Add SpringBootTest.useMainMethod support

Add a new `useMainMethod` attribute to `SpringBootTest` which can be
used to determine how the test should run. The three available options
are:

	- `ALWAYS`
	- `NEVER`
	- `WHEN_AVAILABLE`

The default is `WHEN_AVAILABLE` which will attempt to launch the test
using the `main` method if there is one.

The `SpringBootContextLoader` has been updated to use the new
`SpringApplicationHook` interface when the main method is being used.

Closes gh-22405

spring-boot-project/spring-boot-test/src/main/java/org/springframework/boot/test/context/SpringBootContextLoader.java

@@ -16,16 +16,23 @@
 
 package org.springframework.boot.test.context;
 
+import java.lang.reflect.Method;
+import java.time.Duration;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 
 import org.springframework.beans.BeanUtils;
 import org.springframework.boot.ApplicationContextFactory;
+import org.springframework.boot.ConfigurableBootstrapContext;
 import org.springframework.boot.SpringApplication;
+import org.springframework.boot.SpringApplication.AbandonedRunException;
+import org.springframework.boot.SpringApplicationHook;
+import org.springframework.boot.SpringApplicationRunListener;
+import org.springframework.boot.SpringBootConfiguration;
 import org.springframework.boot.WebApplicationType;
 import org.springframework.boot.context.event.ApplicationEnvironmentPreparedEvent;
-import org.springframework.boot.test.context.SpringBootTest.WebEnvironment;
+import org.springframework.boot.test.context.SpringBootTest.UseMainMethod;
 import org.springframework.boot.test.mock.web.SpringBootMockServletContext;
 import org.springframework.boot.test.util.TestPropertyValues;
 import org.springframework.boot.test.util.TestPropertyValues.Type;
@@ -54,7 +61,9 @@ import org.springframework.test.context.support.TestPropertySourceUtils;
 import org.springframework.test.context.web.WebMergedContextConfiguration;
 import org.springframework.util.Assert;
 import org.springframework.util.ObjectUtils;
+import org.springframework.util.ReflectionUtils;
 import org.springframework.util.StringUtils;
+import org.springframework.util.function.ThrowingSupplier;
 import org.springframework.web.context.ConfigurableWebApplicationContext;
 import org.springframework.web.context.support.GenericWebApplicationContext;
 
