.

6.2. Migration Tips

The following are things you have to watch out for when migrating existing JUnit 4 tests to JUnit Jupiter.

  • Annotations reside in the org.junit.jupiter.api package.

  • Assertions reside in org.junit.jupiter.api.Assertions.

  • Assumptions reside in org.junit.jupiter.api.Assumptions.

  • @Before and @After no longer exist; use @BeforeEach and @AfterEach instead.

  • @BeforeClass and @AfterClass no longer exist; use @BeforeAll and @AfterAll instead.

  • @Ignore no longer exists: use @Disabled instead.

  • @Category no longer exists; use @Tag instead.

  • @RunWith no longer exists; superseded by @ExtendWith.

  • @Rule and @ClassRule no longer exist; superseded by @ExtendWith; see the following section for partial rule support.

6.3. Limited JUnit 4 Rule Support

As stated above, JUnit Jupiter does not and will not support JUnit 4 rules natively. The JUnit team realizes, however, that many organizations, especially large ones, are likely to have large JUnit 4 codebases including custom rules. To serve these organizations and enable a gradual migration path the JUnit team has decided to support a selection of JUnit 4 rules verbatim within JUnit Jupiter. This support is based on adapters and is limited to those rules that are semantically compatible to the JUnit Jupiter extension model, i.e. those that do not completely change the overall execution flow of the test.

JUnit Jupiter currently supports the following three Rule types including subclasses of those types:

  • org.junit.rules.ExternalResource (including org.junit.rules.TemporaryFolder)

  • org.junit.rules.Verifier (including org.junit.rules.ErrorCollector)

  • org.junit.rules.ExpectedException

As in JUnit 4, Rule-annotated fields as well as methods are supported. By using these class-level extensions on a test class such Rule implementations in legacy codebases can be left unchanged including the JUnit 4 rule import statements.

This limited form of Rule support can be switched on by the class-level annotation org.junit.jupiter.migrationsupport.rules.EnableRuleMigrationSupport. This annotation is a composed annotation which enables all migration support extensions: VerifierSupport, ExternalResourceSupport, and ExpectedExceptionSupport.

However, if you intend to develop a new extension for JUnit 5 please use the new extension model of JUnit Jupiter instead of the rule-based model of JUnit 4.

7. Advanced Topics

7.1. JUnit Platform Launcher API

One of the prominent goals of JUnit 5 is to make the interface between JUnit and its programmatic clients – build tools and IDEs – more powerful and stable. The purpose is to decouple the internals of discovering and executing tests from all the filtering and configuration that’s necessary from the outside.

JUnit 5 introduces the concept of a Launcher that can be used to discover, filter, and execute tests. Moreover, third party test libraries – like Spock, Cucumber, and FitNesse – can plug into the JUnit Platform’s launching infrastructure by providing a custom TestEngine.

The launching API is in the junit-platform-launcher module.

An example consumer of the launching API is the ConsoleLauncher in the junit-platform-console project.

7.1.1. Discovering Tests

Introducing test discovery as a dedicated feature of the platform itself will (hopefully) free IDEs and build tools from most of the difficulties they had to go through to identify test classes and test methods in the past.

Usage Example:

import static org.junit.platform.engine.discovery.ClassNameFilter.includeClassNamePatterns;
import static org.junit.platform.engine.discovery.DiscoverySelectors.selectClass;
import static org.junit.platform.engine.discovery.DiscoverySelectors.selectPackage;

import org.junit.jupiter.api.Test;
import org.junit.platform.launcher.Launcher;
import org.junit.platform.launcher.LauncherDiscoveryRequest;
import org.junit.platform.launcher.TestExecutionListener;
import org.junit.platform.launcher.TestPlan;
import org.junit.platform.launcher.core.LauncherDiscoveryRequestBuilder;
import org.junit.platform.launcher.core.LauncherFactory;
import org.junit.platform.launcher.listeners.SummaryGeneratingListener;
LauncherDiscoveryRequest request = LauncherDiscoveryRequestBuilder.request()
    .selectors(
        selectPackage("com.example.mytests"),
        selectClass(MyTestClass.class)
    )
    .filters(includeClassNamePatterns(".*Test"))
    .build();

TestPlan plan = LauncherFactory.create().discover(request);

There’s currently the possibility to search for classes, methods, all classes in a package, or even all tests in the classpath. Discovery takes place across all participating test engines.

The resulting test plan is basically a hierarchical (and read-only) description of all engines, classes, and test methods that fit the specification object. The client can traverse the tree, retrieve details about a node, and get a link to the original source (like class, method, or file position). Every node in the test plan tree has a unique ID that can be used to invoke a particular test or group of tests.

7.1.2. Executing Tests

There are two ways to execute tests. Clients can either use the same test specification object as in the discovery phase, or – to speed things up a bit – pass in the prepared TestPlan object from a previous discovery step. Test progress and result reporting can be achieved through a TestExecutionListener:

LauncherDiscoveryRequest request = LauncherDiscoveryRequestBuilder.request()
    .selectors(
        selectPackage("com.example.mytests"),
        selectClass(MyTestClass.class)
    )
    .filters(includeClassNamePatterns(".*Test"))
    .build();

Launcher launcher = LauncherFactory.create();

// Register a listener of your choice
TestExecutionListener listener = new SummaryGeneratingListener();
launcher.registerTestExecutionListeners(listener);

launcher.execute(request);

There’s currently no result object, but you can easily use a listener to aggregate the final results in an object of your own. For an example see the SummaryGeneratingListener.

