Module org.junit.platform.launcher
Package org.junit.platform.launcher.listeners

Class UniqueIdTrackingListener

java.lang.Object
org.junit.platform.launcher.listeners.UniqueIdTrackingListener
All Implemented Interfaces:
TestExecutionListener
@API(status=EXPERIMENTAL, since="1.8") public class UniqueIdTrackingListener extends Object implements TestExecutionListener
UniqueIdTrackingListener is a TestExecutionListener that tracks the unique IDs of all tests that were executed during the execution of the TestPlan and generates a file containing the unique IDs once execution of the TestPlan has finished.

Tests are tracked regardless of their TestExecutionResult or whether they were skipped, and the unique IDs are written to an output file, one ID per line, encoding using UTF-8.

The output file can be used to execute the same set of tests again without having to query the user configuration for the test plan and without having to perform test discovery again. This can be useful for test environments such as within a native image — for example, a GraalVM native image — in order to rerun the exact same tests from a standard JVM test run within a native image.

Configuration and Defaults

The OUTPUT_DIR is the directory in which this listener generates the output file. The exact path of the generated file is OUTPUT_DIR/OUTPUT_FILE_PREFIX-<random number>.txt, where <random number> is a pseudo-random number. The inclusion of a random number in the file name ensures that multiple concurrently executing test plans do not overwrite each other's results.

The value of the OUTPUT_FILE_PREFIX defaults to DEFAULT_OUTPUT_FILE_PREFIX, but a custom prefix can be set via the OUTPUT_FILE_PREFIX_PROPERTY_NAME configuration property.

The OUTPUT_DIR can be set to a custom directory via the OUTPUT_DIR_PROPERTY_NAME configuration property. Otherwise the following algorithm is used to select a default output directory.

  • If the current working directory of the Java process contains a file named pom.xml, the output directory will be ./target, following the conventions of Maven.
  • If the current working directory of the Java process contains a file with the extension .gradle or .gradle.kts, the output directory will be ./build, following the conventions of Gradle.
  • Otherwise, the current working directory of the Java process will be used as the output directory.

For example, in a project using Gradle as the build tool, the file generated by this listener would be ./build/junit-platform-unique-ids-<random number>.txt by default.

Configuration properties can be set via JVM system properties, via a junit-platform.properties file in the root of the classpath, or as JUnit Platform configuration parameters.

Since:
1.8

  • Field Details

    • LISTENER_ENABLED_PROPERTY_NAME

      public static final String LISTENER_ENABLED_PROPERTY_NAME
      Property name used to enable the UniqueIdTrackingListener: "junit.platform.listeners.uid.tracking.enabled"

      The UniqueIdTrackingListener is registered automatically via Java's ServiceLoader mechanism but disabled by default.

      Set the value of this property to true to enable this listener.

      See Also:
      Constant Field Values

    • OUTPUT_DIR_PROPERTY_NAME

      public static final String OUTPUT_DIR_PROPERTY_NAME
      Property name used to set the path to the output directory for the file generated by the UniqueIdTrackingListener: "junit.platform.listeners.uid.tracking.output.dir"

      For details on the default output directory, see the class-level Javadoc.

      See Also:
      Constant Field Values

    • OUTPUT_FILE_PREFIX_PROPERTY_NAME

      public static final String OUTPUT_FILE_PREFIX_PROPERTY_NAME
      Property name used to set the prefix for the name of the file generated by the UniqueIdTrackingListener: "junit.platform.listeners.uid.tracking.output.file.prefix"

      Defaults to DEFAULT_OUTPUT_FILE_PREFIX.

      See Also:
      Constant Field Values

    • DEFAULT_OUTPUT_FILE_PREFIX

      public static final String DEFAULT_OUTPUT_FILE_PREFIX
      The default prefix for the name of the file generated by the UniqueIdTrackingListener: "junit-platform-unique-ids"
      See Also:
      OUTPUT_FILE_PREFIX_PROPERTY_NAME, Constant Field Values

  • Constructor Details

    • UniqueIdTrackingListener

      public UniqueIdTrackingListener()

  • Method Details

    • testPlanExecutionStarted

      public void testPlanExecutionStarted​(TestPlan testPlan)
      Description copied from interface: TestExecutionListener
      Called when the execution of the TestPlan has started, before any test has been executed.
      Specified by:
      testPlanExecutionStarted in interface TestExecutionListener
      Parameters:
      testPlan - describes the tree of tests about to be executed

    • executionSkipped

      public void executionSkipped​(TestIdentifier testIdentifier, String reason)
      Description copied from interface: TestExecutionListener
      Called when the execution of a leaf or subtree of the TestPlan has been skipped.

      The TestIdentifier may represent a test or a container. In the case of a container, no listener methods will be called for any of its descendants.

      A skipped test or subtree of tests will never be reported as started or finished.

      Specified by:
      executionSkipped in interface TestExecutionListener
      Parameters:
      testIdentifier - the identifier of the skipped test or container
      reason - a human-readable message describing why the execution has been skipped

    • executionFinished

      public void executionFinished​(TestIdentifier testIdentifier, TestExecutionResult testExecutionResult)
      Description copied from interface: TestExecutionListener
      Called when the execution of a leaf or subtree of the TestPlan has finished, regardless of the outcome.

      The TestIdentifier may represent a test or a container.

      This method will only be called if the test or container has not been skipped.

      This method will be called for a container TestIdentifier after all of its children have been skipped or have finished.

      The TestExecutionResult describes the result of the execution for the supplied TestIdentifier. The result does not include or aggregate the results of its children. For example, a container with a failing test will be reported as SUCCESSFUL even if one or more of its children are reported as FAILED.

      Specified by:
      executionFinished in interface TestExecutionListener
      Parameters:
      testIdentifier - the identifier of the finished test or container
      testExecutionResult - the (unaggregated) result of the execution for the supplied TestIdentifier
      See Also:
      TestExecutionResult

    • testPlanExecutionFinished

      public void testPlanExecutionFinished​(TestPlan testPlan)
      Description copied from interface: TestExecutionListener
      Called when the execution of the TestPlan has finished, after all tests have been executed.
      Specified by:
      testPlanExecutionFinished in interface TestExecutionListener
      Parameters:
      testPlan - describes the tree of tests that have been executed