Add Android unit tests to plugin template (#120720)

* Add Java tests

* Add Kotlin

* Add integration testing

* Add cerate tests

dev/devicelab/lib/tasks/plugin_tests.dart

@@ -252,36 +252,50 @@ public class $pluginClass: NSObject, FlutterPlugin {
     // build files.
     await build(buildTarget, validateNativeBuildProject: false);
 
-    if (buildTarget == 'ios') {
-      await testWithNewIOSSimulator('TestNativeUnitTests', (String deviceId) async {
+    switch(buildTarget) {
+      case 'apk':
+        if (await exec(
+          path.join('.', 'gradlew'),
+          <String>['testDebugUnitTest'],
+          workingDirectory: path.join(rootPath, 'android'),
+          canFail: true,
+        ) != 0) {
+          throw TaskResult.failure('Platform unit tests failed');
+        }
+        break;
+      case 'ios':
+        await testWithNewIOSSimulator('TestNativeUnitTests', (String deviceId) async {
+          if (!await runXcodeTests(
+            platformDirectory: path.join(rootPath, 'ios'),
+            destination: 'id=$deviceId',
+            configuration: 'Debug',
+            testName: 'native_plugin_unit_tests_ios',
+            skipCodesign: true,
+          )) {
+            throw TaskResult.failure('Platform unit tests failed');
+          }
+        });
+        break;
+      case 'macos':
         if (!await runXcodeTests(
-          platformDirectory: path.join(rootPath, 'ios'),
-          destination: 'id=$deviceId',
+          platformDirectory: path.join(rootPath, 'macos'),
+          destination: 'platform=macOS',
           configuration: 'Debug',
-          testName: 'native_plugin_unit_tests_ios',
+          testName: 'native_plugin_unit_tests_macos',
           skipCodesign: true,
         )) {
           throw TaskResult.failure('Platform unit tests failed');
         }
-      });
-    } else if (buildTarget == 'macos') {
-      if (!await runXcodeTests(
-        platformDirectory: path.join(rootPath, 'macos'),
-        destination: 'platform=macOS',
-        configuration: 'Debug',
-        testName: 'native_plugin_unit_tests_macos',
-        skipCodesign: true,
-      )) {
-        throw TaskResult.failure('Platform unit tests failed');
-      }
-    } else if (buildTarget == 'windows') {
-      if (await exec(
-        path.join(rootPath, 'build', 'windows', 'plugins', 'plugintest', 'Release', 'plugintest_plugin_test'),
-        <String>[],
-        canFail: true,
-      ) != 0) {
-        throw TaskResult.failure('Platform unit tests failed');
-      }
+        break;
+      case 'windows':
+        if (await exec(
+          path.join(rootPath, 'build', 'windows', 'plugins', 'plugintest', 'Release', 'plugintest_plugin_test'),
+          <String>[],
+          canFail: true,
+        ) != 0) {
+          throw TaskResult.failure('Platform unit tests failed');
+        }
+        break;
     }
   }
 

packages/flutter_tools/templates/plugin/android-java.tmpl/build.gradle.tmpl

@@ -32,4 +32,19 @@ android {
     defaultConfig {
         minSdkVersion {{minSdkVersion}}
     }
+
+    dependencies {
+        testImplementation 'junit:junit:4.13.2'
+        testImplementation 'org.mockito:mockito-core:5.0.0'
+    }
+
+    testOptions {
+        unitTests.all {
+            testLogging {
+               events "passed", "skipped", "failed", "standardOut", "standardError"
+               outputs.upToDateWhen {false}
+               showStandardStreams = true
+            }
+        }
+    }
 }

packages/flutter_tools/templates/plugin/android-java.tmpl/src/test/java/androidIdentifier/pluginClassTest.java.tmpl

+package {{androidIdentifier}};
+
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+
+import io.flutter.plugin.common.MethodCall;
+import io.flutter.plugin.common.MethodChannel;
+import org.junit.Test;
+
+/**
+ * This demonstrates a simple unit test of the Java portion of this plugin's implementation.
+ *
+ * Once you have built the plugin's example app, you can run these tests from the command
+ * line by running `./gradlew testDebugUnitTest` in the `example/android/` directory, or
+ * you can run them directly from IDEs that support JUnit such as Android Studio.
+ */
+
+public class {{pluginClass}}Test {
+  @Test
+  public void onMethodCall_getPlatformVersion_returnsExpectedValue() {
+    {{pluginClass}} plugin = new {{pluginClass}}();
+
+    final MethodCall call = new MethodCall("getPlatformVersion", null);
+    MethodChannel.Result mockResult = mock(MethodChannel.Result.class);
+    plugin.onMethodCall(call, mockResult);
+
+    verify(mockResult).success("Android " + android.os.Build.VERSION.RELEASE);
+  }
+}

packages/flutter_tools/templates/plugin/android-kotlin.tmpl/build.gradle.tmpl

@@ -38,9 +38,27 @@ android {
 
     sourceSets {
         main.java.srcDirs += 'src/main/kotlin'
+        test.java.srcDirs += 'src/test/kotlin'
     }
 