7.1.3. Plugging in Your Own Test Engine

JUnit currently provides two TestEngine implementations out of the box:

Third parties may also contribute their own TestEngine by implementing the interfaces in the junit-platform-engine module and registering their engine. Engine registration is currently supported via Java’s java.util.ServiceLoader mechanism. For example, the junit-jupiter-engine module registers its org.junit.jupiter.engine.JupiterTestEngine in a file named org.junit.platform.engine.TestEngine within the /META-INF/services in the junit-jupiter-engine JAR.

7.1.4. Plugging in Your Own Test Execution Listeners

In addition to the public Launcher API method for registering test execution listeners programmatically, custom TestExecutionListener implementations discovered at runtime via Java’s java.util.ServiceLoader facility are automatically registered with the DefaultLauncher. For example, an example.TestInfoPrinter class implementing TestExecutionListener and declared within the /META-INF/services/org.junit.platform.launcher.TestExecutionListener file is loaded and registered automatically.

8. API Evolution

One of the major goals of JUnit 5 is to improve maintainers' capabilities to evolve JUnit despite its being used in many projects. With JUnit 4 a lot of stuff that was originally added as an internal construct only got used by external extension writers and tool builders. That made changing JUnit 4 especially difficult and sometimes impossible.

That’s why JUnit 5 introduces a defined lifecycle for all publicly available interfaces, classes, and methods.

8.1. API Annotations

Every published artifact has a version number <major>.<minor>.<patch> and all publicly available interfaces, classes, and methods are annotated with @API. The annotation’s Usage value can be assigned one of the following five values:

Usage Description

Internal

Must not be used by any code other than JUnit itself. Might be removed without prior notice.

Deprecated

Should no longer be used; might disappear in the next minor release.

Experimental

Intended for new, experimental features where we are looking for feedback.
Use this element with caution; it might be promoted to Maintained or Stable in the future, but might also be removed without prior notice, even in a patch.

Maintained

Intended for features that will not be changed in a backwards- incompatible way for at least the next minor release of the current major version. If scheduled for removal, it will be demoted to Deprecated first.

Stable

Intended for features that will not be changed in a backwards- incompatible way in the current major version (5.*).

If the @API annotation is present on a type, it is considered to be applicable for all public members of that type as well. A member is allowed to declare a different Usage value of lower stability.

8.2. Tooling Support

The JUnit team plans to provide native tooling support for all JUnit users, extenders, and tool builders. The tooling support will provide a means to check if the JUnit APIs are being used in accordance with @API annotation declarations.

9. Contributors

Browse the current list of contributors directly on GitHub.

10. Release Notes

5.0.0-ALPHA

Date of Release: February 1, 2016

Scope: Alpha release of JUnit 5

5.0.0-M1

Date of Release: July 7, 2016

Scope: First milestone release of JUnit 5

Summary of Changes

The following is a list of global changes. For details regarding changes specific to the Platform, Jupiter, and Vintage, consult the dedicated subsections below. For a complete list of all closed issues and pull requests for this release, consult the 5.0 M1 milestone page in the JUnit repository on GitHub.

  • JAR manifests in published artifacts now contain additional metadata such as Created-By, Built-By, Build-Date, Build-Time, Build-Revision, Implementation-Title, Implementation-Version, Implementation-Vendor, etc.

  • Published artifacts now contain LICENSE.md in META-INF.

  • JUnit now participates in the Up For Grabs movement for open source contributions.

  • Group IDs, artifact IDs, and versions have changed for all published artifacts.

  • All base packages have been renamed.

Table 2. Artifact Migration
Old Group ID Old Artifact ID New Group ID New Artifact ID New Base Version

org.junit

junit-commons

org.junit.platform

junit-platform-commons

1.0.0

org.junit

junit-console

org.junit.platform

junit-platform-console

1.0.0

org.junit

junit-engine-api

org.junit.platform

junit-platform-engine

1.0.0

org.junit

junit-gradle

org.junit.platform

junit-platform-gradle-plugin

1.0.0

org.junit

junit-launcher

org.junit.platform

junit-platform-launcher

1.0.0

org.junit

junit4-runner

org.junit.platform

junit-platform-runner

1.0.0

org.junit

surefire-junit5

org.junit.platform

junit-platform-surefire-provider

1.0.0

org.junit

junit5-api

org.junit.jupiter

junit-jupiter-api

5.0.0

org.junit

junit5-engine

org.junit.jupiter

junit-jupiter-engine

5.0.0

org.junit

junit4-engine

org.junit.vintage

junit-vintage-engine

4.12.0

Table 3. Package Migration
Old Base Package New Base Package

org.junit.gen5.api

org.junit.jupiter.api

org.junit.gen5.commons

org.junit.platform.commons

org.junit.gen5.console

org.junit.platform.console

org.junit.gen5.engine.junit4

org.junit.vintage.engine

org.junit.gen5.engine.junit5

org.junit.jupiter.engine

org.junit.gen5.engine

org.junit.platform.engine

org.junit.gen5.gradle

org.junit.platform.gradle.plugin

org.junit.gen5.junit4.runner

org.junit.platform.runner

org.junit.gen5.launcher

org.junit.platform.launcher

org.junit.gen5.launcher.main

org.junit.platform.launcher.core

org.junit.gen5.surefire

org.junit.platform.surefire.provider

JUnit Platform

  • The ConsoleRunner has been renamed to ConsoleLauncher.