@@ -86,7 +95,47 @@ public class SpringBootContextLoader extends AbstractContextLoader {
 	@Override
 	public ApplicationContext loadContext(MergedContextConfiguration mergedConfig) throws Exception {
 		assertHasClassesOrLocations(mergedConfig);
+		SpringBootTestAnnotation annotation = SpringBootTestAnnotation.get(mergedConfig);
+		String[] args = annotation.getArgs();
+		UseMainMethod useMainMethod = annotation.getUseMainMethod();
+		ContextLoaderHook hook = new ContextLoaderHook(mergedConfig);
+		if (useMainMethod != UseMainMethod.NEVER) {
+			Method mainMethod = getMainMethod(mergedConfig, useMainMethod);
+			if (mainMethod != null) {
+				return hook.run(() -> ReflectionUtils.invokeMethod(mainMethod, null, new Object[] { args }));
+			}
+		}
 		SpringApplication application = getSpringApplication();
+		return hook.run(() -> application.run(args));
+	}
+
+	private void assertHasClassesOrLocations(MergedContextConfiguration mergedConfig) {
+		boolean hasClasses = !ObjectUtils.isEmpty(mergedConfig.getClasses());
+		boolean hasLocations = !ObjectUtils.isEmpty(mergedConfig.getLocations());
+		Assert.state(hasClasses || hasLocations,
+				() -> "No configuration classes or locations found in @SpringApplicationConfiguration. "
+						+ "For default configuration detection to work you need Spring 4.0.3 or better (found "
+						+ SpringVersion.getVersion() + ").");
+	}
+
+	private Method getMainMethod(MergedContextConfiguration mergedConfig, UseMainMethod useMainMethod) {
+		Class<?> springBootConfiguration = Arrays.stream(mergedConfig.getClasses())
+				.filter(this::isSpringBootConfiguration).findFirst().orElse(null);
+		Assert.state(springBootConfiguration != null || useMainMethod == UseMainMethod.WHEN_AVAILABLE,
+				"Cannot use main method as no @SpringBootConfiguration-annotated class is available");
+		Method mainMethod = (springBootConfiguration != null)
+				? ReflectionUtils.findMethod(springBootConfiguration, "main", String[].class) : null;
+		Assert.state(mainMethod != null || useMainMethod == UseMainMethod.WHEN_AVAILABLE,
+				() -> "Main method not found on '%s'".formatted(springBootConfiguration.getName()));
+		return mainMethod;
+	}
+
+	private boolean isSpringBootConfiguration(Class<?> candidate) {
+		return MergedAnnotations.from(candidate, SearchStrategy.TYPE_HIERARCHY)
+				.isPresent(SpringBootConfiguration.class);
+	}
+
+	private void configure(MergedContextConfiguration mergedConfig, SpringApplication application) {
 		application.setMainApplicationClass(mergedConfig.getTestClass());
 		application.addPrimarySources(Arrays.asList(mergedConfig.getClasses()));
 		application.getSources().addAll(Arrays.asList(mergedConfig.getLocations()));
@@ -103,7 +152,8 @@ public class SpringBootContextLoader extends AbstractContextLoader {
 		else {
 			application.setWebApplicationType(WebApplicationType.NONE);
 		}
-		application.setApplicationContextFactory((type) -> getApplicationContextFactory(mergedConfig, type));
+		application.setApplicationContextFactory(
+				(webApplicationType) -> getApplicationContextFactory(mergedConfig, webApplicationType));
 		application.setInitializers(initializers);
 		ConfigurableEnvironment environment = getEnvironment();
 		if (environment != null) {
@@ -113,30 +163,19 @@ public class SpringBootContextLoader extends AbstractContextLoader {
 		else {
 			application.addListeners(new PrepareEnvironmentListener(mergedConfig));
 		}
-		String[] args = SpringBootTestArgs.get(mergedConfig.getContextCustomizers());
-		return application.run(args);
-	}
-
-	private void assertHasClassesOrLocations(MergedContextConfiguration mergedConfig) {
-		boolean hasClasses = !ObjectUtils.isEmpty(mergedConfig.getClasses());
-		boolean hasLocations = !ObjectUtils.isEmpty(mergedConfig.getLocations());
-		Assert.state(hasClasses || hasLocations,
-				() -> "No configuration classes or locations found in @SpringApplicationConfiguration. "
-						+ "For default configuration detection to work you need Spring 4.0.3 or better (found "
-						+ SpringVersion.getVersion() + ").");
 	}
 
 	private ConfigurableApplicationContext getApplicationContextFactory(MergedContextConfiguration mergedConfig,
-			WebApplicationType type) {
-		if (type != WebApplicationType.NONE && !isEmbeddedWebEnvironment(mergedConfig)) {
-			if (type == WebApplicationType.REACTIVE) {
+			WebApplicationType webApplicationType) {
+		if (webApplicationType != WebApplicationType.NONE && !isEmbeddedWebEnvironment(mergedConfig)) {
+			if (webApplicationType == WebApplicationType.REACTIVE) {
 				return new GenericReactiveWebApplicationContext();
 			}
-			if (type == WebApplicationType.SERVLET) {
+			if (webApplicationType == WebApplicationType.SERVLET) {
 				return new GenericWebApplicationContext();
 			}
 		}
-		return ApplicationContextFactory.DEFAULT.create(type);
+		return ApplicationContextFactory.DEFAULT.create(webApplicationType);
 	}
 
 	private void prepareEnvironment(MergedContextConfiguration mergedConfig, SpringApplication application,
@@ -165,9 +204,10 @@ public class SpringBootContextLoader extends AbstractContextLoader {
 	}
 
