Sets up jacoco coverage with a combined report and a GHA (#1303)

* Uses jacoco coverage reporting in AGP

.github/workflows/Build.yaml

@@ -17,6 +17,7 @@ jobs:
 
     permissions:
       contents: write
+      pull-requests: write
 
     timeout-minutes: 60
 
@@ -100,12 +101,13 @@ jobs:
           commit_message: "🤖 Updates screenshots"
 
       # Run local tests after screenshot tests to avoid wrong UP-TO-DATE. TODO: Ignore screenshots.
-      - name: Run local tests
+      - name: Run local tests and create report
         if: always()
         run: ./gradlew testDemoDebug :lint:test
       # Replace task exclusions with `-Pandroidx.baselineprofile.skipgeneration` when
       # https://android-review.googlesource.com/c/platform/frameworks/support/+/2602790 landed in a
       # release build
+
       - name: Build all build type and flavor permutations
         run: ./gradlew :app:assemble :benchmarks:assemble
           -x pixel6Api33ProdNonMinifiedReleaseAndroidTest
@@ -119,11 +121,11 @@ jobs:
           name: APKs
           path: '**/build/outputs/apk/**/*.apk'
 
-      - name: Upload test results (XML)
+      - name: Upload JVM local results (XML)
         if: always()
         uses: actions/upload-artifact@v4
         with:
-          name: test-results
+          name: local-test-results
           path: '**/build/test-results/test*UnitTest/**.xml'
 
       - name: Check lint
@@ -180,10 +182,7 @@ jobs:
       - name: Setup Gradle
         uses: gradle/gradle-build-action@v3
 
-      - name: Build projects before running emulator
+      - name: Build projects and run instrumentation tests
-        run: ./gradlew packageDemoDebug packageDemoDebugAndroidTest
-
-      - name: Run instrumentation tests
         uses: reactivecircus/android-emulator-runner@v2
         with:
           api-level: ${{ matrix.api-level }}
@@ -193,9 +192,41 @@ jobs:
           heap-size: 600M
           script: ./gradlew connectedDemoDebugAndroidTest --daemon
 
+      - name: Run local tests (including Roborazzi) for the combined coverage report (only API 30)
+        if: matrix.api-level == 30
+        # There is no need to verify Roborazzi tests to generate coverage.
+        run: ./gradlew testDemoDebugUnitTest -Proborazzi.test.verify=false # Add Prod if we ever add JVM tests for prod
+
+      # Add `createProdDebugUnitTestCoverageReport` if we ever add JVM tests for prod
+      - name: Generate coverage reports for Debug variants (only API 30)
+        if: matrix.api-level == 30
+        run: ./gradlew createDemoDebugCombinedCoverageReport
+        
       - name: Upload test reports
         if: always()
         uses: actions/upload-artifact@v4
         with:
           name: test-reports-${{ matrix.api-level }}
           path: '**/build/reports/androidTests'
+
+      - name: Display local test coverage (only API 30)
+        if: matrix.api-level == 30
+        id: jacoco
+        uses: madrapps/jacoco-report@v1.6.1
+        with:
+          title: Combined test coverage report
+          min-coverage-overall: 40
+          min-coverage-changed-files: 60
+          paths: |
+            ${{ github.workspace }}/**/build/reports/jacoco/**/*Report.xml
+          token: ${{ secrets.GITHUB_TOKEN }}
+        
+      - name: Upload local coverage reports (XML + HTML) (only API 30)
+        if: matrix.api-level == 30
+        uses: actions/upload-artifact@v4
+        with:
+          name: coverage-reports
+          if-no-files-found: error
+          compression-level: 1
+          overwrite: false
+          path: '**/build/reports/jacoco/'

app/build.gradle.kts

@@ -21,7 +21,6 @@ plugins {
     alias(libs.plugins.nowinandroid.android.application.flavors)
     alias(libs.plugins.nowinandroid.android.application.jacoco)
     alias(libs.plugins.nowinandroid.android.hilt)
-    id("jacoco")
     alias(libs.plugins.nowinandroid.android.application.firebase)
     id("com.google.android.gms.oss-licenses-plugin")
     alias(libs.plugins.baselineprofile)

build-logic/convention/src/main/kotlin/AndroidApplicationJacocoConventionPlugin.kt

