From e2cc4fe2a436242ed332fbd5dfd1c47e75853a26 Mon Sep 17 00:00:00 2001
From: Oliver Drotbohm <odrotbohm@vmware.com>
Date: Fri, 3 Nov 2023 20:16:38 +0100
Subject: [PATCH] GH-345 - Properly handle manually declared entity scan and
 autoconfiguration packages.

If Spring Modulith packages were explicitly configured as autoconfiguration or entity scan packages, the test autoconfiguration would fail as it previously attempted to manipulate an immutable list. We now create a copy of that list to fix this.
---
 .../test/ModuleTestAutoConfiguration.java     |  6 +-
 ...TestAutoConfigurationIntegrationTests.java | 58 +++++++++++++++++++
 2 files changed, 62 insertions(+), 2 deletions(-)
 create mode 100644 spring-modulith-test/src/test/java/org/springframework/modulith/test/ModuleTestAutoConfigurationIntegrationTests.java

diff --git a/spring-modulith-test/src/main/java/org/springframework/modulith/test/ModuleTestAutoConfiguration.java b/spring-modulith-test/src/main/java/org/springframework/modulith/test/ModuleTestAutoConfiguration.java
index 38e991a8..237b4917 100644
--- a/spring-modulith-test/src/main/java/org/springframework/modulith/test/ModuleTestAutoConfiguration.java
+++ b/spring-modulith-test/src/main/java/org/springframework/modulith/test/ModuleTestAutoConfiguration.java
@@ -15,6 +15,7 @@
  */
 package org.springframework.modulith.test;
 
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 
@@ -72,14 +73,15 @@ class ModuleTestAutoConfiguration {
 				return;
 			}
 
+			var packagesToSet = new ArrayList<>(packages);
 			var definition = registry.getBeanDefinition(beanName);
 			var holder = definition.getConstructorArgumentValues().getArgumentValue(0, String[].class);
 
 			Arrays.stream((String[]) holder.getValue())
 					.filter(it -> it.startsWith("org.springframework.modulith"))
-					.forEach(packages::add);
+					.forEach(packagesToSet::add);
 
-			definition.getConstructorArgumentValues().addIndexedArgumentValue(0, packages.toArray(String[]::new));
+			definition.getConstructorArgumentValues().addIndexedArgumentValue(0, packagesToSet.toArray(String[]::new));
 		}
 	}
 }
diff --git a/spring-modulith-test/src/test/java/org/springframework/modulith/test/ModuleTestAutoConfigurationIntegrationTests.java b/spring-modulith-test/src/test/java/org/springframework/modulith/test/ModuleTestAutoConfigurationIntegrationTests.java
new file mode 100644
index 00000000..b3c9fbe2
--- /dev/null
+++ b/spring-modulith-test/src/test/java/org/springframework/modulith/test/ModuleTestAutoConfigurationIntegrationTests.java
@@ -0,0 +1,58 @@
+/*
+ * Copyright 2023 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.boot.autoconfigure.AutoConfigurations;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.boot.autoconfigure.domain.EntityScan;
+import org.springframework.boot.autoconfigure.domain.EntityScanPackages;
+import org.springframework.boot.test.context.runner.ApplicationContextRunner;
+
+/**
+ * Integration tests for {@link ModuleTestAutoConfiguration}.
+ *
+ * @author Oliver Drotbohm
+ */
+class ModuleTestAutoConfigurationIntegrationTests {
+
+	@Test // GH-345
+	void bootstrapsTestWithManualEntityScanOfModulithPackage() {
+
+		new ApplicationContextRunner()
+				.withBean(ModuleTestExecution.class, ModuleTestExecution.of(ModuleTest.class))
+				.withConfiguration(AutoConfigurations.of(ModuleTestAutoConfiguration.class))
+				.withUserConfiguration(ManualModulithEntityScan.class)
+				.run(ctx -> {
+
+					assertThat(ctx).hasNotFailed();
+					assertThat(ctx.getBean(EntityScanPackages.class).getPackageNames())
+							.containsExactlyInAnyOrder("org.springframework.modulith.test",
+									"org.springframework.modulith.events.jpa");
+				});
+	}
+
+	@SpringBootApplication
+	@ApplicationModuleTest
+	static class ModuleTest {}
+
+	@EnableAutoConfiguration
+	@EntityScan("org.springframework.modulith.events.jpa")
+	static class ManualModulithEntityScan {}
+}