Add support for latest AGP 3.2.0 alpha versions (#70)

* Support changes to VariantType API in AGP 3.2.0-alpha06
* Update accessor for Java output directories for AGP 3.2.0-alpha04+06 support

Author: Marcel Schnelle

android-junit5-tests/src/test/kotlin/de/mannodermaus/gradle/plugins/junit5/PluginSpec.kt

@@ -578,15 +578,36 @@ class PluginSpec : Spek({
           context("using custom exclusion rules") {
             val project by memoized { testProjectBuilder.build() }
 
-            // Create some fake class files to verify the Jacoco tree
+            // Create some fake files to verify the Jacoco tree
             beforeEachTest {
-              project.file("build/intermediates/classes/debug").mkdirs()
-              project.file("build/intermediates/classes/debug/R.class").createNewFile()
-              project.file("build/intermediates/classes/debug/FirstFile.class").createNewFile()
-              project.file("build/intermediates/classes/debug/SecondFile.class").createNewFile()
-              project.file("build/intermediates/classes/release").mkdirs()
-              project.file("build/intermediates/classes/release/R.class").createNewFile()
-              project.file("build/intermediates/classes/release/SecondFile.class").createNewFile()
+              // Since the location of intermediate class files changed in different
+              // versions of the Android Gradle Plugin,
+              // create each class file in multiple directories to remain compatible with all approaches
+              listOf(
+                  // AGP 3.2.0-alpha06 and above
+                  "build/intermediates/artifact_transform/compileDebugJavaWithJavac/classes",
+                  // AGP 3.2.0-alpha04 and above
+                  "build/intermediates/artifact_transform/javac/debug/classes",
+                  // Everything below
+                  "build/intermediates/classes/debug").forEach { folder ->
+                project.file(folder).mkdirs()
+                project.file("$folder/R.class").createNewFile()
+                project.file("$folder/FirstFile.class").createNewFile()
+                project.file("$folder/SecondFile.class").createNewFile()
+              }
+
+              listOf(
+                  // AGP 3.2.0-alpha06 and above
+                  "build/intermediates/artifact_transform/compileReleaseJavaWithJavac/classes",
+                  // AGP 3.2.0-alpha04 and above
+                  "build/intermediates/artifact_transform/javac/release/classes",
+                  // Everything below
+                  "build/intermediates/classes/release").forEach { folder ->
+                project.file(folder).mkdirs()
+                project.file("$folder/R.class").createNewFile()
+                project.file("$folder/SecondFile.class").createNewFile()
+              }
+
               project.file("src/main/java").mkdirs()
               project.file("src/main/java/OkFile.java").createNewFile()
               project.file("src/main/java/AnnoyingFile.java").createNewFile()

android-junit5/build.gradle

@@ -79,9 +79,14 @@ dependencies {
   implementation "org.codehaus.groovy:groovy:$GROOVY_VERSION"
   implementation "org.jetbrains.kotlin:kotlin-stdlib:$KOTLIN_VERSION"
 
-  // Dependent Plugins
+  // Other Dependencies
+  implementation "com.annimon:stream:$STREAMS_BACKPORT_VERSION"
+
+  // JUnit Platform
   implementation "org.junit.platform:junit-platform-console:$JUNIT_PLATFORM_VERSION"
   implementation "org.junit.platform:junit-platform-commons:$JUNIT_PLATFORM_VERSION"
+
+  // Dependent Plugins
   implementation "com.android.tools.build:gradle:$ANDROID_PLUGIN_VERSION"
   compileOnly "org.jetbrains.kotlin:kotlin-gradle-plugin:$KOTLIN_VERSION"
 }

android-junit5/src/main/groovy/de/mannodermaus/gradle/plugins/junit5/GroovyInterop.groovy

@@ -4,20 +4,43 @@ import com.android.annotations.NonNull
 import com.android.build.gradle.api.BaseVariant
 import com.android.build.gradle.internal.scope.VariantScope
 import com.android.build.gradle.internal.variant.BaseVariantData
+import com.annimon.stream.Optional
 
 /**
  * Utility functions exposed to Kotlin consumers
- * that can't safely access Groovy members otherwise.*/
+ * that can't safely access Groovy members otherwise,
+ * or require reflection to access in a compatible manner
+ * across all supported versions of the Android Gradle Plugin.*/
 class GroovyInterop {
 