 	/**
-	 * Builds new {@link org.springframework.boot.SpringApplication} instance. You can
-	 * override this method to add custom behavior
-	 * @return {@link org.springframework.boot.SpringApplication} instance
+	 * Builds new {@link org.springframework.boot.SpringApplication} instance. This method
+	 * is only called when a {@code main} method isn't being used to create the
+	 * {@link SpringApplication}.
+	 * @return a {@link SpringApplication} instance
 	 */
 	protected SpringApplication getSpringApplication() {
 		return new SpringApplication();
@@ -215,16 +255,14 @@ public class SpringBootContextLoader extends AbstractContextLoader {
 			initializers.add(BeanUtils.instantiateClass(initializerClass));
 		}
 		if (mergedConfig.getParent() != null) {
-			initializers
-					.add(new ParentContextApplicationContextInitializer(mergedConfig.getParentApplicationContext()));
+			ApplicationContext parentApplicationContext = mergedConfig.getParentApplicationContext();
+			initializers.add(new ParentContextApplicationContextInitializer(parentApplicationContext));
 		}
 		return initializers;
 	}
 
 	private boolean isEmbeddedWebEnvironment(MergedContextConfiguration mergedConfig) {
-		return MergedAnnotations.from(mergedConfig.getTestClass(), SearchStrategy.TYPE_HIERARCHY)
-				.get(SpringBootTest.class).getValue("webEnvironment", WebEnvironment.class).orElse(WebEnvironment.NONE)
-				.isEmbedded();
+		return SpringBootTestAnnotation.get(mergedConfig).getWebEnvironment().isEmbedded();
 	}
 
 	@Override
@@ -371,4 +409,45 @@ public class SpringBootContextLoader extends AbstractContextLoader {
 
 	}
 
+	/**
+	 * {@link SpringApplicationHook} used to capture the {@link ApplicationContext} and to
+	 * trigger early exit for the {@link Mode#AOT_PROCESSING} mode.
+	 */
+	private class ContextLoaderHook implements SpringApplicationHook {
+
+		private final MergedContextConfiguration mergedConfig;
+
+		ContextLoaderHook(MergedContextConfiguration mergedConfig) {
+			this.mergedConfig = mergedConfig;
+		}
+
+		@Override
+		public SpringApplicationRunListener getRunListener(SpringApplication application) {
+			return new SpringApplicationRunListener() {
+
+				@Override
+				public void starting(ConfigurableBootstrapContext bootstrapContext) {
+					SpringBootContextLoader.this.configure(ContextLoaderHook.this.mergedConfig, application);
+				}
+
+				@Override
+				public void ready(ConfigurableApplicationContext context, Duration timeTaken) {
+					throw new AbandonedRunException(context);
+				}
+
+			};
+		}
+
+		private <T> ApplicationContext run(ThrowingSupplier<T> action) {
+			try {
+				SpringApplication.withHook(this, action);
+				throw new IllegalStateException("ApplicationContext not loaded");
+			}
+			catch (AbandonedRunException ex) {
+				return ex.getApplicationContext();
+			}
+		}
+
+	}
+
 }

spring-boot-project/spring-boot-test/src/main/java/org/springframework/boot/test/context/SpringBootTest.java

@@ -125,6 +125,14 @@ public @interface SpringBootTest {
 	 */
 	WebEnvironment webEnvironment() default WebEnvironment.MOCK;
 
+	/**
+	 * The type of main method usage to employ when creating the {@link SpringApplication}
+	 * under test.
+	 * @return the type of main method usage
+	 * @since 3.0.0
+	 */
+	UseMainMethod useMainMethod() default UseMainMethod.WHEN_AVAILABLE;
+
 	/**
 	 * An enumeration web environment modes.
 	 */
@@ -175,4 +183,34 @@ public @interface SpringBootTest {
 
