[eclipse/xtext#1851] More tests for the tests

see eclipse/xtext#1851

org.eclipse.xtext.testing/src/org/eclipse/xtext/testing/extensions/InjectionExtension.java

@@ -57,18 +57,26 @@ public class InjectionExtension implements BeforeEachCallback, AfterEachCallback
 	 * @since 2.24
 	 */
 	protected static class RegistryReset implements CloseableResource {
-		protected IRegistryConfigurator resetter;
+		protected final IRegistryConfigurator resetter;
+		protected boolean didSetup = false;
 
 		public RegistryReset(IRegistryConfigurator resetter) {
 			this.resetter = resetter;
 			resetter.setupRegistry();
 		}
+		
+		public void setup() {
+			if (!didSetup) {
+				didSetup = true;
+				resetter.setupRegistry();
+			}
+		}
 
 		@Override
 		public void close() throws Throwable {
-			if (resetter != null) {
+			if (didSetup) {
 				resetter.restoreRegistry();
-				resetter = null;
+				didSetup = false;
 			}
 		}
 	}
@@ -94,7 +102,7 @@ public class InjectionExtension implements BeforeEachCallback, AfterEachCallback
 	protected void setupRegistry(IInjectorProvider injectorProvider, ExtensionContext context) {
 		if (injectorProvider instanceof IRegistryConfigurator) {
 			IRegistryConfigurator registryConfigurator = (IRegistryConfigurator) injectorProvider;
-			context.getStore(Namespace.create(this)).getOrComputeIfAbsent(registryConfigurator, RegistryReset::new, RegistryReset.class);
+			context.getStore(Namespace.create(this)).getOrComputeIfAbsent(registryConfigurator, RegistryReset::new, RegistryReset.class).setup();
 		}
 	}
 

org.eclipse.xtext.testing/tests/org/eclipse/xtext/testing/tests/AbstractJUnitIntegrationTest.java

@@ -17,7 +17,8 @@ import org.junit.After;
 import org.junit.AfterClass;
 import org.junit.Before;
 import org.junit.jupiter.api.AfterAll;
-import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
 
 import com.google.inject.Binder;
 import com.google.inject.Guice;
@@ -59,13 +60,18 @@ public abstract class AbstractJUnitIntegrationTest {
 		@Override
 		public void setupRegistry() {
 			registrySaved = true;
-			assertFalse(injectorCreated);
+			if (!registryRestored) {
+				assertFalse(injectorCreated);
+			} else {
+				registryRestored = false;
+			}
 		}
 
 		@Override
 		public void restoreRegistry() {
 			assertTrue(registrySaved);
 			registryRestored = true;
+			registrySaved = false;
 		}
 	}
 	
@@ -78,19 +84,18 @@ public abstract class AbstractJUnitIntegrationTest {
 	}
 	
 	@Before
-	public void beforeShouldBeExecutedAfterTheRegistriesAreInitialized(){
+	@BeforeEach
+	public final void beforeShouldBeExecutedAfterTheRegistriesAreInitialized(){
 		assertTrue(registrySaved);
 		assertTrue(injectorCreated);
 		assertTrue(fieldsInjected);
 	}
 	
-	@Test
-	public void shouldSaveRegistriesBeforeCreatingAnInjector() {
-		// tests are performed in MyInjectorProvider
-	}
+	public abstract void shouldSaveRegistriesBeforeCreatingAnInjector();
 	
 	@After
-	public void afterShouldBeExecutedBeforeTheRegistriesAreRestored(){
+	@AfterEach
+	public final void afterShouldBeExecutedBeforeTheRegistriesAreRestored(){
 		assertFalse(registryRestored);
 	}
 }

org.eclipse.xtext.testing/tests/org/eclipse/xtext/testing/tests/XtextRunnerTest.java

@@ -9,12 +9,17 @@
 package org.eclipse.xtext.testing.tests;
 
 import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
 
 import org.eclipse.xtext.testing.InjectWith;
 import org.eclipse.xtext.testing.XtextRunner;
 import org.junit.Before;
+import org.junit.Rule;
 import org.junit.Test;
+import org.junit.rules.TestRule;
+import org.junit.runner.Description;
 import org.junit.runner.RunWith;
+import org.junit.runners.model.Statement;
 
 import com.google.inject.Inject;
 import com.google.inject.Injector;
@@ -28,13 +33,27 @@ public class XtextRunnerTest extends AbstractJUnitIntegrationTest {
 	@Inject
 	private Injector injector;
 	
-	/**
-	 * Need to override, otherwise no tests are found in Gradle build
-	 */
-	@Test
-	@Override
-	public void shouldSaveRegistriesBeforeCreatingAnInjector() {
-		super.shouldSaveRegistriesBeforeCreatingAnInjector();
+	@Inject
+	@Rule
+	public SomeRule someRule;
+	
+	static class SomeRule implements TestRule {
+		@Inject Injector injector;
+		boolean didApplyRule;
+
+		@Override
+		public Statement apply(Statement base, Description description) {
+			return new Statement() {
+				
+				@Override
+				public void evaluate() throws Throwable {
+					assertNotNull(injector);
+					didApplyRule = true;
+					base.evaluate();
+					didApplyRule = false;
+				}
+			};
+		}
 	}
 	
 	@Before
@@ -42,4 +61,18 @@ public class XtextRunnerTest extends AbstractJUnitIntegrationTest {
 		assertNotNull(injector);
 	}
 	
+	/**
+	 * Need to override to add proper {@code @Test}, otherwise no tests are found in Gradle build
+	 */
+	@Test
+	@Override
+	public void shouldSaveRegistriesBeforeCreatingAnInjector() {
+		// tests are performed in MyInjectorProvider
+	}
+
+	@Test
+	public void didUseTestRule() {
+		assertNotNull(someRule);
+		assertTrue(someRule.didApplyRule);
+	}
 }

org.eclipse.xtext.testing/tests/org/eclipse/xtext/testing/tests/junit5/InjectionExtensionTest.java

@@ -54,11 +54,19 @@ public class InjectionExtensionTest extends AbstractJUnitIntegrationTest {
 		Assertions.assertNotNull(injector);
 	}
 	
+	/**
+	 * Need to override to add proper {@code @Test}, otherwise no tests are found in Gradle build
+	 */
+	@Test
+	@Override
+	public void shouldSaveRegistriesBeforeCreatingAnInjector() {
+		// tests are performed in MyInjectorProvider
+	}
+	
 	@Test
 	public void didUseRegisteredExtension() {
 		Assertions.assertNotNull(registeredExtension);
 		Assertions.assertTrue(registeredExtension.didCallBeforeEach);
 	}
 	
-	
 }