Solve issue #207: Ask for concrete subclass when running tests in abstract class

- Implemented `SearchTools.findConcreteSubclasses(IType)` to retrieve non-abstract implementations of a type.
- Enhanced `RunTestsActionExecutor` to automatically resolve or prompt for concrete subclasses when test execution is triggered from an abstract class or its CUT.
- Added "All concrete subclasses" option to the selection dialog.
- Updated `JUnitTestSelectionLaunchConfigurationDelegate` to support granular `IMember` execution (types or methods).
- Added JUnit tests for subclass resolution logic.
- Enhanced test infrastructure to support interface definitions in `@Project` annotations.

Co-authored-by: RoiSoleil <3462260+RoiSoleil@users.noreply.github.com>

Author: google-labs-jules[bot]

org.moreunit.plugin/src/org/moreunit/handler/RunTestsActionExecutor.java

@@ -13,19 +13,27 @@
 
 import static org.moreunit.elements.CorrespondingMemberRequest.newCorrespondingMemberRequest;
 
+import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.Set;
 
 import org.eclipse.core.resources.IFile;
 import org.eclipse.core.runtime.NullProgressMonitor;
+import org.eclipse.jdt.core.Flags;
 import org.eclipse.jdt.core.ICompilationUnit;
 import org.eclipse.jdt.core.IJavaElement;
 import org.eclipse.jdt.core.IJavaProject;
 import org.eclipse.jdt.core.IMember;
 import org.eclipse.jdt.core.IMethod;
 import org.eclipse.jdt.core.IType;
 import org.eclipse.jdt.core.JavaCore;
+import org.eclipse.jdt.core.JavaModelException;
 import org.eclipse.jdt.internal.ui.javaeditor.EditorUtility;
+import org.eclipse.swt.graphics.Image;
+import org.eclipse.swt.widgets.Display;
 import org.eclipse.ui.IEditorPart;
 import org.moreunit.actions.RunTestAction;
 import org.moreunit.actions.RunTestFromCompilationUnitAction;
@@ -42,7 +50,12 @@
 import org.moreunit.launch.TestLauncher;
 import org.moreunit.preferences.Preferences;
 import org.moreunit.preferences.Preferences.MethodSearchMode;
+import org.moreunit.ui.ChooseDialog;
+import org.moreunit.ui.MemberContentProvider;
+import org.moreunit.ui.TreeActionElement;
 import org.moreunit.util.FeatureDetector;
+import org.moreunit.util.MemberJumpHistory;
+import org.moreunit.util.SearchTools;
 
 /**
  * Executes the actions "Run test(s)" launched from the handlers:<br>
@@ -134,10 +147,56 @@ private void executeRunAllTestsAction(ICompilationUnit compilationUnit, String l
             {
                 testCases.add(selectedJavaType);
             }
-            return testCases;
+            return resolveAbstractTestCases(testCases);
         }, testCases -> runTests(testCases, launchMode));
     }
 
+    private Collection<IType> resolveAbstractTestCases(Collection<IType> testCases)
+    {
+        Collection<IType> resolvedTestCases = new LinkedHashSet<>();
+        for (IType testCase : testCases)
+        {
+            resolvedTestCases.addAll(resolveAbstractTestCase(testCase));
+        }
+        return resolvedTestCases;
+    }
+
+    private Collection<IType> resolveAbstractTestCase(IType testCase)
+    {
+        try
+        {
+            if(! Flags.isAbstract(testCase.getFlags()))
+            {
+                return Collections.singleton(testCase);
+            }
+
+            Collection<IType> concreteSubclasses = SearchTools.findConcreteSubclasses(testCase);
+            if(concreteSubclasses.isEmpty())
+            {
+                return Collections.singleton(testCase);
+            }
+            if(concreteSubclasses.size() == 1)
+            {
+                return Collections.singleton(concreteSubclasses.iterator().next());
+            }
+
+            Collection<IType> choice = chooseSubclasses(testCase, concreteSubclasses);
+            if(choice != null && ! choice.isEmpty())
+            {
+                for (IType type : choice)
+                {
+                    MemberJumpHistory.getInstance().registerJump(testCase, type);
+                }
+                return choice;
+            }
+        }
+        catch (JavaModelException e)
+        {
+            // ignore and return original
+        }
+        return Collections.singleton(testCase);
+    }
+
     private void saveIfNeeded(ICompilationUnit compilationUnit)
     {
         IEditorPart editorPart = EditorUtility.isOpenInEditor(compilationUnit);
@@ -194,10 +253,139 @@ private void executeRunTestsOfSelectedMemberAction(IMethod methodFromEditor, ICo
             {
                 testElements.add(getTestElementFromTestCase(methodFromEditor, selectedJavaType));
             }
-            return testElements;
+            return resolveAbstractTestElements(testElements);
         }, testElements -> runTests(testElements, launchMode));
     }
 
