Junit 配置错误：您必须为此 @ParameterizedTest 提供至少一个参数答案

【问题标题】：Junit Configuration error: You must provide at least one argument for this @ParameterizedTestJunit 配置错误：您必须为此 @ParameterizedTest 提供至少一个参数
【发布时间】：2018-05-02 09:58:31
【问题描述】：

我正在尝试借助带有 JUnit 5 的 FizzBuzz 应用程序来理解 JUnit 5。下面是一个测试用例

@DisplayName("Test for multiples of 5")
    @ParameterizedTest
    @MethodSource("multiplesOf5Inputs")
    public void multiplesOf5(Integer input){
        String result =  fizzBuzz.play(input);
        Assertions.assertEquals("Buzz",result);
    }

    private static Stream<Integer> multiplesOf5Inputs(){
        return IntStream.range(1,60)
.skip(15).skip(30).skip(45).skip(60)
                .mapToObj(i->i);
    }

由于抛出以下异常，此测试用例未能执行

org.junit.platform.commons.util.PreconditionViolationException: Configuration error: You must provide at least one argument for this @ParameterizedTest

at org.junit.platform.commons.util.Preconditions.condition(Preconditions.java:297)
at org.junit.jupiter.params.ParameterizedTestExtension.lambda$provideTestTemplateInvocationContexts$7(ParameterizedTestExtension.java:60)
at java.util.stream.AbstractPipeline.close(AbstractPipeline.java:323)
at java.util.stream.ReferencePipeline$7$1.accept(ReferencePipeline.java:271)
at java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1374)
at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481)
at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471)
at java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:151)
at java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:174)
at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
at java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:418)
at org.junit.jupiter.engine.descriptor.TestTemplateTestDescriptor.execute(TestTemplateTestDescriptor.java:101)
at org.junit.jupiter.engine.descriptor.TestTemplateTestDescriptor.execute(TestTemplateTestDescriptor.java:38)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.lambda$executeRecursively$3(HierarchicalTestExecutor.java:112)
at org.junit.platform.engine.support.hierarchical.SingleTestExecutor.executeSafely(SingleTestExecutor.java:66)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.executeRecursively(HierarchicalTestExecutor.java:108)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.execute(HierarchicalTestExecutor.java:79)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.lambda$executeRecursively$2(HierarchicalTestExecutor.java:120)
at java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:184)
at java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:175)
at java.util.Iterator.forEachRemaining(Iterator.java:116)
at java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.java:1801)
at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481)
at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471)
at java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:151)
at java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:174)
at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
at java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:418)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.lambda$executeRecursively$3(HierarchicalTestExecutor.java:120)
at org.junit.platform.engine.support.hierarchical.SingleTestExecutor.executeSafely(SingleTestExecutor.java:66)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.executeRecursively(HierarchicalTestExecutor.java:108)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.execute(HierarchicalTestExecutor.java:79)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.lambda$executeRecursively$2(HierarchicalTestExecutor.java:120)
at java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:184)
at java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:175)
at java.util.Iterator.forEachRemaining(Iterator.java:116)
at java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.java:1801)
at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481)
at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471)
at java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:151)
at java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:174)
at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
at java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:418)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.lambda$executeRecursively$3(HierarchicalTestExecutor.java:120)
at org.junit.platform.engine.support.hierarchical.SingleTestExecutor.executeSafely(SingleTestExecutor.java:66)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.executeRecursively(HierarchicalTestExecutor.java:108)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor$NodeExecutor.execute(HierarchicalTestExecutor.java:79)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:55)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestEngine.execute(HierarchicalTestEngine.java:43)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:170)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:154)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:90)
at com.intellij.junit5.JUnit5IdeaTestRunner.startRunnerWithArgs(JUnit5IdeaTestRunner.java:74)
at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)

根本原因可能是什么？

【问题讨论】：

错误似乎很明显：Configuration error: You must provide at least one argument for this @ParameterizedTest！换句话说，你的参数在哪里？

标签： java junit tdd junit5

【解决方案1】：

如果您要创建一个包含 60 个内容的流，然后跳过 60 多个内容...您的流最终会是空的。

所以你需要确保multiplesOf5Inputs() 实际上返回一个非空流。

【讨论】：

刚刚意识到这一点，并在您 8 秒后发布了答案 :) 谢谢

【解决方案2】：

问题在于我对跳过方法的理解。

我假设 skip 会跳过特定的数字，但是，它会跳过作为参数提供的元素数。

这意味着当在 60 个元素的范围内调用 .skip(60) 时，所有元素都将被跳过并且有一个空流。

因此错误

配置错误：您必须为此提供至少一个参数 @ParameterizedTest 把代码改成

 @DisplayName("Test for multiples of 5")
    @ParameterizedTest
    @MethodSource("multiplesOf5Inputs")
    public void multiplesOf5(int input){
        String result =  fizzBuzz.play(input);
        Assertions.assertEquals("Buzz",result);
    }

    private static Stream<Integer> multiplesOf5Inputs(){
        return IntStream.range(1,60)
                // You need filter, not skip
                .mapToObj(i->{return i*5;}).filter(i -> i%15!=0);
    }

总结：当源提供的参数个数为0时会出现此错误

【讨论】：

我的意见是应该允许一组空的参数（它在junit 4中）。这发生在我的软件中，其中的参数非常受数据驱动。没有参数应该真的意味着没有测试，而不是测试失败。不幸的是，没有标志或注释可以防止 junit 抛出此异常。作为一种解决方法，我向集合/流添加一个空值，以便调用一次 @ParameterizedTest 方法，但如果它获得一个空参数则退出。