package org.junit.tests.experimental.theories.runner;
   
   import static org.junit.Assert.assertEquals;
   import static org.junit.tests.experimental.theories.TheoryTestUtils.potentialAssignments;
   
   import java.util.ArrayList;
   import java.util.Arrays;
   import java.util.List;
   
  import org.junit.Rule;
  import org.junit.Test;
  import org.junit.experimental.theories.ParameterSignature;
  import org.junit.experimental.theories.ParameterSupplier;
  import org.junit.experimental.theories.ParametersSuppliedBy;
  import org.junit.experimental.theories.PotentialAssignment;
  import org.junit.experimental.theories.Theories;
  import org.junit.experimental.theories.Theory;
  import org.junit.rules.ExpectedException;
  import org.junit.runner.RunWith;
  import org.junit.runners.model.InitializationError;
  import org.junit.runners.model.TestClass;
  
  public class WithParameterSupplier {
      
      @Rule
      public ExpectedException expected = ExpectedException.none();
  
      private static class SimplePotentialAssignment extends PotentialAssignment {
          private String description;
          private Object value;
  
          public SimplePotentialAssignment(Object value, String description) {
              this.value = value;
              this.description = description;
          }
  
          @Override
          public Object getValue() throws CouldNotGenerateValueException {
              return value;
          }
  
          @Override
          public String getDescription() throws CouldNotGenerateValueException {
              return description;
          }
      }
  
      private static final List<String> DATAPOINTS = Arrays.asList("qwe", "asd");
  
      public static class SimpleSupplier extends ParameterSupplier {
  
          @Override
          public List<PotentialAssignment> getValueSources(ParameterSignature sig) {
              List<PotentialAssignment> assignments = new ArrayList<PotentialAssignment>();
  
              for (String datapoint : DATAPOINTS) {
                  assignments.add(new SimplePotentialAssignment(datapoint,
                          datapoint));
              }
  
              return assignments;
          }
  
      }
  
      @RunWith(Theories.class)
      public static class TestClassUsingParameterSupplier {
  
          @Theory
          public void theoryMethod(@ParametersSuppliedBy(SimpleSupplier.class) String param) {
          }
  
      }
  
      @Test
      public void shouldPickUpDataPointsFromParameterSupplier() throws Throwable {
          List<PotentialAssignment> assignments = potentialAssignments(TestClassUsingParameterSupplier.class
                  .getMethod("theoryMethod", String.class));
  
          assertEquals(2, assignments.size());
          assertEquals(DATAPOINTS.get(0), assignments.get(0).getValue());
          assertEquals(DATAPOINTS.get(1), assignments.get(1).getValue());
      }
      
      public static class SupplierWithUnknownConstructor extends ParameterSupplier {
          
          public SupplierWithUnknownConstructor(String param) {
          }
  
          @Override
          public List<PotentialAssignment> getValueSources(ParameterSignature sig) {
              return null;
          }
  
      }
  
      @RunWith(Theories.class)
      public static class TestClassUsingSupplierWithUnknownConstructor {
  
         @Theory
         public void theory(@ParametersSuppliedBy(SupplierWithUnknownConstructor.class) String param) {
         }
 
     }
     
     @Test
     public void shouldRejectSuppliersWithUnknownConstructors() throws Exception {
         expected.expect(InitializationError.class);
         new Theories(TestClassUsingSupplierWithUnknownConstructor.class);
     }
     
     public static class SupplierWithTwoConstructors extends ParameterSupplier {
         
         public SupplierWithTwoConstructors(String param) {
         }
 
         @Override
         public List<PotentialAssignment> getValueSources(ParameterSignature sig) {
             return null;
         }
 
     }
 
     @RunWith(Theories.class)
     public static class TestClassUsingSupplierWithTwoConstructors {
 
         @Theory
         public void theory(@ParametersSuppliedBy(SupplierWithTwoConstructors.class) String param) {
         }
 
     }
     
     @Test
     public void shouldRejectSuppliersWithTwoConstructors() throws Exception {
         expected.expect(InitializationError.class);
         new Theories(TestClassUsingSupplierWithTwoConstructors.class);
     }
     
     public static class SupplierWithTestClassConstructor extends ParameterSupplier {
         
         public SupplierWithTestClassConstructor(TestClass param) {
         }
 
         @Override
         public List<PotentialAssignment> getValueSources(ParameterSignature sig) {
             return null;
         }
 
     }
 
     @RunWith(Theories.class)
     public static class TestClassUsingSupplierWithTestClassConstructor {
 
         @Theory
         public void theory(@ParametersSuppliedBy(SupplierWithTestClassConstructor.class) String param) {
         }
 
     }
     
     @Test
     public void shouldAcceptSuppliersWithTestClassConstructor() throws Exception {
         new Theories(TestClassUsingSupplierWithTestClassConstructor.class);
     }
 
 }