 	}
 
+	/**
+	 * Enumeration of how the main method of the
+	 * {@link SpringBootConfiguration @SpringBootConfiguration}-annotated class is used
+	 * when creating and running the {@link SpringApplication} under test.
+	 */
+	enum UseMainMethod {
+
+		/**
+		 * Always use the {@code main} method. A failure will occur if there is no
+		 * {@link SpringBootConfiguration @SpringBootConfiguration}-annotated class or
+		 * that class does not have a main method.
+		 */
+		ALWAYS,
+
+		/**
+		 * Never use the {@code main} method, creating a test-specific
+		 * {@link SpringApplication} instead.
+		 */
+		NEVER,
+
+		/**
+		 * Use the {@code main} method when it is available. If there is no
+		 * {@link SpringBootConfiguration @SpringBootConfiguration}-annotated class or
+		 * that class does not have a main method, a test-specific
+		 * {@link SpringApplication} will be used.
+		 */
+		WHEN_AVAILABLE;
+
+	}
+
 }

spring-boot-project/spring-boot-test/src/main/java/org/springframework/boot/test/context/SpringBootTestAnnotation.java

@@ -0,0 +1,115 @@
+/*
+ * Copyright 2012-2022 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.boot.test.context;
+
+import java.util.Arrays;
+import java.util.Objects;
+
+import org.springframework.boot.test.context.SpringBootTest.UseMainMethod;
+import org.springframework.boot.test.context.SpringBootTest.WebEnvironment;
+import org.springframework.context.ConfigurableApplicationContext;
+import org.springframework.test.context.ContextCustomizer;
+import org.springframework.test.context.MergedContextConfiguration;
+import org.springframework.test.context.TestContextAnnotationUtils;
+
+/**
+ * {@link ContextCustomizer} to track attributes of
+ * {@link SpringBootTest @SptringBootTest} that are taken into account when evaluating a
+ * {@link MergedContextConfiguration} to determine if a context can be shared between
+ * tests.
+ *
+ * @author Phillip Webb
+ * @author Madhura Bhave
+ * @author Andy Wilkinson
+ */
+class SpringBootTestAnnotation implements ContextCustomizer {
+
+	private static final String[] NO_ARGS = new String[0];
+
+	private static final SpringBootTestAnnotation DEFAULT = new SpringBootTestAnnotation((SpringBootTest) null);
+
+	private final String[] args;
+
+	private final WebEnvironment webEnvironment;
+
+	private final UseMainMethod useMainMethod;
+
+	SpringBootTestAnnotation(Class<?> testClass) {
+		this(TestContextAnnotationUtils.findMergedAnnotation(testClass, SpringBootTest.class));
+	}
+
+	private SpringBootTestAnnotation(SpringBootTest annotation) {
+		this.args = (annotation != null) ? annotation.args() : NO_ARGS;
+		this.webEnvironment = (annotation != null) ? annotation.webEnvironment() : WebEnvironment.NONE;
+		this.useMainMethod = (annotation != null) ? annotation.useMainMethod() : UseMainMethod.WHEN_AVAILABLE;
+	}
+
+	@Override
+	public void customizeContext(ConfigurableApplicationContext context, MergedContextConfiguration mergedConfig) {
+	}
+
+	@Override
+	public boolean equals(Object obj) {
+		if (this == obj) {
+			return true;
+		}
+		if (obj == null || getClass() != obj.getClass()) {
+			return false;
+		}
+		SpringBootTestAnnotation other = (SpringBootTestAnnotation) obj;
+		boolean result = Arrays.equals(this.args, other.args);
+		result = result && this.useMainMethod == other.useMainMethod;
+		result = result && this.webEnvironment == other.webEnvironment;
+		return result;
+	}
+
+	@Override
+	public int hashCode() {
+		final int prime = 31;
+		int result = 1;
+		result = prime * result + Arrays.hashCode(this.args);
+		result = prime * result + Objects.hash(this.useMainMethod, this.webEnvironment);
+		return result;
+	}
+
+	String[] getArgs() {
+		return this.args;
+	}
+
+	WebEnvironment getWebEnvironment() {
+		return this.webEnvironment;
+	}
+
+	UseMainMethod getUseMainMethod() {
+		return this.useMainMethod;
+	}
+
+	/**
+	 * Return the application arguments from the given {@link MergedContextConfiguration}.
+	 * @param mergedConfig the merged config to check
+	 * @return a {@link SpringBootTestAnnotation} instance
+	 */
+	static SpringBootTestAnnotation get(MergedContextConfiguration mergedConfig) {
+		for (ContextCustomizer customizer : mergedConfig.getContextCustomizers()) {
+			if (customizer instanceof SpringBootTestAnnotation annotation) {
+				return annotation;
+			}
+		}
+		return DEFAULT;
+	}
+
+}