+    private Collection<IMember> resolveAbstractTestElements(Collection<IMember> testElements)
+    {
+        Collection<IMember> resolvedTestElements = new LinkedHashSet<>();
+        for (IMember testElement : testElements)
+        {
+            resolvedTestElements.addAll(resolveAbstractTestElement(testElement));
+        }
+        return resolvedTestElements;
+    }
+
+    private Collection<IMember> resolveAbstractTestElement(IMember testElement)
+    {
+        IType type = testElement instanceof IType ? (IType) testElement : testElement.getDeclaringType();
+        try
+        {
+            if(! Flags.isAbstract(type.getFlags()))
+            {
+                return Collections.singleton(testElement);
+            }
+
+            Collection<IType> concreteSubclasses = SearchTools.findConcreteSubclasses(type);
+            if(concreteSubclasses.isEmpty())
+            {
+                return Collections.singleton(testElement);
+            }
+            if(concreteSubclasses.size() == 1)
+            {
+                return Collections.singleton(substituteType(testElement, concreteSubclasses.iterator().next()));
+            }
+
+            Collection<IType> chosenSubclasses = chooseSubclasses(type, concreteSubclasses);
+            if(chosenSubclasses != null && ! chosenSubclasses.isEmpty())
+            {
+                Collection<IMember> resolvedElements = new ArrayList<>();
+                for (IType chosenSubclass : chosenSubclasses)
+                {
+                    MemberJumpHistory.getInstance().registerJump(testElement, chosenSubclass);
+                    resolvedElements.add(substituteType(testElement, chosenSubclass));
+                }
+                return resolvedElements;
+            }
+        }
+        catch (JavaModelException e)
+        {
+            // ignore and return original
+        }
+        return Collections.singleton(testElement);
+    }
+
+    private IMember substituteType(IMember testElement, IType newType)
+    {
+        if(testElement instanceof IType)
+        {
+            return newType;
+        }
+        // It's a method. We return the method with the same name from the new type if it exists.
+        // If not, we still return the method from the abstract class, but the launcher should handle it.
+        // Actually, JDT's JUnit launcher handles methods from superclasses correctly if the target type is the subclass.
+        // But for clarity, let's see if we can find the method in the subclass.
+        IMethod method = (IMethod) testElement;
+        IMethod subclassMethod = newType.getMethod(method.getElementName(), method.getParameterTypes());
+        if(subclassMethod.exists())
+        {
+            return subclassMethod;
+        }
+        return method;
+    }
+
+    private Collection<IType> chooseSubclasses(IType abstractType, Collection<IType> concreteSubclasses)
+    {
+        IMember defaultSelection = MemberJumpHistory.getInstance().getLastCorrespondingJumpMember(abstractType);
+        if(! concreteSubclasses.contains(defaultSelection))
+        {
+            defaultSelection = null;
+        }
+
+        MemberContentProvider contentProvider = new MemberContentProvider(concreteSubclasses, (IType) defaultSelection);
+        contentProvider.withAction(new AllSubclassesAction(concreteSubclasses));
+
+        String promptText = "Choose concrete subclass for " + abstractType.getElementName();
+        return Display.getDefault().syncCall(() -> {
+            ChooseDialog<Object> dialog = new ChooseDialog<>(promptText, contentProvider);
+            Object choice = dialog.getChoice();
+            if(choice instanceof Collection)
+            {
+                return (Collection<IType>) choice;
+            }
+            if(choice instanceof IType)
+            {
+                return Collections.singleton((IType) choice);
+            }
+            return null;
+        });
+    }
+
+    private static class AllSubclassesAction implements TreeActionElement<Collection<IType>>
+    {
+        private final Collection<IType> concreteSubclasses;
+
+        public AllSubclassesAction(Collection<IType> concreteSubclasses)
+        {
+            this.concreteSubclasses = concreteSubclasses;
+        }
+
+        @Override
+        public boolean provideElement()
+        {
+            return true;
+        }
+
+        @Override
+        public Collection<IType> execute()
+        {
+            return concreteSubclasses;
+        }
+
+        @Override
+        public String getText()
+        {
+            return "All concrete subclasses";
+        }
+
+        @Override
+        public Image getImage()
+        {
+            return null;
+        }
+    }
+
     /**
      * Returns the test method that is selected in editor if any, otherwise
      * returns the test case.

