Unit test for no resources in the target folder

org.eclipse.m2e.core.tests/resources/projects/demo/pom.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<parent>
+		<groupId>org.springframework.boot</groupId>
+		<artifactId>spring-boot-starter-parent</artifactId>
+		<version>3.0.8</version>
+		<relativePath/> <!-- lookup parent from repository -->
+	</parent>
+	<groupId>com.example</groupId>
+	<artifactId>demo</artifactId>
+	<version>0.0.1-SNAPSHOT</version>
+	<name>demo</name>
+	<description>Demo project for Spring Boot</description>
+	<properties>
+		<java.version>17</java.version>
+	</properties>
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter</artifactId>
+		</dependency>
+
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-test</artifactId>
+			<scope>test</scope>
+		</dependency>
+	</dependencies>
+
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.springframework.boot</groupId>
+				<artifactId>spring-boot-maven-plugin</artifactId>
+			</plugin>
+		</plugins>
+	</build>
+
+</project>

org.eclipse.m2e.core.tests/resources/projects/demo/src/main/java/com/example/demo/DemoApplication.java

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+package com.example.demo;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class DemoApplication {
+
+	public static void main(String[] args) {
+		SpringApplication.run(DemoApplication.class, args);
+	}
+
+}

org.eclipse.m2e.core.tests/resources/projects/demo/src/main/resources/application.properties

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+

org.eclipse.m2e.core.tests/resources/projects/demo/src/test/java/com/example/demo/DemoApplicationTests.java

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+package com.example.demo;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.boot.test.context.SpringBootTest;
+
+@SpringBootTest
+class DemoApplicationTests {
+
+	@Test
+	void contextLoads() {
+	}
+
+}

org.eclipse.m2e.core.tests/src/org/eclipse/m2e/core/AppPropsNotCopiedIntoTargetTest.java

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+/*******************************************************************************
+ * Copyright (c) 2023 Alex Boyko and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License 2.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *******************************************************************************/
+package org.eclipse.m2e.core;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import java.io.ByteArrayInputStream;
+import java.io.File;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+import org.apache.commons.io.FileUtils;
+import org.eclipse.core.resources.IFile;
+import org.eclipse.core.resources.IProject;
+import org.eclipse.core.runtime.IPath;
+import org.eclipse.jdt.core.IJavaProject;
+import org.eclipse.jdt.core.JavaCore;
+import org.eclipse.m2e.tests.common.AbstractMavenProjectTestCase;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+public class AppPropsNotCopiedIntoTargetTest extends AbstractMavenProjectTestCase {
+
+	private File projectDirectory;
+
+	@Override
+	@Before
+	public void setUp() throws Exception {
+		super.setUp();
+	    setAutoBuilding(true);
+		projectDirectory = new File(Files.createTempDirectory("m2e-tests").toFile(), "demo");
+		projectDirectory.mkdirs();
+		copyDir(new File("resources/projects/demo"), projectDirectory);
+	}
+
+	@Override
+	@After
+	public void tearDown() throws Exception {
+		FileUtils.deleteDirectory(this.projectDirectory.getParentFile());
+		super.tearDown();
+	}
+
+	@Test
+	public void test() throws Exception {
+		IProject project = importProject(new File(projectDirectory, "pom.xml").toString());
+		waitForJobsToComplete(monitor);
+
+		IJavaProject jp = JavaCore.create(project);
+
+		assertTrue("Build Automatically is NOT on!", isAutoBuilding());
+
+		IPath rootPath = project.getWorkspace().getRoot().getLocation();
+
+		// Project imported for the first time and built - everything is properly in the target folder
+		assertTrue("'application.properties' is NOT in the output folder", rootPath.append(jp.getOutputLocation()).append("/application.properties").toFile()
+				.exists());
+		assertTrue("'DemoApplication.class' is NOT in the output folder", rootPath.append(jp.getOutputLocation())
+				.append("/com/example/demo/DemoApplication.class").makeAbsolute().toFile().exists());
+
+		IFile pomXml = project.getFile("pom.xml");
+		String content = Files.readString(Path.of(pomXml.getLocationURI()));
+		pomXml.setContents(new ByteArrayInputStream("Nothing".getBytes()), true, false, null);
+
+		waitForJobsToComplete(monitor);
+		Thread.sleep(5000);
+		// Invalid pom file. JavaBuilder built java sources but MavenBuilder wqs unable to do anything hence no resources in the target folder except for compiled classes
+		assertFalse("'application.properties' hasn't been removed from the output folder", rootPath.append(jp.getOutputLocation()).append("/application.properties").toFile()
+				.exists());
+		assertTrue("'DemoApplication.class' should be created in the output folder by JavaBuilder", rootPath.append(jp.getOutputLocation())
+				.append("/com/example/demo/DemoApplication.class").toFile().exists());
+
+		pomXml.setContents(new ByteArrayInputStream(content.getBytes()), true, false, null);
+		waitForJobsToComplete(monitor);
+		Thread.sleep(5000);
+		// Valid pom file. Compiled classes and resources should reappear in the target folder. However, resources are missing which makes the test fail
+		assertTrue("'DemoApplication.class' hasn't been created in the output folder", rootPath.append(jp.getOutputLocation())
+				.append("/com/example/demo/DemoApplication.class").toFile().exists());
+		assertTrue("'application.properties' hasn't been copied in the output folder", rootPath.append(jp.getOutputLocation()).append("/application.properties").toFile()
+				.exists());		
+	}
+
+}