Fixes junit-team#1189: JUnit4TestAdapter blocks JUnit-3-style suites …

…that are included via @RunWith(Suite.class)

src/main/java/junit/framework/JUnit4TestAdapter.java

@@ -13,6 +13,16 @@
 import org.junit.runner.manipulation.Sortable;
 import org.junit.runner.manipulation.Sorter;
 
+/**
+ * The JUnit4TestAdapter enables running JUnit-4-style tests using a JUnit-3-style test runner.
+ * <p>
+ * To use it, add the following to a test class:
+ * <pre>
+      public static Test suite() {
+        return new JUnit4TestAdapter(<em>YourJUnit4TestClass</em>.class);
+      }
+</pre>
+ */
 public class JUnit4TestAdapter implements Test, Filterable, Sortable, Describable {
     private final Class<?> fNewTestClass;
 

src/main/java/org/junit/internal/builders/AllDefaultPossibilitiesBuilder.java

@@ -40,7 +40,10 @@ protected JUnit3Builder junit3Builder() {
     }
 
     protected AnnotatedBuilder annotatedBuilder() {
-        return new AnnotatedBuilder(this);
+        // For compatibility with Request#classes(...) and the Suite runner,
+        // deeper nesting levels always need to support suite() methods:
+        RunnerBuilder suiteBuilder = canUseSuiteMethod ? this : new AllDefaultPossibilitiesBuilder(true);
+        return new AnnotatedBuilder(suiteBuilder);
     }
 
     protected IgnoredBuilder ignoredBuilder() {

src/test/java/org/junit/tests/AllTests.java

@@ -18,13 +18,13 @@
 import org.junit.runner.notification.ConcurrentRunNotifierTest;
 import org.junit.runner.notification.RunNotifierTest;
 import org.junit.runner.notification.SynchronizedRunListenerTest;
-import org.junit.runners.parameterized.BlockJUnit4ClassRunnerWithParametersTest;
 import org.junit.runners.CustomBlockJUnit4ClassRunnerTest;
 import org.junit.runners.Suite;
 import org.junit.runners.Suite.SuiteClasses;
 import org.junit.runners.model.FrameworkFieldTest;
 import org.junit.runners.model.FrameworkMethodTest;
 import org.junit.runners.model.TestClassTest;
+import org.junit.runners.parameterized.BlockJUnit4ClassRunnerWithParametersTest;
 import org.junit.runners.parameterized.ParameterizedNamesTest;
 import org.junit.runners.parameterized.TestWithParametersTest;
 import org.junit.tests.assertion.AssertionTest;
@@ -82,6 +82,7 @@
 import org.junit.tests.junit3compatibility.ForwardCompatibilityTest;
 import org.junit.tests.junit3compatibility.InitializationErrorForwardCompatibilityTest;
 import org.junit.tests.junit3compatibility.JUnit38ClassRunnerTest;
+import org.junit.tests.junit3compatibility.JUnit4TestAdapterTest;
 import org.junit.tests.junit3compatibility.OldTestClassAdaptingListenerTest;
 import org.junit.tests.junit3compatibility.OldTests;
 import org.junit.tests.junit3compatibility.SuiteMethodTest;
@@ -157,6 +158,7 @@
         UserStopTest.class,
         SortableTest.class,
         JUnit38ClassRunnerTest.class,
+        JUnit4TestAdapterTest.class,
         SystemExitTest.class,
         JUnitCoreReturnsCorrectExitCodeTest.class,
         SuiteMethodTest.class,

src/test/java/org/junit/tests/junit3compatibility/JUnit4TestAdapterTest.java

@@ -0,0 +1,82 @@
+package org.junit.tests.junit3compatibility;
+
+import static org.junit.Assert.assertEquals;
+
+import java.util.Collections;
+
+import junit.framework.JUnit4TestAdapter;
+import junit.framework.TestCase;
+import junit.framework.TestResult;
+import junit.framework.TestSuite;
+import org.junit.Test;
+import org.junit.runner.JUnitCore;
+import org.junit.runner.Result;
+import org.junit.runner.RunWith;
+import org.junit.runners.Suite;
+
+public class JUnit4TestAdapterTest {
+
+    private static void doTest(Class<?> clazz) {
+        // JUnit 4 runner:
+        Result result = JUnitCore.runClasses(clazz);
+        assertEquals(1, result.getRunCount());
+        assertEquals(0, result.getFailureCount());
+        assertEquals(0, result.getIgnoreCount());
+
+        // JUnit 3 runner:
+        TestResult testResult = new TestResult();
+        new JUnit4TestAdapter(clazz).run(testResult);
+        assertEquals(1, testResult.runCount());
+        assertEquals(0, testResult.failureCount());
+        assertEquals(Collections.emptyList(), Collections.list(testResult.errors()));
+    }
+
+    public static class Test4 {
+        @Test
+        public void pass() throws Exception {
+            //pass
+        }
+    }
+
+    @RunWith(Suite.class)
+    @Suite.SuiteClasses(Test4.class)
+    public static class TestSuiteFor4 {
+    }
+
+    @Test
+    public void testJUnit4Suite() {
+        doTest(TestSuiteFor4.class);
+    }
+
+    public static class Test3 extends TestCase {
+        public void testPass() throws Exception {
+            //pass
+        }
+    }
+
+    @RunWith(Suite.class)
+    @Suite.SuiteClasses(Test3.class)
+    public static class TestSuiteFor3 {
+    }
+
+    @Test
+    public void testJUnit3Suite() {
+        doTest(TestSuiteFor3.class);
+    }
+
+    public static class TestSuite3 {
+        public static junit.framework.Test suite() {
+            return new TestSuite(Test3.class);
+        }
+    }
+
+    @RunWith(Suite.class)
+    @Suite.SuiteClasses(TestSuite3.class)
+    public static class TestSuite4ForTestSuite3 {
+    }
+
+    @Test
+    public void testJUnit4SuiteThatContainsJUnit3SuiteClass() {
+        doTest(TestSuite4ForTestSuite3.class);
+    }
+}