  • ConsoleLauncher now always returns the status code on exit, and the enable exit code flags have been removed.

  • The junit-platform-console artifact no longer defines transitive dependencies on junit-platform-runner, junit-jupiter-engine, or junit-vintage-engine.

  • The JUnit5 Runner has been renamed to JUnitPlatform.

    • @Packages has been renamed to @SelectPackages.

    • @Classes has been renamed to @SelectClasses.

    • @UniqueIds has been removed.

    • @UseTechnicalNames has been introduced.

  • The Gradle plugin for the JUnit Platform has been completely overhauled.

    • The JUnit Platform Gradle plugin now requires Gradle 2.5 or higher.

    • The junit5Test Gradle task has been renamed to junitPlatformTest.

    • The junit5 Gradle plugin configuration has been renamed to junitPlatform.

      • runJunit4 has been replaced by enableStandardTestTask.

      • version has been replaced by platformVersion.

    • See Gradle for further details.

  • XML test report generation has been overhauled.

    • XML reports now contain newlines.

    • Attributes specific to the JUnit Platform that do not align with standard attributes in the de facto standard XML schema are now contained in CDATA blocks within the <system-out> element.

    • XML reports now use real method names and fully qualified class names instead of display names.

  • Unique ID in TestIdentifier is now a String.

  • TestSource is now an interface with a dedicated hierarchy consisting of CompositeTestSource, JavaSource, JavaPackageSource, JavaClassSource, JavaMethodSource, UriSource, FileSystemSource, DirectorySource, and FileSource.

  • All DiscoverySelector factory methods have been moved to a new DiscoverySelectors class that serves as a centralized collection of all select methods.

  • Filter.filter() has been renamed to Filter.apply().

  • TestTag.of() has been renamed to TestTag.create().

  • TestDiscoveryRequest has been renamed to LauncherDiscoveryRequest.

  • TestDiscoveryRequestBuilder has been renamed to LauncherDiscoveryRequestBuilder.

  • LauncherDiscoveryRequest is now immutable.

  • TestDescriptor.allDescendants() has been renamed to TestDescriptor.getAllDescendants().

  • TestEngine#discover(EngineDiscoveryRequest) has been replaced by TestEngine#discover(EngineDiscoveryRequest, UniqueId).

  • Introduced ConfigurationParameters which the Launcher supplies to engines via the EngineDiscoveryRequest and ExecutionRequest

  • The Container and Leaf abstractions have been removed from the HierarchicalTestEngine.

  • The getName() method has been removed from TestIdentifier and TestDescriptor in favor of retrieving an implementation specific name via the TestSource.

  • Test engines are now permitted to be completely dynamic in nature. In other words, a TestEngine is no longer required to create TestDescriptor entries during the discovery phase; a TestEngine may now optionally register containers and tests dynamically during the execution phase.

  • Include and exclude support for engines and tags has been completely revised.

    • Engines and tags can no longer be required but rather included.

    • ConsoleLauncher now supports the following options: t/include-tag, T/exclude-tag, e/include-engine, E/exclude-engine.

    • The Gradle plugin now supports engines and tags configuration blocks with nested include and exclude entries.

    • EngineFilter now supports includeEngines() and excludeEngines() factory methods.

    • The JUnitPlatform runner now supports @IncludeTags, @ExcludeTags, @IncludeEngines, and @ExcludeEngines.

JUnit Jupiter

  • The junit5 engine ID has been renamed to junit-jupiter.

  • JUnit5TestEngine has been renamed to JupiterTestEngine.

  • Assertions now provides the following support:

    • assertEquals() for primitive types

    • assertEquals() for doubles and floats with deltas

    • assertArrayEquals()

    • Expected and actual values are now supplied to the AssertionFailedError.

  • Dynamic Tests: tests can now be registered dynamically at runtime via lambda expressions.

  • TestInfo now provides access to tags via getTags().

  • @AfterEach methods and after callbacks are now invoked if an exception is thrown by a @Test method, a @BeforeEach method, or a before callback.

  • @AfterAll methods and after all callbacks are now guaranteed to be invoked.

  • Repeatable annotations such as @ExtendWith and @Tag are now discovered in superclasses within a test class hierarchy as well as on interfaces.

  • Extensions are now registered top-down within a test class or interface hierarchy.

  • Test and container execution conditions can now be deactivated.

  • InstancePostProcessor has been renamed to TestInstancePostProcessor.

    • TestInstancePostProcessor implementations are now properly applied within @Nested test class hierarchies.

  • MethodParameterResolver has been renamed to ParameterResolver.

