plugin-under-test-metadata.properties not created by Gradle TestKit when running tests in IDEA

Question

I am using Gradle 3.3 and trying to test a custom plugin with JUnit and Gradle TestKit. In plugin's build.gradle I have

version '0.1'

apply plugin: 'groovy'
apply plugin: 'java-gradle-plugin'

sourceCompatibility = 1.8

repositories {
    mavenCentral()
}

dependencies {
    compile project(':codegen-core')
    compile localGroovy()
    testCompile 'junit:junit:4.12'
}

The test is

package com.huawei.odmf.codegen.gradle

import org.gradle.testkit.runner.BuildResult
import org.gradle.testkit.runner.GradleRunner
import org.gradle.testkit.runner.TaskOutcome
import org.junit.Before
import org.junit.Rule
import org.junit.Test
import org.junit.rules.TemporaryFolder

import static org.junit.Assert.*

class TestOdmfCodegenPlugin {

    @Rule 
    public final TemporaryFolder testProjectDir = new TemporaryFolder()

    private File buildFile
    private File assetsDir

    @Before
    void setUp() {
        buildFile = testProjectDir.newFile("build.gradle")
        assetsDir = testProjectDir.newFolder("src", "main", "assets")
    }

    @Test
    void testPlugin() {
        buildFile << """
          plugins {
          id 'com.huawei.odmf'
        }

        apply plugin: 'com.android.application'

        odmf {
            modelFile 'odmf.xml'
        }
        """

        BuildResult result = GradleRunner.create().
                withProjectDir(testProjectDir.root).
                withArguments(OdmfCodegenPlugin.taskName).
                withPluginClasspath().
                build()

        // assertions
    }
}

Under src/main/resources/META-INF/gradle-plugins/com.huawei.odmf.properties I have

implementation-class=com.huawei.odmf.codegen.gradle.OdmfCodegenPlugin

This seems to be all that's required according to https://docs.gradle.org/current/userguide/test_kit.html#sub:test-kit-automatic-classpath-injection and the automaticClasspathInjectionQuickstart sample.

However, this test fails at withPluginClasspath() (EDIT: when run in IDEA; it works from command line) with the following stack trace (to my understanding, plugin-under-test-metadata.properties is supposed to be created by java-gradle-plugin automatically):

org.gradle.testkit.runner.InvalidPluginMetadataException: Test runtime classpath does not contain plugin metadata file 'plugin-under-test-metadata.properties'

    at org.gradle.testkit.runner.internal.PluginUnderTestMetadataReading.readImplementationClasspath(PluginUnderTestMetadataReading.java:44)
    at org.gradle.testkit.runner.internal.PluginUnderTestMetadataReading.readImplementationClasspath(PluginUnderTestMetadataReading.java:37)
    at org.gradle.testkit.runner.internal.DefaultGradleRunner.withPluginClasspath(DefaultGradleRunner.java:146)
    at org.gradle.testkit.runner.internal.DefaultGradleRunner$withPluginClasspath$0.call(Unknown Source)
    at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:48)
    at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:113)
    at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:117)
    at com.huawei.odmf.codegen.gradle.TestOdmfCodegenPlugin.testPlugin(TestOdmfCodegenPlugin.groovy:40)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
    at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
    at org.junit.rules.ExternalResource$1.evaluate(ExternalResource.java:48)
    at org.junit.rules.RunRules.evaluate(RunRules.java:20)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
    at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:51)
    at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
    at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)

What am I missing?

Answer 1

In Gradle 4, I was trying to use gradleTestKit() and got this error.

• adding the below plugin fixed it.

plugins {
    id 'java-gradle-plugin'
}