Ensure that parameter resolution in SpringExtension is thread-safe

Prior to this commit, parallel execution of @BeforeEach and @AfterEach
methods that accepted @Autowired arguments would fail intermittently
due to a race condition in the internal implementation of the JDK's
java.lang.reflect.Executable.getParameters() method.

This commit addresses this issue by creating instances of
SynthesizingMethodParameter via
SynthesizingMethodParameter.forExecutable(Executable, int) instead of
SynthesizingMethodParameter.forParameter(Parameter), since the latter
looks up the parameter index by iterating over the array returned by
Executable.getParameters() (which is not thread-safe).

Issue: SPR-17533

spring-test/src/main/java/org/springframework/test/context/junit/jupiter/ParameterAutowireUtils.java

@@ -118,7 +118,8 @@ abstract class ParameterAutowireUtils {
 		Autowired autowired = AnnotatedElementUtils.findMergedAnnotation(annotatedParameter, Autowired.class);
 		boolean required = (autowired == null || autowired.required());
 
-		MethodParameter methodParameter = SynthesizingMethodParameter.forParameter(parameter);
+		MethodParameter methodParameter = SynthesizingMethodParameter.forExecutable(
+				parameter.getDeclaringExecutable(), parameterIndex);
 		DependencyDescriptor descriptor = new DependencyDescriptor(methodParameter, required);
 		descriptor.setContainingClass(containingClass);
 		return applicationContext.getAutowireCapableBeanFactory().resolveDependency(descriptor, null);

spring-test/src/test/java/org/springframework/test/context/junit/SpringJUnitJupiterTestSuite.java

@@ -18,6 +18,7 @@ package org.springframework.test.context.junit;
 
 import org.junit.platform.runner.JUnitPlatform;
 import org.junit.platform.suite.api.ExcludeTags;
+import org.junit.platform.suite.api.IncludeClassNamePatterns;
 import org.junit.platform.suite.api.IncludeEngines;
 import org.junit.platform.suite.api.SelectPackages;
 import org.junit.platform.suite.api.UseTechnicalNames;
@@ -48,6 +49,7 @@ import org.junit.runner.RunWith;
 @RunWith(JUnitPlatform.class)
 @IncludeEngines("junit-jupiter")
 @SelectPackages("org.springframework.test.context.junit.jupiter")
+@IncludeClassNamePatterns(".*Tests$")
 @ExcludeTags("failing-test-case")
 @UseTechnicalNames
 public class SpringJUnitJupiterTestSuite {

spring-test/src/test/java/org/springframework/test/context/junit/jupiter/parallel/ParallelExecutionSpringExtensionTests.java

@@ -0,0 +1,89 @@
+/*
+ * Copyright 2002-2018 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
+ *
+ *      http://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.test.context.junit.jupiter.parallel;
+
+import java.lang.reflect.Parameter;
+
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.RepeatedTest;
+import org.junit.platform.launcher.Launcher;
+import org.junit.platform.launcher.LauncherDiscoveryRequest;
+import org.junit.platform.launcher.core.LauncherFactory;
+import org.junit.platform.launcher.listeners.SummaryGeneratingListener;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.ApplicationContext;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.test.context.junit.jupiter.SpringJUnitConfig;
+
+import static org.junit.jupiter.api.Assertions.*;
+import static org.junit.jupiter.engine.Constants.*;
+import static org.junit.platform.engine.discovery.DiscoverySelectors.*;
+import static org.junit.platform.launcher.core.LauncherDiscoveryRequestBuilder.*;
+
+/**
+ * Integration tests which verify that {@code @BeforeEach} and {@code @AfterEach} methods
+ * that accept {@code @Autowired} arguments can be executed in parallel without issues
+ * regarding concurrent access to the {@linkplain Parameter parameters} of such methods.
+ *
+ * @author Sam Brannen
+ * @since 5.1.3
+ */
+class ParallelExecutionSpringExtensionTests {
+
+	private static final int NUM_TESTS = 1000;
+
+	@RepeatedTest(10)
+	void runTestsInParallel() {
+		Launcher launcher = LauncherFactory.create();
+		SummaryGeneratingListener listener = new SummaryGeneratingListener();
+		launcher.registerTestExecutionListeners(listener);
+
+		LauncherDiscoveryRequest request = request()//
+				.configurationParameter(PARALLEL_EXECUTION_ENABLED_PROPERTY_NAME, "true")//
+				.configurationParameter(PARALLEL_CONFIG_DYNAMIC_FACTOR_PROPERTY_NAME, "10")//
+				.selectors(selectClass(TestCase.class))//
+				.build();
+
+		launcher.execute(request);
+
+		assertEquals(NUM_TESTS, listener.getSummary().getTestsSucceededCount(),
+				"number of tests executed successfully");
+	}
+
+	@SpringJUnitConfig
+	static class TestCase {
+
+		@BeforeEach
+		void beforeEach(@Autowired ApplicationContext context) {
+		}
+
+		@RepeatedTest(NUM_TESTS)
+		void repeatedTest(@Autowired ApplicationContext context) {
+		}
+
+		@AfterEach
+		void afterEach(@Autowired ApplicationContext context) {
+		}
+
+		@Configuration
+		static class Config {
+		}
+	}
+
+}