@@ -15,6 +15,7 @@
  */
 
 import com.android.build.api.variant.ApplicationAndroidComponentsExtension
+import com.android.build.gradle.internal.dsl.BaseAppModuleExtension
 import com.google.samples.apps.nowinandroid.configureJacoco
 import org.gradle.api.Plugin
 import org.gradle.api.Project
@@ -23,13 +24,15 @@ import org.gradle.kotlin.dsl.getByType
 class AndroidApplicationJacocoConventionPlugin : Plugin<Project> {
     override fun apply(target: Project) {
         with(target) {
-            with(pluginManager) {
+            pluginManager.apply("jacoco")
-                apply("org.gradle.jacoco")
+            val androidExtension = extensions.getByType<BaseAppModuleExtension>()
-                apply("com.android.application")
+
+            androidExtension.buildTypes.configureEach {
+                enableAndroidTestCoverage = true
+                enableUnitTestCoverage = true
             }
-            val extension = extensions.getByType<ApplicationAndroidComponentsExtension>()
+
-            configureJacoco(extension)
+            configureJacoco(extensions.getByType<ApplicationAndroidComponentsExtension>())
         }
     }
-
 }

build-logic/convention/src/main/kotlin/AndroidLibraryJacocoConventionPlugin.kt

@@ -14,6 +14,8 @@
  *   limitations under the License.
  */
 
+import com.android.build.api.dsl.LibraryExtension
+import com.android.build.api.variant.ApplicationAndroidComponentsExtension
 import com.android.build.api.variant.LibraryAndroidComponentsExtension
 import com.google.samples.apps.nowinandroid.configureJacoco
 import org.gradle.api.Plugin
@@ -23,13 +25,15 @@ import org.gradle.kotlin.dsl.getByType
 class AndroidLibraryJacocoConventionPlugin : Plugin<Project> {
     override fun apply(target: Project) {
         with(target) {
-            with(pluginManager) {
+            pluginManager.apply("jacoco")
-                apply("org.gradle.jacoco")
+            val androidExtension = extensions.getByType<LibraryExtension>()
-                apply("com.android.library")
+
+            androidExtension.buildTypes.configureEach {
+                enableAndroidTestCoverage = true
+                enableUnitTestCoverage = true
             }
-            val extension = extensions.getByType<LibraryAndroidComponentsExtension>()
+
-            configureJacoco(extension)
+            configureJacoco(extensions.getByType<LibraryAndroidComponentsExtension>())
         }
     }
-
 }

build-logic/convention/src/main/kotlin/com/google/samples/apps/nowinandroid/Jacoco.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2022 The Android Open Source Project
+ * Copyright 2024 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,8 +16,13 @@
 
 package com.google.samples.apps.nowinandroid
 
+import com.android.build.api.artifact.ScopedArtifact
 import com.android.build.api.variant.AndroidComponentsExtension
+import com.android.build.api.variant.ScopedArtifacts
 import org.gradle.api.Project
+import org.gradle.api.file.Directory
+import org.gradle.api.file.RegularFile
+import org.gradle.api.provider.ListProperty
 import org.gradle.api.tasks.testing.Test
 import org.gradle.kotlin.dsl.configure
 import org.gradle.kotlin.dsl.register
@@ -32,13 +37,24 @@ private val coverageExclusions = listOf(
     "**/R.class",
     "**/R\$*.class",
     "**/BuildConfig.*",
-    "**/Manifest*.*"
+    "**/Manifest*.*",
+    "**/*_Hilt*.class",
+    "**/Hilt_*.class",
 )
 
 private fun String.capitalize() = replaceFirstChar {
     if (it.isLowerCase()) it.titlecase(Locale.getDefault()) else it.toString()
 }
 
