Add testClasspath option to run and start goals

Deprecate the `useTestClasspath` flag in favor of a `testClasspath`
parameter on the `run` and `start` goals. It accepts `off`,
`dependencies`, or `all`, with `all` also adding the project's test
classes directory to the classpath so that a main class located in
`src/test/java` can be found and run, matching the `test-run` goal's
existing behaviour.

Closes gh-36115

build-plugin/spring-boot-maven-plugin/src/intTest/java/org/springframework/boot/maven/RunIntegrationTests.java

@@ -95,8 +95,31 @@ class RunIntegrationTests {
 	}
 
 	@TestTemplate
+	@Deprecated(since = "4.2.0", forRemoval = true)
 	void whenUseTestClasspathIsEnabledTheApplicationHasTestDependenciesOnItsClasspath(MavenBuild mavenBuild) {
 		mavenBuild.project("run-use-test-classpath")
+			.goals("spring-boot:run")
+			.execute((project) -> assertThat(buildLog(project)).contains("I haz been run")
+				.contains("useTestClasspath is deprecated, use testClasspath instead."));
+	}
+
+	@TestTemplate
+	void whenTestClasspathIsDependenciesTheApplicationHasTestDependenciesOnItsClasspath(MavenBuild mavenBuild) {
+		mavenBuild.project("run-test-classpath-dependencies")
+			.goals("spring-boot:run")
+			.execute((project) -> assertThat(buildLog(project)).contains("I haz been run"));
+	}
+
+	@TestTemplate
+	void whenTestClasspathIsAllTheApplicationHasTestAndClassesDependenciesOnItsClasspath(MavenBuild mavenBuild) {
+		mavenBuild.project("run-test-classpath-all")
+			.goals("spring-boot:run")
+			.execute((project) -> assertThat(buildLog(project)).contains("I haz been run"));
+	}
+
+	@TestTemplate
+	void whenTestClasspathIsOffTheApplicationHasNeitherTestNorClassesDependenciesOnItsClasspath(MavenBuild mavenBuild) {
+		mavenBuild.project("run-test-classpath-off")
 			.goals("spring-boot:run")
 			.execute((project) -> assertThat(buildLog(project)).contains("I haz been run"));
 	}

build-plugin/spring-boot-maven-plugin/src/intTest/java/org/springframework/boot/maven/StartStopIntegrationTests.java

@@ -34,7 +34,17 @@ class StartStopIntegrationTests {
 
 	@TestTemplate
 	void startStopWaitsForApplicationToBeReadyAndThenRequestsShutdown(MavenBuild mavenBuild) {
-		mavenBuild.project("start-stop")
+		testStartStop(mavenBuild, "start-stop");
+
+	}
+
+	@TestTemplate
+	void startStopWithTestClasspathWaitsForApplicationToBeReadyAndThenRequestsShutdown(MavenBuild mavenBuild) {
+		testStartStop(mavenBuild, "start-stop-test");
+	}
+
+	private void testStartStop(MavenBuild mavenBuild, String projectId) {
+		mavenBuild.project(projectId)
 			.goals("verify")
 			.execute((project) -> assertThat(buildLog(project)).contains("isReady: true")
 				.contains("Shutdown requested"));

build-plugin/spring-boot-maven-plugin/src/intTest/projects/run-test-classpath-all/pom.xml

@@ -0,0 +1,33 @@
+<?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>
+	<groupId>org.springframework.boot.maven.it</groupId>
+	<artifactId>run-test-classpath-all</artifactId>
+	<version>0.0.1.BUILD-SNAPSHOT</version>
+	<properties>
+		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+		<maven.compiler.source>@java.version@</maven.compiler.source>
+		<maven.compiler.target>@java.version@</maven.compiler.target>
+	</properties>
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>@project.groupId@</groupId>
+				<artifactId>@project.artifactId@</artifactId>
+				<version>@project.version@</version>
+				<configuration>
+					<testClasspath>all</testClasspath>
+				</configuration>
+			</plugin>
+		</plugins>
+	</build>
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework</groupId>
+			<artifactId>spring-context</artifactId>
+			<version>@spring-framework.version@</version>
+			<scope>test</scope>
+		</dependency>
+	</dependencies>
+</project>

build-plugin/spring-boot-maven-plugin/src/intTest/projects/run-test-classpath-all/src/test/java/org/test/SampleApplication.java

