JUnit 5 参数化测试 - 'Cannot invoke non-static method' in @MethodSource with Kotlin

Question

期待

将标准 JUnit 5 测试转换为参数化测试，以便使用 Kotlin 中的 @ParamterizedTest 和 @MethodSource 注释遍历测试用例流。

观察

@MethodSource 无法访问数据流。这似乎是此注释的一个问题，因为 @ValueSource(strings = ["SF", "NYC"]) 按预期遍历静态定义的选项。

错误：

PreconditionViolationException: Cannot invoke non-static method {someMethodName} on a null target.

实施

参数化测试设置为传递数据流类类似于 Phillip Hauer 在 Data Classes for Parameterized Tests.

中概述的设置

代码

build.gradle (:SomeProject)

dependencies {
    ...    
    classpath("de.mannodermaus.gradle.plugins:android-junit5:$junit5_version")
}

build.gradle (:someModule)

apply plugin: "de.mannodermaus.android-junit5"
android {
    ...
    compileOptions.targetCompatibility = JavaVersion.VERSION_1_8
    kotlinOptions.jvmTarget = "1.8"
}
dependencies {
    testImplementation "org.junit.jupiter:junit-jupiter-api:5.6.2"
    testRuntimeOnly "org.junit.jupiter:junit-jupiter-engine:5.6.2"
    testImplementation "org.junit.jupiter:junit-jupiter-params:5.6.2"
}

SomeTest.kt

class SomeTest {
    private val testDispatcher = TestCoroutineDispatcher()

    private fun someDataStates() = Stream.of(
        // Kotlin data class
        TestState("123"),
        TestState("345")
    )

    @ParameterizedTest
    @MethodSource("someDataStates")
    fun someTest(testState: TestState) = testDispatcher.runBlockingTest {
        // Test state here.
        ...
    }
}

搭建环境

Android Studio 4.0
构建 #AI-193.6911.18.40.6514223，构建于 2020 年 5 月 20 日
运行时版本：1.8.0_242-release-1644-b3-6222593 x86_64
VM：JetBrains 的 OpenJDK 64 位服务器 VM s.r.o
macOS 10.15.5
GC: ParNew, ConcurrentMarkSweep
内存：1979M
核心数：16
注册表：ide.new.welcome.screen.force=true
非捆绑插件：cn.wjdghd.unique.plugin.id、com.android.tool.sizereduction.plugin、com.developerphil.adbidea、com.thoughtworks.gauge、mobi.hsz.idea.gitignore

尝试过的解决方案

1。将测试用例数据状态重构为顶级函数。

TestCases.kt

fun someDataStates() = Stream.of(
    TestState("123"),
    TestState("345")
)

SomeTest.kt

private fun SomeDataStates() = someDataStates()

@ParameterizedTest
@MethodSource("SomeDataStates")
fun someTest(testState: TestState) = testDispatcher.runBlockingTest {
   // Test state here.
   ...

}

2。将测试用例数据状态重构为 `List` 类型的顶级函数，而不是 `Stream`.

fun someDataStates() = listOf(
    TestState("123"),
    TestState("345")
)

完整的错误日志

org.junit.platform.commons.PreconditionViolationException: Cannot invoke non-static method [private final {someMethodName} on a null target.

