Merge pull request #28 from austinarbor/test-kit-coverage

Test Kit Coverage

gradle/libs.versions.toml

@@ -2,6 +2,7 @@
 assertj = "3.24.2"
 detekt = "1.23.1"
 gradle-publish = "1.2.1"
+jacoco = "0.8.10"
 junit = "5.10.0"
 kotlin = "1.9.10"
 maven = "3.9.4"
@@ -14,6 +15,7 @@ tomlj = "1.1.0"
 [libraries]
 assertj = { group = "org.assertj", name = "assertj-core", version.ref = "assertj" }
 detekt-formatting = { group = "io.gitlab.arturbosch.detekt", name = "detekt-formatting", version.ref = "detekt" }
+jacoco-agent = { group = "org.jacoco", name = "org.jacoco.agent", version.ref = "jacoco" }
 maven-model = { group = "org.apache.maven", name = "maven-model", version.ref = "maven" }
 mockito-core = { group = "org.mockito", name = "mockito-core", version.ref = "mockito" }
 mockito-junit-jupiter = { group = "org.mockito", name = "mockito-junit-jupiter", version.ref = "mockito" }

plugin/build.gradle.kts

@@ -22,6 +22,8 @@ val PLUGIN_DESCRIPTION: String by project
 group = GROUP_ID
 version = VERSION
 
+val jacocoRuntime by configurations.creating
+
 repositories {
     mavenCentral()
 }
@@ -35,6 +37,14 @@ dependencies {
     testImplementation(libs.bundles.testing)
     testImplementation(libs.bundles.mockito)
     testImplementation(gradleTestKit())
+    testRuntimeOnly(files("$buildDir/testkit"))
+    jacocoRuntime(variantOf(libs.jacoco.agent) {
+        classifier("runtime")
+    })
+}
+
+jacoco {
+    toolVersion = libs.versions.jacoco.get()
 }
 
 spotless {
@@ -104,8 +114,31 @@ publishing {
     }
 }
 
+// creates files in build/testkit that we use in
+// VersionCatalogGeneratorPluginTest to instrument
+// the Testkit runner with jacoco so we get test
+// coverage output
+val createTestkitFiles by tasks.registering {
+    val outputDir = file("${buildDir}/testkit")
+    inputs.files(sourceSets.main.get().runtimeClasspath)
+    inputs.files(jacocoRuntime)
+    outputs.dir(outputDir)
+    doLast {
+        outputDir.mkdirs()
+        val jacocoPath = jacocoRuntime.asPath.replace('\\', '/')
+        file("$outputDir/testkit-classpath.txt")
+            .writeText(
+                sourceSets.main.get().runtimeClasspath.joinToString("\n")
+            )
+        file("$outputDir/testkit-gradle.properties").writeText(
+            "org.gradle.jvmargs=-javaagent:${jacocoPath}=destfile=$buildDir/jacoco/test.exec"
+        )
+    }
+}
+
 tasks {
     test {
+        dependsOn(createTestkitFiles)
         finalizedBy(jacocoTestReport) // report is always generated after tests run
     }
     jacocoTestReport {

plugin/src/test/kotlin/dev/aga/gradle/versioncatalogs/VersionCatalogGeneratorPluginTest.kt

@@ -3,6 +3,7 @@ package dev.aga.gradle.versioncatalogs
 import java.io.File
 import org.assertj.core.api.Assertions.assertThat
 import org.gradle.testkit.runner.GradleRunner
+import org.junit.jupiter.api.BeforeEach
 import org.junit.jupiter.api.Test
 import org.junit.jupiter.api.io.TempDir
 
@@ -11,14 +12,34 @@ class VersionCatalogGeneratorPluginTest {
 
     private val buildFile by lazy { projectDir.resolve("build.gradle.kts") }
     private val settingsFile by lazy { projectDir.resolve("settings.gradle.kts") }
+    private val propertiesFile by lazy { projectDir.resolve("gradle.properties") }
+
+    private lateinit var classpathString: String
+
+    @BeforeEach
+    fun setup() {
+        // create the classpath string which we use in the buildscript in the test build file
+        val classpathFiles = getResourceAsText("testkit-classpath.txt").lines().map { File(it) }
+
+        classpathString =
+            classpathFiles
+                .map { it.absolutePath.replace('\\', '/') }
+                .joinToString(",") { "\"$it\"" }
+        // copy the generated properties file into the runner's directory
+        propertiesFile.writeText(getResourceAsText("testkit-gradle.properties"))
+    }
 
     @Test
     fun `plugin usage succeeds`() {
         // Set up the test build
         settingsFile.writeText(
             """
             import dev.aga.gradle.versioncatalogs.Generator.generate
-            
+            buildscript {
+              dependencies {
+                classpath(files($classpathString))
+              }
+            }
             plugins {
                 id("dev.aga.gradle.version-catalog-generator")
             }
@@ -56,4 +77,10 @@ class VersionCatalogGeneratorPluginTest {
 
         assertThat(result.output).contains("BUILD SUCCESSFUL")
     }
+
+    companion object {
+        private fun getResourceAsText(name: String): String {
+            return javaClass.classLoader.getResource(name).readText()
+        }
+    }
 }