    • The ParameterResolver API is now based on java.lang.reflect.Executable and can therefore be used to resolve parameters for methods and constructors.

    • New ParameterContext which is passed to the supports() and resolve() methods of ParameterResolver extensions.

    • Resolution of primitive types is now supported for ParameterResolver extensions.

  • The ExtensionPointRegistry and ExtensionRegistrar have been removed in favor of declarative registration via @ExtendWith.

  • BeforeAllExtensionPoint has been renamed to BeforeAllCallback.

  • AfterAllExtensionPoint has been renamed to AfterAllCallback.

  • BeforeEachExtensionPoint has been renamed to BeforeEachCallback.

  • BeforeAllExtensionPoint has been renamed to BeforeAllCallback.

  • New BeforeTestExecutionCallback and AfterTestExecutionCallback extension APIs.

  • ExceptionHandlerExtensionPoint has been renamed to TestExecutionExceptionHandler.

  • Test exceptions are now supplied to extensions via the TestExtensionContext.

  • ExtensionContext.Store now supports type-safe variants of many of its methods.

  • ExtensionContext.getElement() now returns an Optional.

  • Namespace.of() has been renamed to Namespace.create().

  • TestInfo and ExtensionContext have new getTestClass() and getTestMethod() methods.

  • The getName() method has been removed from TestInfo and ExtensionContext in favor of retrieving a context specific name via the current test class or test method.

JUnit Vintage

  • The junit4 engine ID has been renamed to junit-vintage.

  • JUnit4TestEngine has been renamed to VintageTestEngine.

5.0.0-M2

Date of Release: July 23, 2016

Scope: Second milestone release of JUnit 5

Summary of Changes

This release is primarily a bugfix release for bugs discovered since 5.0.0-M1.

The following is a list of global changes. For details regarding changes specific to the Platform, Jupiter, and Vintage, consult the dedicated subsections below. For a complete list of all closed issues and pull requests for this release, consult the 5.0 M2 milestone page in the JUnit repository on GitHub.

  • The JUnit 5 Gradle build now runs properly on Microsoft Windows.

  • A continuous integration build against Microsoft Windows has been set up on AppVeyor.

JUnit Platform

Bug Fixes
  • Failures in containers — for example, @BeforeAll methods that throw exceptions — now fail the build when using the ConsoleLauncher or the JUnit Platform Gradle plugin.

  • The JUnit Platform Surefire Provider no longer silently ignores purely dynamic test classes — for example, test classes that only declare @TestFactory methods.

  • The junit-platform-console and junit-platform-console.bat shell scripts included in the junit-platform-console-<release version> TAR and ZIP distributions now properly refer to the ConsoleLauncher instead of the ConsoleRunner.

  • The TestExecutionSummary used by the ConsoleLauncher and the JUnit Platform Gradle plugin now includes the actual exception type for failures.

  • Classpath scanning is now safeguarded against exceptions encountered during class loading and processing — for example, when processing classes with malformed names. The underlying exception is swallowed and logged along with the offending file path. If the exception is a blacklisted exception such as an OutOfMemoryError, however, it will be rethrown.

Deprecations
  • Generic name-based discovery selectors (i.e., selectName() and selectNames()) in DiscoverySelectors have been deprecated in favor of the dedicated selectPackage(String), selectClass(String), and selectMethod(String) methods.

New Features
  • New selectMethod(String) method in DiscoverySelectors that supports selection of a fully qualified method name.

JUnit Jupiter

Bug Fixes
  • Extension implementations declared via @ExtendWith at the class-level and at the method-level will no longer be registered multiple times.

JUnit Vintage

No changes since 5.0.0-M1

5.0.0-M3

Date of Release: November 30, 2016

Scope: Third milestone release of JUnit 5 with a focus on JUnit 4 interoperability, additional discovery selectors, and documentation.

For a complete list of all closed issues and pull requests for this release, consult the 5.0 M3 milestone page in the JUnit repository on GitHub.

JUnit Platform

Bug Fixes
  • ColoredPrintingTestListener, which is used by the ConsoleLauncher, now outputs the actual exception type and its stack trace when printing an exception message.

  • Test classes in the default package are now picked up via classpath scanning when scanning classpath roots — for example, in conjunction with the JUnit Platform Gradle plugin when no explicit packages have been selected.

  • Classpath scanning no longer loads classes that are excluded by a class name filter.

  • Classpath scanning no longer attempts to load Java 9 module-info.class files.

Deprecations and Breaking Changes
  • ClasspathSelector has been renamed to ClasspathRootSelector to avoid confusion with ClasspathResourceSelector.

  • JavaPackageSource has been renamed to PackageSource to align with PackageSelector.

  • JavaClassSource has been renamed to ClassSource to align with ClassSelector.

  • JavaMethodSource has been renamed to MethodSource to align with MethodSelector.

  • PackageSource, ClassSource, and MethodSource now directly implement the TestSource interface instead of the JavaSource interface which has been removed.

  • Generic name-based discovery selectors (i.e., selectName() and selectNames()) in DiscoverySelectors have been deprecated in favor of the dedicated selectPackage(String), selectClass(String), and selectMethod(String) methods.