at org.junit.platform.commons.util.Preconditions.condition(Preconditions.java:296) at org.junit.platform.commons.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:682) at org.junit.jupiter.params.provider.MethodArgumentsProvider.lambda$provideArguments(MethodArgumentsProvider.java:46) at java.util.stream.ReferencePipeline.accept(ReferencePipeline.java:193) at java.util.stream.ReferencePipeline.accept(ReferencePipeline.java:193) at java.util.Spliterators$ArraySpliterator.forEachRemaining(Spliterators.java:948) at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:482) at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:472) at java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:150) at java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:173) at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234) at java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:485) at java.util.stream.ReferencePipeline.accept(ReferencePipeline.java:272) at java.util.stream.ReferencePipeline.accept(ReferencePipeline.java:193) at java.util.stream.ReferencePipeline.accept(ReferencePipeline.java:193) at java.util.stream.ReferencePipeline.accept(ReferencePipeline.java:193) at java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1382) at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:482) at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:472) at java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:150) at java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:173) at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234) at java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:485) at java.util.stream.ReferencePipeline.accept(ReferencePipeline.java:272) at java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1382) at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:482) at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:472) at java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:150) at java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:173) at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234) at java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:485) at org.junit.jupiter.engine.descriptor.TestTemplateTestDescriptor.execute(TestTemplateTestDescriptor.java:106) at org.junit.jupiter.engine.descriptor.TestTemplateTestDescriptor.execute(TestTemplateTestDescriptor.java:41) at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively(NodeTestTask.java:135) at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73) at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively(NodeTestTask.java:125) at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:135) at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively(NodeTestTask.java:123) at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73) at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:122) at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:80) at java.util.ArrayList.forEach(ArrayList.java:1257) at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38) at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively(NodeTestTask.java:139) at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73) at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively(NodeTestTask.java:125) at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:135) at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively(NodeTestTask.java:123) at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73) at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:122) at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:80) at java.util.ArrayList.forEach(ArrayList.java:1257) at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38) at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively(NodeTestTask.java:139) at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73) at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively(NodeTestTask.java:125) at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:135) at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively(NodeTestTask.java:123) at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73) at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:122) at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:80) at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.submit(SameThreadHierarchicalTestExecutorService.java:32) at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:57) at org.junit.platform.engine.support.hierarchical.HierarchicalTestEngine.execute(HierarchicalTestEngine.java:51) at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:248) at org.junit.platform.launcher.core.DefaultLauncher.lambda$execute(DefaultLauncher.java:211) at org.junit.platform.launcher.core.DefaultLauncher.withInterceptedStreams(DefaultLauncher.java:226) at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:199) at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:132) at com.intellij.junit5.JUnit5IdeaTestRunner.startRunnerWithArgs(JUnit5IdeaTestRunner.java:69) at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:33) at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:230) at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:58) Suppressed: org.junit.platform.commons.PreconditionViolationException: Configuration error: You must configure at least one set of arguments for this @ParameterizedTest at org.junit.platform.commons.util.Preconditions.condition(Preconditions.java:281) at org.junit.jupiter.params.ParameterizedTestExtension.lambda$provideTestTemplateInvocationContexts(ParameterizedTestExtension.java:90) at java.util.stream.AbstractPipeline.close(AbstractPipeline.java:323) at java.util.stream.ReferencePipeline.accept(ReferencePipeline.java:279) ... 49 more

Process finished with exit code 255

Answer 1

我猜你错过了告诉 JUnit 实例化你的测试 class 一次的信息，如下所示：

import org.junit.jupiter.api.TestInstance
import org.junit.jupiter.api.TestInstance.Lifecycle.PER_CLASS

@TestInstance(PER_CLASS) // <--- This one will do the trick
class SomeTest {

    private val testDispatcher = TestCoroutineDispatcher()

    @ParameterizedTest
    @MethodSource("someDataStates")
    fun someTest(testState: TestState) = testDispatcher.runBlockingTest {
        // Test state here.
        ...
    }

    private fun someDataStates() = listOf(
        TestState("123"),
        TestState("345")
    )
}

Answer 2

使用 @TestInstance(PER_CLASS)，您可能会遇到麻烦，例如，当您尝试验证某个函数已被 mockito 或 mockk 调用 X 次时。您必须汇总所有来电。

在这种情况下，使用 @JvmStatic :

class SomeTest {

    companion object{
        @JvmStatic
        private fun someDataStates() = listOf(
            TestState("123"),
            TestState("345")
        )
    }
    
    private val testDispatcher = TestCoroutineDispatcher()

    @ParameterizedTest
    @MethodSource("someDataStates")
    fun someTest(testState: TestState) = testDispatcher.runBlockingTest {
        // Test state here.
        ...
    }
}

编辑 27/08/2021： 自最新版本的 kotlin（使用 1.5.21 测试）以来，请勿将 @JvmStatic 方法设置为 private 或它会再次以 PreconditionViolationException

结束

Answer 3

如果由于某种原因您不能使用 @TestInstance(PER_CLASS) 注释，您可以在测试方法上使用 @TestFactory 注释而不是 @ParameterizedTest 注释。

@TestFactory
Stream<DynamicTest> someTest() {
    return someDataStates().map(testState -> DynamicTest.dynamicTest(testState.getName(), () -> someTest0(testState)));
}

private void someTest0(TestState testState) {
    // Test state here.
}

private Stream<TestState> someDataStates() {
    return Stream.of(
            new TestState("123"),
            new TestState("345")
    );
}

JUnit 5 参数化测试 - 'Cannot invoke non-static method' in @MethodSource with Kotlin

JUnit 5 Parameterized Test - 'Cannot invoke non-static method' in @MethodSource with Kotlin

junit

android

kotlin

android-testing

junit5

期待

观察

实施

代码

搭建环境

尝试过的解决方案

1。将测试用例数据状态重构为顶级函数。

2。将测试用例数据状态重构为 `List` 类型的顶级函数，而不是 `Stream`.

完整的错误日志

JUnit 5 参数化测试 - 'Cannot invoke non-static method' in @MethodSource with Kotlin

JUnit 5 Parameterized Test - 'Cannot invoke non-static method' in @MethodSource with Kotlin

junit

android

kotlin

android-testing

junit5

期待

观察

实施

代码

搭建环境

尝试过的解决方案

1。将测试用例数据状态重构为顶级函数。

2。将测试用例数据状态重构为 List 类型的顶级函数，而不是 Stream.

完整的错误日志

2。将测试用例数据状态重构为 `List` 类型的顶级函数，而不是 `Stream`.