org.moreunit.plugin/src/org/moreunit/launch/JUnitTestSelectionLaunchConfigurationDelegate.java

@@ -18,26 +18,16 @@
  */
 class JUnitTestSelectionLaunchConfigurationDelegate extends JUnitLaunchConfigurationDelegate
 {
-    private final Collection<IType> testCasesToRun;
+    private final Collection<IMember> testMembersToRun;
 
     JUnitTestSelectionLaunchConfigurationDelegate(Collection< ? extends IMember> testsToRun)
     {
-        testCasesToRun = getTestCases(testsToRun);
-    }
-
-    private Collection<IType> getTestCases(Collection< ? extends IMember> testsToRun)
-    {
-        Collection<IType> testCases = new LinkedHashSet<IType>();
-        for (IMember testMember : testsToRun)
-        {
-            testCases.add(testMember instanceof IType ? (IType) testMember : testMember.getDeclaringType());
-        }
-        return testCases;
+        testMembersToRun = new LinkedHashSet<>(testsToRun);
     }
 
     @Override
     protected IMember[] evaluateTests(ILaunchConfiguration configuration, IProgressMonitor monitor) throws CoreException
     {
-        return testCasesToRun.toArray(new IMember[0]);
+        return testMembersToRun.toArray(new IMember[0]);
     }
 }

org.moreunit.plugin/src/org/moreunit/util/SearchTools.java

@@ -9,7 +9,11 @@
 import java.util.TreeSet;
 
 import org.eclipse.core.runtime.CoreException;
+import org.eclipse.core.runtime.NullProgressMonitor;
+import org.eclipse.jdt.core.Flags;
 import org.eclipse.jdt.core.IType;
+import org.eclipse.jdt.core.ITypeHierarchy;
+import org.eclipse.jdt.core.JavaModelException;
 import org.eclipse.jdt.core.search.IJavaSearchScope;
 import org.eclipse.jdt.core.search.SearchEngine;
 import org.eclipse.jdt.core.search.SearchMatch;
@@ -31,6 +35,21 @@ public static Set<IType> searchFor(Collection<String> typeNamePatterns, IJavaSea
         return search(createSearchPattern(typeNamePatterns, TYPE, DECLARATIONS, R_PATTERN_MATCH), scope);
     }
 
+    public static Set<IType> findConcreteSubclasses(IType type) throws JavaModelException
+    {
+        Set<IType> concreteSubclasses = new LinkedHashSet<>();
+        ITypeHierarchy hierarchy = type.newTypeHierarchy(new NullProgressMonitor());
+        IType[] subtypes = hierarchy.getAllSubtypes(type);
+        for (IType subtype : subtypes)
+        {
+            if(! Flags.isAbstract(subtype.getFlags()) && ! Flags.isInterface(subtype.getFlags()))
+            {
+                concreteSubclasses.add(subtype);
+            }
+        }
+        return concreteSubclasses;
+    }
+
     private static Set<IType> search(SearchPattern pattern, IJavaSearchScope scope) throws CoreException
     {
         SearchParticipant[] participants = new SearchParticipant[] { SearchEngine.getDefaultSearchParticipant() };

org.moreunit.test.dependencies/src/org/moreunit/test/context/AnnotationConfigExtractor.java