  • ClassFilter has been renamed to ClassNameFilter and now implements DiscoveryFilter<String> instead of DiscoveryFilter<Class<?>> so it can be applied before loading classes during classpath scanning.

  • ClassNameFilter.includeClassNamePattern is now deprecated in favor of ClassNameFilter.includeClassNamePatterns.

  • @IncludeClassNamePattern is now deprecated in favor of @IncludeClassNamePatterns.

  • The -p command-line option for configuring additional classpath entries for the ConsoleLauncher has been renamed to -cp in order to align with the option names for the standard java executable. In addition, a new --class-path alias has been introduced, while the existing --classpath command-line option remains unchanged.

  • The -a and --all command-line options for the ConsoleLauncher have been renamed to --scan-class-path.

  • The --xml-reports-dir command-line option for the ConsoleLauncher has been renamed to --reports-dir.

  • The -C, -D, and -r short command-line options for the ConsoleLauncher have been removed in favor of using their long equivalents --disable-ansi-colors, --hide-details, and --reports-dir respectively.

  • The ConsoleLauncher no longer supports passing non-option arguments. Please use the new explicit selector options to specify package, class, or method names instead. Alternatively, --scan-class-path now accepts an optional argument that can be used to select classpath entries to be scanned. Multiple classpath entries may be used by separating them using the system’s path separator (; on Windows, : on Unix).

  • LauncherDiscoveryRequestBuilder no longer accepts null values for selectors, filters, or maps of configuration parameters.

  • Filters for class name, engine IDs, and tags in the Gradle plugin configuration now need to be wrapped in a filters extension element (see Configuring Filters).

New Features
  • New selectUri(…​) methods in DiscoverySelectors for selecting URIs. A TestEngine can retrieve such values by querying registered instances of UriSelector.

  • New selectFile(…​) and selectDirectory(…​) methods in DiscoverySelectors for selecting files and directories in the file system. A TestEngine can retrieve such values by querying registered instances of FileSelector and DirectorySelector.

  • New selectClasspathResource(String) method in DiscoverySelectors for selecting classpath resources such as XML or JSON files by name, where the name is a /-separated path name for the resource within the current classpath. A TestEngine can retrieve such values by querying registered instances of ClasspathResourceSelector. Furthermore, a classpath resource can be made available as the TestSource of a TestIdentifier via the new ClasspathResourceSource.

  • The selectMethod(String) method in DiscoverySelectors now supports selection of a fully qualified method name for a method that accepts parameters — for example, "org.example.TestClass#testMethod(org.junit.jupiter.api.TestInfo)".

  • The TestExecutionSummary used by the ConsoleLauncher and the JUnit Platform Gradle plugin now includes statistics for all container events in addition to test events.

  • The TestExecutionSummary can now be used to get the list of all failures.

  • The ConsoleLauncher, the Gradle plugin, and the JUnitPlatform runner now use ^.*Tests?$ as the default pattern for class names to be included in the test run.

  • The Gradle plugin now allows to explicitly select which tests should be executed (see Configuring Selectors).

  • New @Testable annotation that TestEngine implementations can use to signal to IDEs and tooling vendors that the annotated or meta-annotated element is testable (i.e. that it can be executed as a test on the JUnit Platform).

  • Multiple regular expressions that are combined using OR semantics can now be passed to ClassNameFilter.includeClassNamePatterns.

  • Multiple regular expressions that are combined using OR semantics can now be passed via @IncludeClassNamePatterns to the JUnitPlatform runner.

  • Multiple regular expressions that are combined using OR semantics can now be passed to the JUnit Platform Gradle plugin (see Configuring Filters) and the ConsoleLauncher (see Options).

  • Package names can now be included or excluded using PackageNameFilter.includePackageNames or PackageNameFilter.excludePackageNames.

  • Package names can now be included or excluded using @IncludePackages and @ExcludePackages in combination with the JUnitPlatform runner.

  • Package names can now be included or excluded via a filter configuration to the JUnit Platform Gradle plugin (see Configuring Filters) and the ConsoleLauncher (see Options).

  • The junit-platform-console no longer has a mandatory dependency on JOpt Simple. Thus, it’s now possible to test custom code that uses a different version of that library.

  • Resolution of package selectors now also scans JAR files.

  • The Surefire provider now supports forking.

  • The Surefire provider now supports filtering by tags using one of the following parameters:

    • include: groups/includeTags

    • exclude: excludedGroups/excludeTags

  • The Surefire provider is now licensed under the Apache License v2.0.

JUnit Jupiter

Bug Fixes
  • @AfterEach methods are now executed with bottom-up semantics within a test class hierarchy.

  • DynamicTest.stream() now accepts a ThrowingConsumer instead of a conventional Consumer for its test executor, thereby allowing for custom streams of dynamic tests that may potentially throw checked exceptions.

  • Extensions registered at the test method level are now used when invoking @BeforeEach and @AfterEach methods for the corresponding test method.

  • The JupiterTestEngine now supports selection of test methods via their unique ID for methods that accept arrays or primitive types as parameters.

  • ExtensionContext.Store is now thread-safe.