@@ -0,0 +1,33 @@
+/*
+ * Copyright 2012-present 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.test;
+
+public class SampleApplication {
+
+	public static void main(String[] args) {
+
+		Class<?> appContext = null;
+		try {
+			appContext = Class.forName("org.springframework.context.ApplicationContext");
+		}
+		catch (ClassNotFoundException e) {
+			throw new IllegalStateException("Test dependencies not added to classpath", e);
+		}
+		System.out.println("I haz been run");
+	}
+
+}

build-plugin/spring-boot-maven-plugin/src/intTest/projects/run-test-classpath-dependencies/pom.xml

@@ -0,0 +1,33 @@
+<?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>
+	<groupId>org.springframework.boot.maven.it</groupId>
+	<artifactId>run-test-classpath-dependencies</artifactId>
+	<version>0.0.1.BUILD-SNAPSHOT</version>
+	<properties>
+		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+		<maven.compiler.source>@java.version@</maven.compiler.source>
+		<maven.compiler.target>@java.version@</maven.compiler.target>
+	</properties>
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>@project.groupId@</groupId>
+				<artifactId>@project.artifactId@</artifactId>
+				<version>@project.version@</version>
+				<configuration>
+					<testClasspath>dependencies</testClasspath>
+				</configuration>
+			</plugin>
+		</plugins>
+	</build>
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework</groupId>
+			<artifactId>spring-context</artifactId>
+			<version>@spring-framework.version@</version>
+			<scope>test</scope>
+		</dependency>
+	</dependencies>
+</project>

build-plugin/spring-boot-maven-plugin/src/intTest/projects/run-test-classpath-dependencies/src/main/java/org/test/SampleApplication.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright 2012-present 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.test;
+
+public class SampleApplication {
+
+	public static void main(String[] args) {
+		try {
+			Class.forName("org.springframework.context.ApplicationContext");
+		}
+		catch (ClassNotFoundException e) {
+			throw new IllegalStateException("Test dependencies not added to classpath", e);
+		}
+		try {
+			Class.forName("org.test.SampleTest");
+			throw new IllegalStateException("Test classes should not have been added to classpath");
+		}
+		catch (ClassNotFoundException e) {
+			// OK
+		}
+		System.out.println("I haz been run");
+	}
+
+}

build-plugin/spring-boot-maven-plugin/src/intTest/projects/run-test-classpath-dependencies/src/test/java/org/test/SampleTest.java

@@ -0,0 +1,21 @@
+/*
+ * Copyright 2012-present 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.test;
+
+public class SampleTest {
+
+}

build-plugin/spring-boot-maven-plugin/src/intTest/projects/run-test-classpath-off/pom.xml

@@ -0,0 +1,33 @@
+<?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>
+	<groupId>org.springframework.boot.maven.it</groupId>
+	<artifactId>run-test-classpath-off</artifactId>
+	<version>0.0.1.BUILD-SNAPSHOT</version>
+	<properties>
+		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+		<maven.compiler.source>@java.version@</maven.compiler.source>
+		<maven.compiler.target>@java.version@</maven.compiler.target>
+	</properties>
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>@project.groupId@</groupId>
+				<artifactId>@project.artifactId@</artifactId>
+				<version>@project.version@</version>
+				<configuration>
+					<testClasspath>off</testClasspath>
+				</configuration>
+			</plugin>
+		</plugins>
+	</build>
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework</groupId>
+			<artifactId>spring-context</artifactId>
+			<version>@spring-framework.version@</version>
+			<scope>test</scope>
+		</dependency>
+	</dependencies>
+</project>

build-plugin/spring-boot-maven-plugin/src/intTest/projects/run-test-classpath-off/src/main/java/org/test/SampleApplication.java

@@ -0,0 +1,39 @@
+/*
+ * Copyright 2012-present 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.test;
+
+public class SampleApplication {
+
+	public static void main(String[] args) {
+		try {
+			Class.forName("org.springframework.context.ApplicationContext");
+			throw new IllegalStateException("Test dependencies should not have been added to classpath");
+		}
+		catch (ClassNotFoundException e) {
+			// OK
+		}
+		try {
+			Class.forName("org.test.SampleTest");
+			throw new IllegalStateException("Test classes should not have been added to classpath");
+		}
+		catch (ClassNotFoundException e) {
+			// OK
+		}
+		System.out.println("I haz been run");
+	}
+
+}

build-plugin/spring-boot-maven-plugin/src/intTest/projects/run-test-classpath-off/src/test/java/org/test/SampleTest.java

@@ -0,0 +1,21 @@
+/*
+ * Copyright 2012-present 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.test;
+
+public class SampleTest {
+
+}

build-plugin/spring-boot-maven-plugin/src/intTest/projects/start-stop-test/pom.xml

