GH-757 - Fix test context cache key contributions.

Both ModuleContextCustomizer and ModuleTypeExcludeFilter contribute to the calculation of the context configuration which the Spring Test Context Framework uses to decide whether it's necessary to create new ApplicationContext instances.

Both of them previously used a Supplier<ModuleTestExecution> to calculate equals(…) and hashCode() which -- by definition -- does not result in the same result even when created with identical input. We now rather use the source class instance eventually backing the ModuleTestExecution, as that is the internal cache key in turn.

spring-modulith-test/src/main/java/org/springframework/modulith/test/ModuleContextCustomizerFactory.java

@@ -62,9 +62,12 @@ static class ModuleContextCustomizer implements ContextCustomizer {
 		private static final Logger LOGGER = LoggerFactory.getLogger(ModuleContextCustomizer.class);
 
 		private final Supplier<ModuleTestExecution> execution;
+		private final Class<?> source;
+
+		ModuleContextCustomizer(Class<?> testClass) {
 
-		private ModuleContextCustomizer(Class<?> testClass) {
 			this.execution = ModuleTestExecution.of(testClass);
+			this.source = testClass;
 		}
 
 		/*
@@ -143,24 +146,12 @@ private static void logModules(ModuleTestExecution execution) {
 			LOGGER.info("");
 		}
 
-		private static void logHeadline(String headline) {
-			logHeadline(headline, () -> {});
-		}
-
-		private static void logHeadline(String headline, Runnable additional) {
-
-			LOGGER.info("");
-			LOGGER.info(headline);
-			additional.run();
-		}
-
 		/*
 		 * (non-Javadoc)
 		 * @see java.lang.Object#equals(java.lang.Object)
 		 */
 		@Override
 		public boolean equals(Object obj) {
-
 			if (this == obj) {
 				return true;
 			}
@@ -169,7 +160,7 @@ public boolean equals(Object obj) {
 				return false;
 			}
 
-			return Objects.equals(execution, that.execution);
+			return Objects.equals(this.source, that.source);
 		}
 
 		/*
@@ -178,7 +169,18 @@ public boolean equals(Object obj) {
 		 */
 		@Override
 		public int hashCode() {
-			return Objects.hash(execution);
+			return Objects.hashCode(source);
+		}
+
+		private static void logHeadline(String headline) {
+			logHeadline(headline, () -> {});
+		}
+
+		private static void logHeadline(String headline, Runnable additional) {
+
+			LOGGER.info("");
+			LOGGER.info(headline);
+			additional.run();
 		}
 	}
 

spring-modulith-test/src/main/java/org/springframework/modulith/test/ModuleTypeExcludeFilter.java

@@ -22,16 +22,22 @@
 import org.springframework.boot.context.TypeExcludeFilter;
 import org.springframework.core.type.classreading.MetadataReader;
 import org.springframework.core.type.classreading.MetadataReaderFactory;
+import org.springframework.util.Assert;
 
 /**
  * @author Oliver Drotbohm
  */
 class ModuleTypeExcludeFilter extends TypeExcludeFilter {
 
 	private final Supplier<ModuleTestExecution> execution;
+	private final Class<?> source;
 
 	public ModuleTypeExcludeFilter(Class<?> testClass) {
+
+		Assert.notNull(testClass, "Test class must not be null!");
+
 		this.execution = ModuleTestExecution.of(testClass);
+		this.source = testClass;
 	}
 
 	/*
@@ -58,7 +64,7 @@ public boolean equals(Object obj) {
 			return false;
 		}
 
-		return Objects.equals(execution, that.execution);
+		return Objects.equals(source, that.source);
 	}
 
 	/*
@@ -67,6 +73,6 @@ public boolean equals(Object obj) {
 	 */
 	@Override
 	public int hashCode() {
-		return Objects.hash(execution);
+		return Objects.hash(source);
 	}
 }

spring-modulith-test/src/test/java/org/springframework/modulith/test/ModuleContextCustomizerUnitTests.java

@@ -0,0 +1,40 @@
+/*
+ * Copyright 2024 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.modulith.test;
+
+import static org.assertj.core.api.Assertions.*;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.modulith.test.ModuleContextCustomizerFactory.ModuleContextCustomizer;
+
+/**
+ * Unit tests for {@link ModuleTypeExcludeFilter}.
+ *
+ * @author Oliver Drotbohm
+ */
+class ModuleContextCustomizerUnitTests {
+
+	@Test
+	void instancesForSameTargetTypeAreEqual() {
+
+		var left = new ModuleContextCustomizer(Object.class);
+		var right = new ModuleContextCustomizer(Object.class);
+
+		assertThat(left).isEqualTo(right);
+		assertThat(right).isEqualTo(left);
+		assertThat(left).hasSameHashCodeAs(right);
+	}
+}

spring-modulith-test/src/test/java/org/springframework/modulith/test/ModuleTypeExcludeFilterUnitTests.java

@@ -0,0 +1,39 @@
+/*
+ * Copyright 2024 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.modulith.test;
+
+import static org.assertj.core.api.Assertions.*;
+
+import org.junit.jupiter.api.Test;
+
+/**
+ * Unit tests for {@link ModuleTypeExcludeFilter}.
+ *
+ * @author Oliver Drotbohm
+ */
+class ModuleTypeExcludeFilterUnitTests {
+
+	@Test
+	void instancesForSameTargetTypeAreEqual() {
+
+		var left = new ModuleTypeExcludeFilter(Object.class);
+		var right = new ModuleTypeExcludeFilter(Object.class);
+
+		assertThat(left).isEqualTo(right);
+		assertThat(right).isEqualTo(left);
+		assertThat(left).hasSameHashCodeAs(right);
+	}
+}