Deprecations and Breaking Changes
  • The Executable functional interface has been relocated to a new dedicated org.junit.jupiter.api.function package.

  • Assertions.expectThrows() has been deprecated in favor of Assertions.assertThrows().

New Features and Improvements
  • Support for lazy and preemptive timeouts with lambda expressions in Assertions. See examples in AssertionsDemo and consult the org.junit.jupiter.Assertions Javadoc for further details.

  • New assertIterableEquals() assertion that checks that two Iterables are deeply equal (see Javadoc for details).

  • New variants of Assertions.assertAll() that accept streams of executables (i.e., Stream<Executable>).

  • Assertions.assertThrows() now returns the thrown exception.

  • @BeforeAll and @AfterAll may now be declared on static methods in interfaces.

  • The JUnit 4 Rules org.junit.rules.ExternalResource, org.junit.rules.Verifier, org.junit.rules.ExpectedException including subclasses are now supported in JUnit Jupiter to facilitate migration of JUnit 4 codebases.

JUnit Vintage

No changes since 5.0.0-M2

5.0.0-M4

Date of Release: April 1, 2017

Scope: Fourth milestone release of JUnit 5 with a focus on test templates, repeated tests, and parameterized tests.

For a complete list of all closed issues and pull requests for this release, consult the 5.0 M4 milestone page in the JUnit repository on GitHub.

JUnit Platform

Bug Fixes
  • The JUnit Platform Gradle plugin now adds its dependencies with a fixed version (same as the plugin version) instead of a dynamic versioning scheme (was 1.+) by default to ensure reproducible builds.

  • The JUnit Platform Gradle plugin now explicitly applies the Gradle built-in java plugin as it has an implicit dependency on it being applied.

  • All findMethods() implementations in ReflectionUtils no longer return synthetic methods. Shadowed override-equal methods are also no longer included in the results.

  • Introduced getLegacyReportingName() in TestIdentifier and TestDescriptor. This allows the JUnit Platform Gradle Plugin and the Surefire Provider to resolve the class and method names through getLegacyReportingName() instead of using the source location.

  • JAR files that contain spaces in their paths (%20) are now properly decoded before being used in classpath scanning routines.

  • Updated findNestedClasses() in ReflectionUtils so that searches for nested classes also return inherited nested classes (regardless of whether they are static or not).

Deprecations and Breaking Changes
  • All test suite annotations from the org.junit.platform.runner package have been moved to the org.junit.platform.suite.api package in the new junit-platform-suite-api module. This includes annotations such as @SelectClasses, @SelectPackages, etc.

  • Removed deprecated selectNames() name-based discovery selector from DiscoverySelectors in favor of the dedicated selectPackage(String), selectClass(String), and selectMethod(String) methods.

  • ClassNameFilter.includeClassNamePattern was removed; please use ClassNameFilter.includeClassNamePatterns instead.

  • @IncludeClassNamePattern has been removed; please use @IncludeClassNamePatterns instead.

  • The --hide-details option of the ConsoleLauncher is deprecated; use --details none instead.

  • The ZIP distribution containing the console launcher is no longer provided. It has been replaced by an executable standalone JAR distribution. For details, see the "New Features" section below.

  • The MethodSortOrder enum in ReflectionUtils has been renamed to HierarchyTraversalMode. Those affected should now use ReflectionSupport instead of ReflectionUtils.

  • The method execute(LauncherDiscoveryRequest launcherDiscoveryRequest) in Launcher has been deprecated and will be removed in milestone M5. Instead use the following new method that registers supplied TestExecutionListeners in addition to already registered listeners but only for the supplied LauncherDiscoveryRequest: execute(LauncherDiscoveryRequest launcherDiscoveryRequest, TestExecutionListener…​ listeners)

New Features and Improvements
  • Custom TestExecutionListener implementations can now be registered automatically via Java’s ServiceLoader mechanism.

  • New getGroupId(), getArtifactId(), and getVersion() default methods in the TestEngine API for debugging and reporting purposes. By default, package attributes (i.e., typically from JAR manifest attributes) are used to determine the artifact ID and version; whereas, the group ID is empty by default. Consult the Javadoc for TestEngine for details.

  • Logging information for discovered test engines has been enhanced to include the group ID, artifact ID, and version of each test engine if available via the getGroupId(), getArtifactId(), and getVersion() methods.

  • The --scan-classpath option of the ConsoleLauncher now allows to scan JAR files for tests when they are supplied as explicit arguments (see Options).

  • The new --details <Details> option of the ConsoleLauncher now allows to select an output details mode for when tests are executed. Use one of: none, flat, tree or verbose. If none is selected, then only the summary and test failures are shown (see Options).

  • The new --details-theme <Theme> option of the ConsoleLauncher now allows to select a theme for when tests are executed and printed as a tree. Use one of: ascii or unicode (see Options).

  • An executable junit-platform-console-standalone-1.0.0-SNAPSHOT.jar artifact containing the Jupiter and Vintage test engines with all dependencies is generated by the default build process, stored in junit-platform-console-standalone/build/libs, and published to Maven Central. It provides hassle-free usage of JUnit 5 in projects that manually manage their dependencies similar to the plain-old JAR known from JUnit 4.