spring-boot-project/spring-boot-test/src/main/java/org/springframework/boot/test/context/SpringBootTestArgs.java

@@ -1,79 +0,0 @@
-/*
- * Copyright 2012-2022 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.boot.test.context;
-
-import java.util.Arrays;
-import java.util.Set;
-
-import org.springframework.context.ConfigurableApplicationContext;
-import org.springframework.core.annotation.MergedAnnotations;
-import org.springframework.test.context.ContextCustomizer;
-import org.springframework.test.context.MergedContextConfiguration;
-
-/**
- * {@link ContextCustomizer} to track application arguments that are used in a
- * {@link SpringBootTest}. The application arguments are taken into account when
- * evaluating a {@link MergedContextConfiguration} to determine if a context can be shared
- * between tests.
- *
- * @author Madhura Bhave
- */
-class SpringBootTestArgs implements ContextCustomizer {
-
-	private static final String[] NO_ARGS = new String[0];
-
-	private final String[] args;
-
-	SpringBootTestArgs(Class<?> testClass) {
-		this.args = MergedAnnotations.from(testClass, MergedAnnotations.SearchStrategy.TYPE_HIERARCHY)
-				.get(SpringBootTest.class).getValue("args", String[].class).orElse(NO_ARGS);
-	}
-
-	@Override
-	public void customizeContext(ConfigurableApplicationContext context, MergedContextConfiguration mergedConfig) {
-	}
-
-	String[] getArgs() {
-		return this.args;
-	}
-
-	@Override
-	public boolean equals(Object obj) {
-		return (obj != null) && (getClass() == obj.getClass())
-				&& Arrays.equals(this.args, ((SpringBootTestArgs) obj).args);
-	}
-
-	@Override
-	public int hashCode() {
-		return Arrays.hashCode(this.args);
-	}
-
-	/**
-	 * Return the application arguments from the given customizers.
-	 * @param customizers the customizers to check
-	 * @return the application args or an empty array
-	 */
-	static String[] get(Set<ContextCustomizer> customizers) {
-		for (ContextCustomizer customizer : customizers) {
-			if (customizer instanceof SpringBootTestArgs testArgs) {
-				return testArgs.args;
-			}
-		}
-		return NO_ARGS;
-	}
-
-}

spring-boot-project/spring-boot-test/src/main/java/org/springframework/boot/test/context/SpringBootTestContextBootstrapper.java

@@ -362,8 +362,7 @@ public class SpringBootTestContextBootstrapper extends DefaultTestContextBootstr
 	protected final MergedContextConfiguration createModifiedConfig(MergedContextConfiguration mergedConfig,
 			Class<?>[] classes, String[] propertySourceProperties) {
 		Set<ContextCustomizer> contextCustomizers = new LinkedHashSet<>(mergedConfig.getContextCustomizers());
-		contextCustomizers.add(new SpringBootTestArgs(mergedConfig.getTestClass()));
-		contextCustomizers.add(new SpringBootTestWebEnvironment(mergedConfig.getTestClass()));
+		contextCustomizers.add(new SpringBootTestAnnotation(mergedConfig.getTestClass()));
 		return new MergedContextConfiguration(mergedConfig.getTestClass(), mergedConfig.getLocations(), classes,
 				mergedConfig.getContextInitializerClasses(), mergedConfig.getActiveProfiles(),
 				mergedConfig.getPropertySourceLocations(), propertySourceProperties, contextCustomizers,

spring-boot-project/spring-boot-test/src/main/java/org/springframework/boot/test/context/SpringBootTestWebEnvironment.java