+/**
+ * Creates a new task that generates a combined coverage report with data from local and
+ * instrumented tests.
+ *
+ * `create{variant}CombinedCoverageReport`
+ *
+ * Note that coverage data must exist before running the task. This allows us to run device
+ * tests on CI using a different Github Action or an external device farm.
+ */
 internal fun Project.configureJacoco(
     androidComponentsExtension: AndroidComponentsExtension<*, *, *>,
 ) {
@@ -46,37 +62,53 @@ internal fun Project.configureJacoco(
         toolVersion = libs.findVersion("jacoco").get().toString()
     }
 
-    val jacocoTestReport = tasks.create("jacocoTestReport")
-
     androidComponentsExtension.onVariants { variant ->
-        val testTaskName = "test${variant.name.capitalize()}UnitTest"
+        val myObjFactory = project.objects
         val buildDir = layout.buildDirectory.get().asFile
-        val reportTask = tasks.register("jacoco${testTaskName.capitalize()}Report", JacocoReport::class) {
+        val allJars: ListProperty<RegularFile> = myObjFactory.listProperty(RegularFile::class.java)
-            dependsOn(testTaskName)
+        val allDirectories: ListProperty<Directory> = myObjFactory.listProperty(Directory::class.java)
+        val reportTask =
+            tasks.register("create${variant.name.capitalize()}CombinedCoverageReport", JacocoReport::class) {
 
+                classDirectories.setFrom(
+                    allJars,
+                    allDirectories.map { dirs ->
+                        dirs.map { dir ->
+                            myObjFactory.fileTree().setDir(dir).exclude(coverageExclusions)
+                        }
+                    }
+                )
                 reports {
                     xml.required.set(true)
                     html.required.set(true)
                 }
 
-            classDirectories.setFrom(
+                // TODO: This is missing files in src/debug/, src/prod, src/demo, src/demoDebug...
-                fileTree("$buildDir/tmp/kotlin-classes/${variant.name}") {
-                    exclude(coverageExclusions)
-                }
-            )
-
                 sourceDirectories.setFrom(files("$projectDir/src/main/java", "$projectDir/src/main/kotlin"))
-            executionData.setFrom(file("$buildDir/jacoco/$testTaskName.exec"))
+
+                executionData.setFrom(
+                    project.fileTree("$buildDir/outputs/unit_test_code_coverage/${variant.name}UnitTest")
+                        .matching { include("**/*.exec") },
+
+                    project.fileTree("$buildDir/outputs/code_coverage/${variant.name}AndroidTest")
+                        .matching { include("**/*.ec") }
+                    )
             }
 
-        jacocoTestReport.dependsOn(reportTask)
+
+        variant.artifacts.forScope(ScopedArtifacts.Scope.PROJECT)
+            .use(reportTask)
+            .toGet(
+                ScopedArtifact.CLASSES,
+                { _ -> allJars },
+                { _ -> allDirectories },
+            )
     }
 
     tasks.withType<Test>().configureEach {
         configure<JacocoTaskExtension> {
             // Required for JaCoCo + Robolectric
             // https://github.com/robolectric/robolectric/issues/2230
-            // TODO: Consider removing if not we don't add Robolectric
             isIncludeNoLocationClasses = true
 
             // Required for JDK 11 with the above

gradle.properties

@@ -39,3 +39,6 @@ kotlin.code.style=official
 # https://developer.android.com/build/releases/gradle-plugin#default-changes
 android.defaults.buildfeatures.resvalues=false
 android.defaults.buildfeatures.shaders=false
+
+# Run Roborazzi screenshot tests with the local tests
+roborazzi.test.verify=true