Gradle 6 Junit 5 测试错误

在使用 Gradle 进行 build 的时候运行测试，提示 build 不能完成，测试不能进行。

错误信息：

Caused by: org.junit.platform.commons.PreconditionViolationException: Cannot create Launcher without at least one TestEngine; consider adding an engine implementation JAR to the classpath

org.gradle.api.internal.tasks.testing.TestSuiteExecutionException: Could not complete execution for Gradle Test Executor 19.
	at org.gradle.api.internal.tasks.testing.SuiteTestClassProcessor.stop(SuiteTestClassProcessor.java:63)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:566)
	at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:36)
	at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24)
	at org.gradle.internal.dispatch.ContextClassLoaderDispatch.dispatch(ContextClassLoaderDispatch.java:33)
	at org.gradle.internal.dispatch.ProxyDispatchAdapter$DispatchingInvocationHandler.invoke(ProxyDispatchAdapter.java:94)
	at com.sun.proxy.$Proxy2.stop(Unknown Source)
	at org.gradle.api.internal.tasks.testing.worker.TestWorker.stop(TestWorker.java:132)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:566)
	at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:36)
	at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24)
	at org.gradle.internal.remote.internal.hub.MessageHubBackedObjectConnection$DispatchWrapper.dispatch(MessageHubBackedObjectConnection.java:182)
	at org.gradle.internal.remote.internal.hub.MessageHubBackedObjectConnection$DispatchWrapper.dispatch(MessageHubBackedObjectConnection.java:164)
	at org.gradle.internal.remote.internal.hub.MessageHub$Handler.run(MessageHub.java:412)
	at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:64)
	at org.gradle.internal.concurrent.ManagedExecutorImpl$1.run(ManagedExecutorImpl.java:48)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
	at org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:56)
	at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: org.junit.platform.commons.PreconditionViolationException: Cannot create Launcher without at least one TestEngine; consider adding an engine implementation JAR to the classpath
	at org.junit.platform.commons.util.Preconditions.condition(Preconditions.java:296)
	at org.junit.platform.launcher.core.DefaultLauncher.<init>(DefaultLauncher.java:58)
	at org.junit.platform.launcher.core.LauncherFactory.create(LauncherFactory.java:91)
	at org.junit.platform.launcher.core.LauncherFactory.create(LauncherFactory.java:67)
	at org.gradle.api.internal.tasks.testing.junitplatform.JUnitPlatformTestClassProcessor$CollectAllTestClassesExecutor.processAllTestClasses(JUnitPlatformTestClassProcessor.java:97)
	at org.gradle.api.internal.tasks.testing.junitplatform.JUnitPlatformTestClassProcessor$CollectAllTestClassesExecutor.access$000(JUnitPlatformTestClassProcessor.java:79)
	at org.gradle.api.internal.tasks.testing.junitplatform.JUnitPlatformTestClassProcessor.stop(JUnitPlatformTestClassProcessor.java:75)
	at org.gradle.api.internal.tasks.testing.SuiteTestClassProcessor.stop(SuiteTestClassProcessor.java:61)
	... 25 more
Wrap lines

这里有关 Junit 5 进行 Gradle 配置的时候需要配置测试引擎。

请参考下面的链接中的说明：

https://docs.gradle.org/current/userguide/java_testing.html#using_junit5

首先你需要在你的依赖中添加下面的内容：

testImplementation 'org.junit.jupiter:junit-jupiter-api:5.6.1'
testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine:5.6.1'

同时，如果你使用的是 Junit 5 的话，你还需要指定测试：

test {
    useJUnitPlatform()
}

如果你这里不指定这个 test 测试的话，你项目的测试是不会运行的。

https://www.cwiki.us/display/GradleZH/questions/57938645