@@ -0,0 +1,59 @@
+<?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>
+	<groupId>org.springframework.boot.maven.it</groupId>
+	<artifactId>start-stop-test</artifactId>
+	<version>0.0.1.BUILD-SNAPSHOT</version>
+	<properties>
+		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+		<maven.compiler.source>@java.version@</maven.compiler.source>
+		<maven.compiler.target>@java.version@</maven.compiler.target>
+	</properties>
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.codehaus.mojo</groupId>
+				<artifactId>build-helper-maven-plugin</artifactId>
+				<version>@build-helper-maven-plugin.version@</version>
+				<executions>
+					<execution>
+						<id>reserve-jmx-port</id>
+						<goals>
+							<goal>reserve-network-port</goal>
+						</goals>
+						<phase>process-resources</phase>
+						<configuration>
+							<portNames>
+								<portName>jmx.port</portName>
+							</portNames>
+						</configuration>
+					</execution>
+				</executions>
+			</plugin>
+			<plugin>
+				<groupId>@project.groupId@</groupId>
+				<artifactId>@project.artifactId@</artifactId>
+				<version>@project.version@</version>
+				<executions>
+					<execution>
+						<id>pre-integration-test</id>
+						<goals>
+							<goal>start</goal>
+						</goals>
+					</execution>
+					<execution>
+						<id>post-integration-test</id>
+						<goals>
+							<goal>stop</goal>
+						</goals>
+					</execution>
+				</executions>
+				<configuration>
+					<jmxPort>${jmx.port}</jmxPort>
+					<testClasspath>all</testClasspath>
+				</configuration>
+			</plugin>
+		</plugins>
+	</build>
+</project>

build-plugin/spring-boot-maven-plugin/src/intTest/projects/start-stop-test/src/main/java/org/test/SpringApplicationAdmin.java

@@ -0,0 +1,37 @@
+/*
+ * Copyright 2012-present 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.test;
+
+final class SpringApplicationAdmin implements SpringApplicationAdminMXBean {
+
+	boolean ready;
+
+	boolean shutdownInvoked;
+
+	@Override
+	public boolean isReady() {
+		System.out.println("isReady: " + this.ready);
+		return this.ready;
+	}
+
+	@Override
+	public void shutdown() {
+		this.shutdownInvoked = true;
+		System.out.println("Shutdown requested");
+	}
+
+}

build-plugin/spring-boot-maven-plugin/src/intTest/projects/start-stop-test/src/main/java/org/test/SpringApplicationAdminMXBean.java

@@ -0,0 +1,25 @@
+/*
+ * Copyright 2012-present 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.test;
+
+public interface SpringApplicationAdminMXBean {
+
+	boolean isReady();
+
+	void shutdown();
+
+}

build-plugin/spring-boot-maven-plugin/src/intTest/projects/start-stop-test/src/test/java/org/test/SampleApplication.java

@@ -0,0 +1,54 @@
+/*
+ * Copyright 2012-present 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.test;
+
+import java.lang.management.ManagementFactory;
+
+import javax.management.MBeanServer;
+import javax.management.ObjectName;
+
+/**
+ * This sample app simulates the JMX Mbean that is exposed by the Spring Boot application.
+ */
+public class SampleApplication {
+
+	private static final Object lock = new Object();
+
+	public static void main(String[] args) throws Exception {
+		MBeanServer mbs = ManagementFactory.getPlatformMBeanServer();
+		ObjectName name = new ObjectName(
+				"org.springframework.boot:type=Admin,name=SpringApplication");
+		SpringApplicationAdmin mbean = new SpringApplicationAdmin();
+		mbs.registerMBean(mbean, name);
+
+		// Flag the app as ready
+		mbean.ready = true;
+
+		int waitAttempts = 0;
+		while (!mbean.shutdownInvoked) {
+			if (waitAttempts > 30) {
+				throw new IllegalStateException(
+						"Shutdown should have been invoked by now");
+			}
+			synchronized (lock) {
+				lock.wait(250);
+			}
+			waitAttempts++;
+		}
+	}
+
+}

build-plugin/spring-boot-maven-plugin/src/main/java/org/springframework/boot/maven/AbstractRunMojo.java

@@ -205,6 +205,16 @@ public abstract class AbstractRunMojo extends AbstractDependencyFilterMojo {
 	@SuppressWarnings("NullAway.Init")
 	private File classesDirectory;
 