@@ -1,58 +0,0 @@
-/*
- * Copyright 2012-2020 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.boot.test.context;
-
-import org.springframework.boot.test.context.SpringBootTest.WebEnvironment;
-import org.springframework.context.ConfigurableApplicationContext;
-import org.springframework.test.context.ContextCustomizer;
-import org.springframework.test.context.MergedContextConfiguration;
-import org.springframework.test.context.TestContextAnnotationUtils;
-
-/**
- * {@link ContextCustomizer} to track the web environment that is used in a
- * {@link SpringBootTest}. The web environment is taken into account when evaluating a
- * {@link MergedContextConfiguration} to determine if a context can be shared between
- * tests.
- *
- * @author Andy Wilkinson
- */
-class SpringBootTestWebEnvironment implements ContextCustomizer {
-
-	private final WebEnvironment webEnvironment;
-
-	SpringBootTestWebEnvironment(Class<?> testClass) {
-		SpringBootTest sprintBootTest = TestContextAnnotationUtils.findMergedAnnotation(testClass,
-				SpringBootTest.class);
-		this.webEnvironment = (sprintBootTest != null) ? sprintBootTest.webEnvironment() : null;
-	}
-
-	@Override
-	public void customizeContext(ConfigurableApplicationContext context, MergedContextConfiguration mergedConfig) {
-	}
-
-	@Override
-	public boolean equals(Object obj) {
-		return (obj != null) && (getClass() == obj.getClass())
-				&& this.webEnvironment == ((SpringBootTestWebEnvironment) obj).webEnvironment;
-	}
-
-	@Override
-	public int hashCode() {
-		return (this.webEnvironment != null) ? this.webEnvironment.hashCode() : 0;
-	}
-
-}

spring-boot-project/spring-boot-test/src/test/java/org/springframework/boot/test/context/SpringBootContextLoaderTests.java

@@ -23,6 +23,9 @@ import java.util.stream.Collectors;
 import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.Test;
 
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.SpringBootConfiguration;
+import org.springframework.boot.test.context.SpringBootTest.UseMainMethod;
 import org.springframework.boot.test.util.TestPropertyValues;
 import org.springframework.boot.web.reactive.context.GenericReactiveWebApplicationContext;
 import org.springframework.context.ApplicationContext;
@@ -40,6 +43,7 @@ import org.springframework.test.util.ReflectionTestUtils;
 import org.springframework.web.context.WebApplicationContext;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatIllegalStateException;
 
 /**
  * Tests for {@link SpringBootContextLoader}
@@ -114,8 +118,7 @@ class SpringBootContextLoaderTests {
 		assertThat(getActiveProfiles(ActiveProfileWithComma.class)).containsExactly("profile1,2");
 	}
 
-	@Test
-	// gh-28776
+	@Test // gh-28776
 	void testPropertyValuesShouldTakePrecedenceWhenInlinedPropertiesPresent() {
 		TestContext context = new ExposedTestContextManager(SimpleConfig.class).getExposedTestContext();
 		StandardEnvironment environment = (StandardEnvironment) context.getApplicationContext().getEnvironment();
@@ -162,6 +165,37 @@ class SpringBootContextLoaderTests {
 		assertThat(context.getApplicationContext()).isInstanceOf(GenericReactiveWebApplicationContext.class);
 	}
 