@@ -265,6 +265,10 @@ private Collection<JavaType> splitTypes(String classes)
                 {
                     types.add(JavaType.newEnum(packageName, typeDef.substring(5)));
                 }
+                else if(typeDef.startsWith("interface "))
+                {
+                    types.add(JavaType.newInterface(packageName, typeDef.substring(10)));
+                }
                 else if(typeDef.startsWith("class "))
                 {
                     types.add(JavaType.newClass(packageName, typeDef.substring(6)));

org.moreunit.test.dependencies/src/org/moreunit/test/workspace/JavaType.java

@@ -27,6 +27,11 @@ public static JavaType newClass(String packageName, String typeName)
         return new JavaType(JavaTypeKind.CLASS, packageName, typeName);
     }
 
+    public static JavaType newInterface(String packageName, String typeName)
+    {
+        return new JavaType(JavaTypeKind.INTERFACE, packageName, typeName);
+    }
+
     @Override
     public int hashCode()
     {

org.moreunit.test.dependencies/src/org/moreunit/test/workspace/JavaTypeKind.java

@@ -2,7 +2,7 @@
 
 public enum JavaTypeKind
 {
-    CLASS, ENUM;
+    CLASS, ENUM, INTERFACE;
 
     String toJavaCode()
     {

org.moreunit.test.dependencies/src/org/moreunit/test/workspace/SourceFolderHandler.java

@@ -67,6 +67,10 @@ public TypeHandler createType(JavaType javaType)
             {
                 type = WorkspaceHelper.createJavaClass(packageFragment, javaType.typeName);
             }
+            else if(javaType.typeKind == JavaTypeKind.INTERFACE)
+            {
+                type = WorkspaceHelper.createJavaInterface(packageFragment, javaType.typeName);
+            }
             else
             {
                 type = WorkspaceHelper.createJavaEnum(packageFragment, javaType.typeName);
@@ -90,6 +94,11 @@ public TypeHandler createEnum(String fullyQualifiedTypeName)
         return createType(JavaTypeKind.ENUM, fullyQualifiedTypeName);
     }
 
+    public TypeHandler createInterface(String fullyQualifiedTypeName)
+    {
+        return createType(JavaTypeKind.INTERFACE, fullyQualifiedTypeName);
+    }
+
     public CompilationUnitHandler createCompilationUnit(String fullyQualifiedTypeName, String contents)
     {
         try
@@ -113,6 +122,10 @@ private TypeHandler createType(JavaTypeKind typeKind, String fullyQualifiedTypeN
         {
             return createType(JavaType.newEnum(name.packageName, name.typeName));
         }
+        if(typeKind == JavaTypeKind.INTERFACE)
+        {
+            return createType(JavaType.newInterface(name.packageName, name.typeName));
+        }
         return createType(JavaType.newClass(name.packageName, name.typeName));
     }
 

org.moreunit.test.dependencies/src/org/moreunit/test/workspace/WorkspaceHelper.java

@@ -189,6 +189,11 @@ public static IType createJavaEnum(IPackageFragment packageFragment, String java
         return createJavaType(packageFragment, javaClassName, JavaTypeKind.ENUM);
     }
 
+    public static IType createJavaInterface(IPackageFragment packageFragment, String javaClassName) throws JavaModelException
+    {
+        return createJavaType(packageFragment, javaClassName, JavaTypeKind.INTERFACE);
+    }
+
     private static IType createJavaType(IPackageFragment packageFragment, String javaClassName, JavaTypeKind type) throws JavaModelException
     {
         String sourceCode = String.format("%s%s%s", getPackageDeclarationString(packageFragment), NEW_LINE, getTypeDeclarationString(type, javaClassName));