+	/**
+	 * Directory containing the test classes and resource files that can be included when
+	 * running the application.
+	 *
+	 * @since 4.2.0
+	 */
+	@Parameter(defaultValue = "${project.build.testOutputDirectory}", required = true)
+	@SuppressWarnings("NullAway.Init")
+	private File testClassesDirectory;
+
 	/**
 	 * Skip the execution.
 	 *
@@ -241,10 +251,19 @@ public abstract class AbstractRunMojo extends AbstractDependencyFilterMojo {
 	 * @since 3.1.0
 	 */
 	protected List<File> getClassesDirectories() {
-		return List.of(this.classesDirectory);
+		List<File> classesDirectories = new ArrayList<>();
+		if (testClasspath() == TestClasspath.ALL) {
+			classesDirectories.add(this.testClassesDirectory);
+		}
+		classesDirectories.add(this.classesDirectory);
+		return Collections.unmodifiableList(classesDirectories);
 	}
 
-	protected abstract boolean isUseTestClasspath();
+	/**
+	 * Return the {@link TestClasspath} strategy to use.
+	 * @return the test classpath strategy
+	 */
+	protected abstract TestClasspath testClasspath();
 
 	private void run(String startClassName) throws MojoExecutionException, MojoFailureException {
 		List<String> args = new ArrayList<>();
@@ -416,7 +435,9 @@ public abstract class AbstractRunMojo extends AbstractDependencyFilterMojo {
 	}
 
 	private void addDependencies(List<URL> urls) throws MalformedURLException, MojoExecutionException {
-		Set<Artifact> artifacts = (isUseTestClasspath()) ? filterDependencies(this.project.getArtifacts())
+		TestClasspath testClasspath = testClasspath();
+		Set<Artifact> artifacts = ((testClasspath == TestClasspath.ALL || testClasspath == TestClasspath.DEPENDENCIES))
+				? filterDependencies(this.project.getArtifacts())
 				: filterDependencies(this.project.getArtifacts(), new ExcludeTestScopeArtifactFilter());
 		for (Artifact artifact : artifacts) {
 			if (artifact.getFile() != null) {
@@ -432,4 +453,27 @@ public abstract class AbstractRunMojo extends AbstractDependencyFilterMojo {
 		}
 	}
 
+	/**
+	 * Strategies to handle the test classpath when running an application.
+	 */
+	protected enum TestClasspath {
+
+		/**
+		 * Do not include the test classpath at all.
+		 */
+		OFF,
+
+		/**
+		 * Include only dependencies with test scope.
+		 */
+		DEPENDENCIES,
+
+		/**
+		 * Include the full test classpath (test classes and dependencies with test
+		 * scope).
+		 */
+		ALL
+
+	}
+
 }

build-plugin/spring-boot-maven-plugin/src/main/java/org/springframework/boot/maven/RunMojo.java

@@ -18,6 +18,7 @@ package org.springframework.boot.maven;
 
 import java.io.File;
 import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 
 import javax.inject.Inject;
@@ -30,6 +31,7 @@ import org.apache.maven.plugins.annotations.Mojo;
 import org.apache.maven.plugins.annotations.Parameter;
 import org.apache.maven.plugins.annotations.ResolutionScope;
 import org.apache.maven.toolchain.ToolchainManager;
+import org.jspecify.annotations.Nullable;
 
 import org.springframework.boot.loader.tools.RunProcess;
 
@@ -57,9 +59,24 @@ public class RunMojo extends AbstractRunMojo {
 	/**
 	 * Flag to include the test classpath when running.
 	 * @since 1.3.0
+	 * @deprecated since 4.2.0 for removal in 4.4.0 in favor of {@code testClasspath}
 	 */
-	@Parameter(property = "spring-boot.run.useTestClasspath", defaultValue = "false")
-	private boolean useTestClasspath;
+	@Parameter(property = "spring-boot.run.useTestClasspath")
+	@Deprecated(since = "4.2.0", forRemoval = true)
+	private @Nullable Boolean useTestClasspath;
+
+	/**
+	 * Strategy to determine how the test classpath should be included when running the
+	 * application. Available values are {@code off} to not include the test classpath at
+	 * all, {@code dependencies} to include only dependencies with test scope, and
+	 * {@code all} to include the full test classpath (test classes and dependencies with
+	 * test scope).
+	 * @since 4.2.0
+	 */
+	@Parameter(property = "spring-boot.run.testClasspath", defaultValue = "off")
+	private String testClasspath = "off";
+
+	private @Nullable TestClasspath resolvedTestClasspath;
 
 	@Inject
 	public RunMojo(ToolchainManager toolchainManager) {
@@ -85,8 +102,17 @@ public class RunMojo extends AbstractRunMojo {
 	}
 
