Gradle plugin test toolkit

Provides the function to generate a Gradle project for us to test your Gradle plugin

Table of content

• How to use
  • Compile
  • Using GradlePluginTest to use DSL to generate your test project
  • Case1 using default DSL to generate your test project
  • Case2 Mix the DSL with an existed project
  • Case3 Use the default template DSL to generate an android project
• Samples
• Code style
• FAQ
• Links

How to use

Simple setup

Compile

Kotlin

repositories {
    mavenCentral()
}
dependencies {
    testImplementation("io.github.jackchen365:gradle-test-toolkit:1.0.1")
}

Using GradlePluginTest to use DSL to generate your test project

Kotlin

class TemplatePluginTest : GradlePluginTest() {
    private fun testProjectSetup(closure: TemplatePluginTest.() -> Unit) {
        kotlinAndroidTemplate {
            template {
                plugins {
                    id("com.test.plugin").version(File("../VERSION_CURRENT.txt").readText().trim())
                }
                dependencies {
                    implementation("androidx.core:core-ktx:1.7.0")
                    implementation("androidx.appcompat:appcompat:1.4.1")
                }
            }
        }
        TemplatePluginTest().apply(closure)
    }

    @Test
    fun buildTest() {
        testProjectSetup {
            build(":app:prebuild") {
                Assertions.assertEquals(TaskOutcome.SUCCESS, task(":app:prebuild")?.outcome)
            }
            build(":app:lint") {
                Assertions.assertEquals(TaskOutcome.FAILED, task(":app:lint")?.outcome)
            }
        }
    }
}

Case1 using default DSL to generate your test project

Kotlin

androidProject {
    module("app") {
        sourceDir("com.test") {
            file("Main.kt") {
                """
                fun main(){
                    println("Hello world")
                }
                """.trimIndent()
            }
        }
    }
    settingGradle {
        """
        pluginManagement {
            repositories {
                gradlePluginPortal()
                google()
                mavenCentral()
            }
        }
        """.trimIndent()
    }
    gradleProperties { "android.useAndroidX=true" }
}

Case2 Mix the DSL with an existed project

Kotlin

androidProject("src/test/inputs/test-app") {
    module("app") {
        kotlinSourceDir("test") {
            file("Main.kt") {
                """
                fun main(){
                    println("Hello world")
                }
                """.trimIndent()
            }
        }
    }
}
Assertions.assertTrue(File(projectDir, "app/src/main/kotlin/test/Main.kt").exists())
Assertions.assertTrue(File(projectDir, "app/build.gradle").exists())

Case3 Use the default template DSL to generate an android project

Kotlin

androidTemplateKts {
    template {
        `package` {
            name = "test-app"
            packageName = "com.android.test"
        }
        build {
            targetSdk = 31
            targetSdk = 31
            minSdk = 21
        }
        properties {
            property("android.useAndroidX=true")
        }
        repositories {
            repo("google()")
            repo("mavenCentral()")
        }
        plugins {
            id("com.android.application").version(androidVersion())
            id("org.jetbrains.kotlin.android").version(kotlinVersion())
        }
        dependencies {
            implementation("androidx.core:core-ktx:1.7.0")
            implementation("androidx.appcompat:appcompat:1.4.1")
        }
    }
}

Samples

Optionally apply plugin to all project modules:

Kotlin

class TemplatePluginTest : GradlePluginTest() {

    private fun testProjectSetup(closure: TemplatePluginTest.() -> Unit) {
        kotlinAndroidTemplate {
            template {
                plugins {
                    id("com.test.plugin").version(File("../VERSION_CURRENT.txt").readText().trim())
                }
                dependencies {
                    implementation("androidx.core:core-ktx:1.7.0")
                    implementation("androidx.appcompat:appcompat:1.4.1")
                }
            }
        }
        TemplatePluginTest().apply(closure)
    }

    @Test
    fun buildTest() {
        testProjectSetup {
            build(":app:processDebugResources") {
                Assertions.assertEquals(TaskOutcome.SUCCESS, task(":app:processDebugResources")?.outcome)
            }
            build("compileDebugJavaWithJavac") {
                Assertions.assertEquals(TaskOutcome.SUCCESS, task(":app:compileDebugJavaWithJavac")?.outcome)
            }
        }
    }
}

• test-plugin - A Gradle plugin uses the test-toolkit to do the integration testing.

Code style

We use ktlint to help us format the code. You can use the tasks below to check your code before commit

addKtlintCheckGitPreCommitHook - adds Git pre-commit hook, that runs ktlint check over staged files. addKtlintFormatGitPreCommitHook - adds Git pre-commit hook, that runs ktlint format over staged files and adds fixed files back to commit.

FAQ

• Why we need it?

  It's tough to test the Gradle plugin and especially with Gradle 7.0. When we use gradleTestKit() we are facing several problem.

  • Can not debug the Gradle plugin

      GradleRunner.create()
        .withProjectDir(projectDir)
        .withGradleVersion(gradleVersion)
        .withDebug(true)
        .forwardOutput()

    • Can not load the kotlin and android build-tool(The class in different class loader.)

      FAILURE: Build failed with an exception.
      
      * What went wrong:
        com/android/build/gradle/AppExtension
      > com.android.build.gradle.AppExtension
      * Try:
      Run with --info or --debug option to get more log output. Run with --scan to get full insights.
      * Exception is:
         java.lang.NoClassDefFoundError: com/android/build/gradle/AppExtension
         at com.github.jackchen.test.gradle.plugin.TemplatePlugin.apply(TemplatePlugin.kt:15)
         at com.github.jackchen.test.gradle.plugin.TemplatePlugin.apply(TemplatePlugin.kt:7)
      ...
      

    • We may need a simple repo for us to test.

Links

Ktlint Gradle Plugin on the Gradle Plugin Registry

License

Copyright 2022 JackChen

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.