  • New --exclude-classname (--N) option added to the ConsoleLauncher accepting a regular expression to exclude those classes whose fully qualified names match. When this option is repeated, all patterns will be combined using OR semantics.

  • New JUnit Platform support package org.junit.platform.commons.support that contains maintained utility methods for annotation, reflection, and classpath scanning tasks. TestEngine and Extension authors are encouraged to use these supported methods in order to align with the behavior of the JUnit Platform.

  • Squashed logic behind TestDescriptor.isTest() and TestDescriptor.isContainer() from two independent boolean properties into a single enumeration, namely TestDescriptor.Type. See next bullet point for details.

  • Introduced TestDescriptor.Type enumeration with TestDescriptor.getType() accessor defining all possible descriptor types. TestDescriptor.isTest() and TestDescriptor.isContainer() now delegate to TestDescriptor.Type constants.

  • Introduced TestDescriptor.prune() and TestDescriptor.pruneTree() which allow engine authors to customize what happens when pruning is triggered by the JUnit Platform.

  • TestIdentifier now uses the new TestDescriptor.Type enumeration to store the underlying type. It can be retrieved via the new TestIdentifier.getType() method. Furthermore, TestIdentifier.isTest() and TestIdentifier.isContainer() now delegate to TestDescriptor.Type constants.

JUnit Jupiter

Bug Fixes
  • Fixed bug that prevented discovery of two or more methods in the same class when selected via a method selector.

  • @Nested non-static test classes are now detected when declared in super classes.

  • The correct execution order of overridden @BeforeEach and @AfterEach methods is now enforced when declared at multiple levels within a class hierarchy. It’s now always super.before, this.before, this.test, this.after, and super.after, even if the compiler adds synthetic methods.

  • TestExecutionExceptionHandlers are now invoked in the opposite order in which they were registered, analogous to all other "after" extensions.

Deprecations and Breaking Changes
  • Removed deprecated Assertions.expectThrows() method in favor of Assertions.assertThrows().

  • ExtensionContext.Namespaces composed of the same parts but in a different order are no longer considered equal to each other.

New Features and Improvements
  • First-class support for parameterized tests via the new @ParameterizedTest annotation. See Parameterized Tests for details.

  • First-class support for repeated tests via the new @RepeatedTest annotation and RepetitionInfo API. See Repeated Tests for details.

  • Introduce @TestTemplate annotation and accompanying extension point TestTemplateInvocationContextProvider.

  • Assertions.assertThrows() now uses canonical names for exception types when generating assertion failure messages.

  • TestInstancePostProcessors registered on test methods are now invoked.

  • New variants of Assertions.fail: Assertions.fail(Throwable cause) and Assertions.fail(String message, Throwable cause).

  • New Assertions.assertLinesMatch() comparing lists of strings, featuring Object::equals and regular expression checks. assertLinesMatch() also provides a fast-forward mechanism to skip lines that are expected to change in each invocation — for example, duration, timestamps, stack traces, etc. Consult the JavaDoc for org.junit.jupiter.Assertions for details.

  • Extensions can now be registered automatically via Java’s ServiceLoader mechanism. See Automatic Extension Registration.

JUnit Vintage

Bug Fixes
  • Fixed bug that caused only the last failure of a test to be reported. For example, when using the ErrorCollector rule, only the last failed check was reported. Now, all failures are reported using an org.opentest4j.MultipleFailuresError.

5.0.0-M5

Date of Release:

Scope: Fifth milestone release of JUnit 5 with a focus on dynamic containers and minor API changes.

This is a milestone release and contains breaking changes. Please refer to the instructions above to use this version in a version of IntelliJ IDEA that bundles an older milestone release.

For a complete list of all closed issues and pull requests for this release, consult the 5.0 M5 milestone page in the JUnit repository on GitHub.

  • All published JAR artifacts now contain an Automatic-Module-Name manifest attribute whose value is used as the name of the automatic module defined by that JAR file when it is placed on the Java 9 module path.

Table 4. Automatic module names
JAR file Automatic-Module-Name

junit-jupiter-api-<VERSION>.jar

org.junit.jupiter.api

junit-jupiter-engine-<VERSION>.jar

org.junit.jupiter.engine

junit-jupiter-migrationsupport-<VERSION>.jar

org.junit.jupiter.migrationsupport

junit-jupiter-params-<VERSION>.jar

org.junit.jupiter.params

junit-platform-commons-<VERSION>.jar

org.junit.platform.commons

junit-platform-console-<VERSION>.jar

org.junit.platform.console

junit-platform-engine-<VERSION>.jar

org.junit.platform.engine

junit-platform-gradle-plugin-<VERSION>.jar

org.junit.platform.gradle.plugin

junit-platform-launcher-<VERSION>.jar

org.junit.platform.launcher

junit-platform-runner-<VERSION>.jar

org.junit.platform.runner

junit-platform-suite-api-<VERSION>.jar

org.junit.platform.suite.api

junit-platform-surefire-provider-<VERSION>.jar

org.junit.platform.surefire.provider

junit-vintage-engine-<VERSION>.jar

org.junit.vintage.engine

JUnit Platform

Bug Fixes
  • MethodSelector.getMethodParameterTypes() no longer returns null for parameter types if the selector is created via DiscoverySelectors without explicit parameter types. Specifically, if parameter types are not supplied and cannot be deduced, an empty string will be returned. Similarly, if parameter types are not explicitly supplied but can be deduced (e.g, via a supplied Method reference), getMethodParameterTypes() now returns a string containing the deduced parameter types.