 	@Override
-	protected boolean isUseTestClasspath() {
-		return this.useTestClasspath;
+	protected TestClasspath testClasspath() {
+		if (this.resolvedTestClasspath == null) {
+			if (this.useTestClasspath != null) {
+				getLog().warn("useTestClasspath is deprecated, use testClasspath instead.");
+				this.resolvedTestClasspath = (this.useTestClasspath) ? TestClasspath.DEPENDENCIES : TestClasspath.OFF;
+			}
+			else {
+				this.resolvedTestClasspath = TestClasspath.valueOf(this.testClasspath.toUpperCase(Locale.ROOT));
+			}
+		}
+		return this.resolvedTestClasspath;
 	}
 
 	private static final class RunProcessKiller implements Runnable {

build-plugin/spring-boot-maven-plugin/src/main/java/org/springframework/boot/maven/StartMojo.java

@@ -21,6 +21,7 @@ import java.io.IOException;
 import java.net.ConnectException;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 import java.util.concurrent.Callable;
 
@@ -91,9 +92,24 @@ public class StartMojo extends AbstractRunMojo {
 
 	/**
 	 * Flag to include the test classpath when running.
+	 * @deprecated since 4.2.0 for removal in 4.4.0 in favor of {@code testClasspath}
 	 */
-	@Parameter(property = "spring-boot.run.useTestClasspath", defaultValue = "false")
-	private boolean useTestClasspath;
+	@Parameter(property = "spring-boot.run.useTestClasspath")
+	@Deprecated(since = "4.2.0", forRemoval = true)
+	private @Nullable Boolean useTestClasspath;
+
+	/**
+	 * Strategy to determine how the test classpath should be included when running the
+	 * application. Available values are {@code off} to not include the test classpath at
+	 * all, {@code dependencies} to include only dependencies with test scope, and
+	 * {@code all} to include the full test classpath (test classes and dependencies with
+	 * test scope).
+	 * @since 4.2.0
+	 */
+	@Parameter(property = "spring-boot.run.testClasspath", defaultValue = "off")
+	private String testClasspath = "off";
+
+	private @Nullable TestClasspath resolvedTestClasspath;
 
 	@Inject
 	public StartMojo(ToolchainManager toolchainManager) {
@@ -205,8 +221,17 @@ public class StartMojo extends AbstractRunMojo {
 	}
 
 	@Override
-	protected boolean isUseTestClasspath() {
-		return this.useTestClasspath;
+	protected TestClasspath testClasspath() {
+		if (this.resolvedTestClasspath == null) {
+			if (this.useTestClasspath != null) {
+				getLog().warn("useTestClasspath is deprecated, use testClasspath instead.");
+				this.resolvedTestClasspath = (this.useTestClasspath) ? TestClasspath.DEPENDENCIES : TestClasspath.OFF;
+			}
+			else {
+				this.resolvedTestClasspath = TestClasspath.valueOf(this.testClasspath.toUpperCase(Locale.ROOT));
+			}
+		}
+		return this.resolvedTestClasspath;
 	}
 
 	private class CreateJmxConnector implements Callable<@Nullable JMXConnector> {

build-plugin/spring-boot-maven-plugin/src/main/java/org/springframework/boot/maven/TestRunMojo.java

@@ -17,7 +17,6 @@
 package org.springframework.boot.maven;
 
 import java.io.File;
-import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 
@@ -57,29 +56,14 @@ public class TestRunMojo extends AbstractRunMojo {
 	@Parameter(property = "spring-boot.test-run.optimizedLaunch", defaultValue = "true")
 	private boolean optimizedLaunch;
 
-	/**
-	 * Directory containing the test classes and resource files that should be used to run
-	 * the application.
-	 */
-	@Parameter(defaultValue = "${project.build.testOutputDirectory}", required = true)
-	@SuppressWarnings("NullAway.Init")
-	private File testClassesDirectory;
-
 	@Inject
 	public TestRunMojo(ToolchainManager toolchainManager) {
 		super(toolchainManager);
 	}
 
 	@Override
-	protected List<File> getClassesDirectories() {
-		ArrayList<File> classesDirectories = new ArrayList<>(super.getClassesDirectories());
-		classesDirectories.add(0, this.testClassesDirectory);
-		return classesDirectories;
-	}
-
-	@Override
-	protected boolean isUseTestClasspath() {
-		return true;
+	protected TestClasspath testClasspath() {
+		return TestClasspath.ALL;
 	}
 
 	@Override