+	@Test
+	void whenUseMainMethodAlwaysAndMainMethodThrowsException() {
+		TestContext testContext = new ExposedTestContextManager(UseMainMethodAlwaysAndMainMethodThrowsException.class)
+				.getExposedTestContext();
+		assertThatIllegalStateException().isThrownBy(testContext::getApplicationContext).havingCause()
+				.withMessageContaining("ThrownFromMain");
+	}
+
+	@Test
+	void whenUseMainMethodWhenAvailableAndNoMainMethod() {
+		TestContext testContext = new ExposedTestContextManager(UseMainMethodWhenAvailableAndNoMainMethod.class)
+				.getExposedTestContext();
+		ApplicationContext applicationContext = testContext.getApplicationContext();
+		assertThat(applicationContext.getEnvironment().getActiveProfiles()).isEmpty();
+	}
+
+	@Test
+	void whenUseMainMethodWhenAvailableAndMainMethod() {
+		TestContext testContext = new ExposedTestContextManager(UseMainMethodWhenAvailableAndMainMethod.class)
+				.getExposedTestContext();
+		ApplicationContext applicationContext = testContext.getApplicationContext();
+		assertThat(applicationContext.getEnvironment().getActiveProfiles()).contains("frommain");
+	}
+
+	@Test
+	void whenUseMainMethodNever() {
+		TestContext testContext = new ExposedTestContextManager(UseMainMethodNever.class).getExposedTestContext();
+		ApplicationContext applicationContext = testContext.getApplicationContext();
+		assertThat(applicationContext.getEnvironment().getActiveProfiles()).isEmpty();
+	}
+
 	private String[] getActiveProfiles(Class<?> testClass) {
 		TestContext testContext = new ExposedTestContextManager(testClass).getExposedTestContext();
 		ApplicationContext applicationContext = testContext.getApplicationContext();
@@ -239,11 +273,6 @@ class SpringBootContextLoaderTests {
 
 	}
 
-	@Configuration(proxyBeanMethods = false)
-	static class Config {
-
-	}
-
 	@SpringBootTest(classes = Config.class, args = "--spring.main.web-application-type=none")
 	static class ChangingWebApplicationTypeToNone {
 
@@ -254,6 +283,57 @@ class SpringBootContextLoaderTests {
 
 	}
 
+	@SpringBootTest(classes = ConfigWithThrowingMain.class, useMainMethod = UseMainMethod.ALWAYS)
+	static class UseMainMethodAlwaysAndMainMethodThrowsException {
+
+	}
+
+	@SpringBootTest(classes = ConfigWithNoMain.class, useMainMethod = UseMainMethod.WHEN_AVAILABLE)
+	static class UseMainMethodWhenAvailableAndNoMainMethod {
+
+	}
+
+	@SpringBootTest(classes = ConfigWithMain.class, useMainMethod = UseMainMethod.WHEN_AVAILABLE)
+	static class UseMainMethodWhenAvailableAndMainMethod {
+
+	}
+
+	@SpringBootTest(classes = ConfigWithMain.class, useMainMethod = UseMainMethod.NEVER)
+	static class UseMainMethodNever {
+
+	}
+
+	@Configuration(proxyBeanMethods = false)
+	static class Config {
+
+	}
+
+	@Configuration(proxyBeanMethods = false)
+	@SpringBootConfiguration
+	public static class ConfigWithMain {
+
+		public static void main(String[] args) {
+			new SpringApplication(ConfigWithMain.class).run("--spring.profiles.active=frommain");
+		}
+
+	}
+
+	@Configuration(proxyBeanMethods = false)
+	@SpringBootConfiguration
+	static class ConfigWithNoMain {
+
+	}
+
+	@Configuration(proxyBeanMethods = false)
+	@SpringBootConfiguration
+	public static class ConfigWithThrowingMain {
+
+		public static void main(String[] args) {
+			throw new RuntimeException("ThrownFromMain");
+		}
+
+	}
+
 	/**
 	 * {@link TestContextManager} which exposes the {@link TestContext}.
 	 */