  • Instead of throwing a NullPointerException in Details.TREE mode, the ConsoleLauncher now prints the corresponding throwable’s toString() representation as a fallback mechanism.

  • DefaultLauncher now catches and warns about exceptions generated by an engine in its discovery and execution phases. Other engines are processed normally.

  • UniqueId.Segment type and value strings are now partially URL encoded when the string representation of a unique ID is generated. All characters reserved by the active UniqueIdFormat syntax (e.g., [, :, ], and /) are encoded. The default parser has also been updated to decode such encoded segments.

Deprecations and Breaking Changes
  • The deprecated --hide-details option of the ConsoleLauncher has been removed; use --details none instead.

  • The following previously deprecated methods have been removed.

    • junit-platform-engine: Node.execute(EngineExecutionContext)

    • junit-platform-commons: ReflectionUtils.findAllClassesInClasspathRoot(Path, Predicate, Predicate)

  • The isLeaf() method of the org.junit.platform.engine.support.hierarchical.Node interface has been removed.

  • The default methods pruneTree(), and hasTests() have been removed from TestDescriptor.

New Features and Improvements
  • When using DiscoverySelectors to select a method by its fully qualified method name or by providing methodParameterTypes as a comma-separated string, it is now possible to describe array parameter types using source code syntax such as int[] for a primitive array and java.lang.String[] for an object array. Furthermore, it is now possible to describe multidimensional array types using either the JVM’s internal String representation (e.g., [[[I for int[][][], [[Ljava.lang.String; for java.lang.String[][], etc.) or source code syntax (e.g., boolean[][][], java.lang.Double[][], etc.).

  • The JUnit Platform Gradle plugin task junitPlatformTest can now be accessed directly during the configuration phase of a build.

  • When a TestEngine is discovered via Java’s ServiceLoader mechanism, an attempt will now be made to determine the location from which the engine class was loaded, and if the location URL is available, it will be logged at configuration-level.

  • The mayRegisterTests() method may be used to signal that a TestDescriptor will register dynamic tests during execution.

  • The TestPlan may now be queried for whether it containsTests(). This is used by the Surefire provider to decide if a class is a test class that should be executed.

  • The ENGINE enum constant was removed from TestDescriptor.Type. The default type of the EngineDescriptor is now TestDescriptor.Type.CONTAINER.

JUnit Jupiter

Bug Fixes
  • @ParameterizedTest arguments are no longer resolved for lifecycle methods and test class constructors to improve interoperability with regular and parameterized test methods with different parameter lists.

Deprecations and Breaking Changes
  • The migration support module is now named junit-jupiter-migrationsupport, without the dash - between migration and support.

  • In order to ensure the composability of all supported extension APIs in JUnit Jupiter, several methods in existing APIs have been renamed.

  • The arguments() method in the ArgumentsProvider API in the junit-jupiter-params module has been renamed to provideArguments().

  • The ObjectArrayArguments class in the junit-jupiter-params module has been removed; the functionality for creating an Arguments instance is now available via the Arguments.of(…​) static factory method.

  • The names property of @MethodSource has been renamed to value.

Table 5. Extension API Migration
Extension API Old Name New Name

ParameterResolver

supports()

supportsParameter()

ParameterResolver

resolve()

resolveParameter()

ContainerExecutionCondition

evaluate()

evaluateContainerExecutionCondition()

TestExecutionCondition

evaluate()

evaluateTestExecutionCondition()

TestTemplateInvocationContextProvider

supports()

supportsTestTemplate()

TestTemplateInvocationContextProvider

provide()

provideTestTemplateInvocationContexts()

New Features and Improvements
  • Assertions.assertAll() now tracks exceptions of any type (as opposed to only tracking exceptions of type AssertionError), unless the exception is a blacklisted exception in which case it will be immediately rethrown.

  • If a @ParameterizedTest accepts an array as an argument, the string representation of the array will now be converted to a human readable format when generating the display name for invocations of the parameterized test.

  • The @EnumSource now provides an enum constant selection mode that controls how the supplied names are interpreted. Supported modes include INCLUDE and EXCLUDE as well as regular expression pattern matching modes MATCH_ALL and MATCH_ANY.

  • Extensions may now share state across top-level test classes by using the Store of the newly introduced engine-level ExtensionContext.

  • Argument providing methods referenced using @MethodSource may now return instances of DoubleStream, IntStream, and LongStream directly.

  • @TestFactory now supports arbitrarily nested dynamic containers. See DynamicContainer and abstract base class DynamicNode for details.

JUnit Vintage

Bug Fixes
  • The VintageTestEngine no longer filters out test classes declared as static member classes, since they are valid JUnit 4 test classes.

  • The VintageTestEngine no longer attempts to execute abstract classes as test classes. Instead, a warning is now logged stating that such classes are excluded.