+  //   Access to UNIT_TEST was moved from VariantType to VariantTypeImpl in AGP 3.2.0-alpha06
+  private static final def VariantType =
+      reflectiveClass("com.android.builder.core.VariantTypeImpl")
+          .or { reflectiveClass("com.android.builder.core.VariantType") }
+  // Java outputs are accessed through this enum in AGP 3.2.0-alpha02
+  private static final def InternalArtifactType =
+      reflectiveClass("com.android.build.gradle.internal.scope.InternalArtifactType")
+
   // No instances
   private GroovyInterop() { throw new AssertionError() }
 
+  /**
+   * Attempts to look up a Class based on its FQCN, returns an empty Optional if this fails
+   * @param fqcn Fully qualified class name
+   * @return The class, or an empty Optional
+   */
+  private static Optional<Class> reflectiveClass(String fqcn) {
+    try {
+      return Optional.of(Class.forName(fqcn))
+    } catch (ignored) {
+      return Optional.empty()
+    }
+  }
+
   /**
    * Obtains the VariantData of the provided Variant.
-   * BaseVariant#variantData is protected
-   * and can't be accessed through Kotlin directly.
    *
+   * @because 'BaseVariant.variantData' is protected and can't be accessed through Kotlin directly
    * @param variant Variant to retrieve the scope of
    * @return The scope
    */
@@ -28,18 +51,60 @@ class GroovyInterop {
 
   /**
    * Obtains the Java output directory of the provided VariantScope in a safe manner.
-   * In Android Gradle Plugin 3.2.0-alpha02, the original method was removed.
    *
+   * @because In Android Gradle Plugin 3.2.0-alpha02, the original method was removed
    * @param variant VariantScope to retrieve the Java output directory from
    * @return That file
    */
   @NonNull
-  static File variantScope_javaOutputDir(VariantScope scope) {
-    if (scope.hasProperty("javaOutputDir")) {
-      return scope.javaOutputDir
+  static Set<File> variantScope_javaOutputDirs(VariantScope scope) {
+    if (scope.hasProperty("buildArtifactsHolder") && InternalArtifactType.isPresent()) {
+      def artifactType = InternalArtifactType
+          .map { it.getDeclaredField("JAVAC").get(null) }
+          .get()
+      if (scope.buildArtifactsHolder.hasArtifact(artifactType)) {
+        // 3.2.0-alpha04 and above:
+        // Java outputs are moved into an "artifacts_transform" subdirectory
+        return scope.buildArtifactsHolder.getArtifactFiles(artifactType).files
+      } else {
+        // 3.2.0-alpha02 and above:
+        // Java outputs are still inside the "intermediates/classes" directory,
+        // but there is no public API for that, so construct the path yourself
+        return [new File(scope.globalScope.intermediatesDir,
+            "/classes/" + scope.variantConfiguration.dirName)]
+      }
     } else {
-      return new File(scope.globalScope.intermediatesDir,
-          "/classes/" + scope.variantConfiguration.dirName)
+      // Below 3.2.0-alpha02:
+      // Java outputs are expressed through the javaOutputDir property
+      return [scope.javaOutputDir]
     }
   }
+
+  /**
+   * Obtains the task name prefix for Unit Test variants.
+   *
+   * @because In Android Gradle Plugin 3.2.0-alpha06, the underlying constants on VariantType were renamed
+   * @return The unit test prefix
+   */
+  @NonNull
+  static String variantType_unitTestPrefix() {
+    return VariantType
+        .map { it.getDeclaredField("UNIT_TEST").get(null) }
+        .map { it.prefix }
+        .orElseThrow { new IllegalArgumentException("can't get VariantType.UNIT_TEST.prefix") }
+  }
+
+  /**
+   * Obtains the task name suffix for Unit Test variants.
+   *
+   * @because In Android Gradle Plugin 3.2.0-alpha06, the underlying constants on VariantType were renamed
+   * @return The unit test prefix
+   */
+  @NonNull
+  static String variantType_unitTestSuffix() {
+    return VariantType
+        .map { it.getDeclaredField("UNIT_TEST").get(null) }
+        .map { it.suffix }
+        .orElseThrow { new IllegalArgumentException("can't get VariantType.UNIT_TEST.suffix") }
+  }
 }

android-junit5/src/main/kotlin/de/mannodermaus/gradle/plugins/junit5/Interop.kt

@@ -16,11 +16,18 @@ import java.io.File
 val BaseVariant.variantData: BaseVariantData
   get() = GroovyInterop.baseVariant_variantData(this)
 
-val VariantScope.safeJavaOutputDir: File
-  get() = GroovyInterop.variantScope_javaOutputDir(this)
+val VariantScope.safeJavaOutputDirs: Set<File>
+  get() = GroovyInterop.variantScope_javaOutputDirs(this)
 
 /* Types */
 
+class VariantTypeCompat {
+  companion object {
+    val UNIT_TEST_PREFIX = GroovyInterop.variantType_unitTestPrefix()
+    val UNIT_TEST_SUFFIX = GroovyInterop.variantType_unitTestSuffix()
+  }
+}
+
 /**
  * Multi-language functional construct with no parameters,
  * mapped to Groovy's dynamic Closures as well as Kotlin's invoke syntax.

android-junit5/src/main/kotlin/de/mannodermaus/gradle/plugins/junit5/providers/Java.kt

@@ -2,7 +2,7 @@ package de.mannodermaus.gradle.plugins.junit5.providers
 
 import com.android.build.gradle.api.BaseVariant
 import de.mannodermaus.gradle.plugins.junit5.internal.unitTestVariant
-import de.mannodermaus.gradle.plugins.junit5.safeJavaOutputDir
+import de.mannodermaus.gradle.plugins.junit5.safeJavaOutputDirs
 import de.mannodermaus.gradle.plugins.junit5.variantData
 
 /**
@@ -25,5 +25,5 @@ class JavaDirectoryProvider(private val variant: BaseVariant) : DirectoryProvide
           .toSet()
 
   private fun classFoldersOf(variant: BaseVariant) =
-      setOf(variant.variantData.scope.safeJavaOutputDir)
+      variant.variantData.scope.safeJavaOutputDirs
 }

android-junit5/src/main/kotlin/de/mannodermaus/gradle/plugins/junit5/tasks/UnitTest.kt

@@ -4,9 +4,9 @@ import com.android.build.gradle.api.BaseVariant
 import com.android.build.gradle.internal.scope.TaskConfigAction
 import com.android.build.gradle.internal.scope.VariantScope
 import com.android.build.gradle.tasks.factory.AndroidUnitTest
-import com.android.builder.core.VariantType
 import de.mannodermaus.gradle.plugins.junit5.AndroidJUnitPlatformExtension
 import de.mannodermaus.gradle.plugins.junit5.JUnit5UnitTest
+import de.mannodermaus.gradle.plugins.junit5.VariantTypeCompat
 import de.mannodermaus.gradle.plugins.junit5.internal.android
 import de.mannodermaus.gradle.plugins.junit5.internal.junit5Info
 import de.mannodermaus.gradle.plugins.junit5.junitPlatform
@@ -138,7 +138,8 @@ open class AndroidJUnit5UnitTest : JavaExec(), JUnit5UnitTest {
     /* Private */
 
     private fun getDefaultJUnit4Task(): AndroidUnitTest {
-      val name = scope.getTaskName(VariantType.UNIT_TEST.prefix, VariantType.UNIT_TEST.suffix)
+      val name = scope.getTaskName(VariantTypeCompat.UNIT_TEST_PREFIX,
+          VariantTypeCompat.UNIT_TEST_SUFFIX)
       return project.tasks.getByName(name) as AndroidUnitTest
     }
 
@@ -189,7 +190,8 @@ open class AndroidJUnit5UnitTest : JavaExec(), JUnit5UnitTest {
       variantUnitTestTask.dependsOn(task)
 
       // Require that test classes are assembled first
-      val defaultAssembleTestName = scope.getTaskName("assemble", VariantType.UNIT_TEST.suffix)
+      val defaultAssembleTestName = scope.getTaskName("assemble",
+          VariantTypeCompat.UNIT_TEST_SUFFIX)
       val defaultAssembleTask = project.tasks.getByName(defaultAssembleTestName)
       task.dependsOn(defaultAssembleTask)
 

gradle.properties

@@ -58,6 +58,7 @@ TARGET_SDK_VERSION                          = 27
 SAMPLE_MIN_SDK_VERSION                      = 14
 
 # Dependency versions
+STREAMS_BACKPORT_VERSION                    = 1.1.9
 JUNIT_PLATFORM_VERSION                      = 1.0.3
 JUNIT_JUPITER_VERSION                       = 5.0.3
 JUNIT_VINTAGE_VERSION                       = 4.12.2