     defaultConfig {
         minSdkVersion {{minSdkVersion}}
     }
+
+    dependencies {
+        testImplementation 'org.jetbrains.kotlin:kotlin-test'
+        testImplementation 'org.mockito:mockito-core:5.0.0'
+    }
+
+    testOptions {
+        unitTests.all {
+            useJUnitPlatform()
+
+            testLogging {
+               events "passed", "skipped", "failed", "standardOut", "standardError"
+               outputs.upToDateWhen {false}
+               showStandardStreams = true
+            }
+        }
+    }
 }

packages/flutter_tools/templates/plugin/android-kotlin.tmpl/src/test/kotlin/androidIdentifier/pluginClassTest.kt.tmpl

+package {{androidIdentifier}}
+
+import io.flutter.plugin.common.MethodCall
+import io.flutter.plugin.common.MethodChannel
+import kotlin.test.Test
+import org.mockito.Mockito
+
+/*
+ * This demonstrates a simple unit test of the Kotlin portion of this plugin's implementation.
+ *
+ * Once you have built the plugin's example app, you can run these tests from the command
+ * line by running `./gradlew testDebugUnitTest` in the `example/android/` directory, or
+ * you can run them directly from IDEs that support JUnit such as Android Studio.
+ */
+
+internal class {{pluginClass}}Test {
+  @Test
+  fun onMethodCall_getPlatformVersion_returnsExpectedValue() {
+    val plugin = {{pluginClass}}()
+
+    val call = MethodCall("getPlatformVersion", null)
+    val mockResult: MethodChannel.Result = Mockito.mock(MethodChannel.Result::class.java)
+    plugin.onMethodCall(call, mockResult)
+
+    Mockito.verify(mockResult).success("Android " + android.os.Build.VERSION.RELEASE)
+  }
+}

packages/flutter_tools/templates/template_manifest.json

@@ -251,9 +251,11 @@
         "templates/plugin/android-java.tmpl/build.gradle.tmpl",
         "templates/plugin/android-java.tmpl/projectName_android.iml.tmpl",
         "templates/plugin/android-java.tmpl/src/main/java/androidIdentifier/pluginClass.java.tmpl",
+        "templates/plugin/android-java.tmpl/src/test/java/androidIdentifier/pluginClassTest.java.tmpl",
         "templates/plugin/android-kotlin.tmpl/build.gradle.tmpl",
         "templates/plugin/android-kotlin.tmpl/projectName_android.iml.tmpl",
         "templates/plugin/android-kotlin.tmpl/src/main/kotlin/androidIdentifier/pluginClass.kt.tmpl",
+        "templates/plugin/android-kotlin.tmpl/src/test/kotlin/androidIdentifier/pluginClassTest.kt.tmpl",
         "templates/plugin/android.tmpl/.gitignore",
         "templates/plugin/android.tmpl/gradle/wrapper/gradle-wrapper.properties",
         "templates/plugin/android.tmpl/gradle.properties.tmpl",

packages/flutter_tools/test/commands.shard/permeable/create_test.dart

@@ -2452,6 +2452,63 @@ void main() {
     Logger: () => logger,
   });
 
+  testUsingContext('plugin includes native Kotlin unit tests', () async {
+    Cache.flutterRoot = '../..';
+
+    final CreateCommand command = CreateCommand();
+    final CommandRunner<void> runner = createTestCommandRunner(command);
+
+    await runner.run(<String>[
+      'create',
+      '--no-pub',
+      '--template=plugin',
+      '--org=com.example',
+      '--platforms=android',
+      projectDir.path]);
+
+    expect(projectDir
+        .childDirectory('android')
+        .childDirectory('src')
+        .childDirectory('test')
+        .childDirectory('kotlin')
+        .childDirectory('com')
+        .childDirectory('example')
+        .childDirectory('flutter_project')
+        .childFile('FlutterProjectPluginTest.kt'), exists);
+  }, overrides: <Type, Generator>{
+    FeatureFlags: () => TestFeatureFlags(),
+    Logger: () => logger,
+  });
+
+  testUsingContext('plugin includes native Java unit tests', () async {
+    Cache.flutterRoot = '../..';
+
+    final CreateCommand command = CreateCommand();
+    final CommandRunner<void> runner = createTestCommandRunner(command);
+
+    await runner.run(<String>[
+      'create',
+      '--no-pub',
+      '--template=plugin',
+      '--org=com.example',
+      '--platforms=android',
+      '-a', 'java',
+      projectDir.path]);
+
+    expect(projectDir
+        .childDirectory('android')
+        .childDirectory('src')
+        .childDirectory('test')
+        .childDirectory('java')
+        .childDirectory('com')
+        .childDirectory('example')
+        .childDirectory('flutter_project')
+        .childFile('FlutterProjectPluginTest.java'), exists);
+  }, overrides: <Type, Generator>{
+    FeatureFlags: () => TestFeatureFlags(),
+    Logger: () => logger,
+  });
+
   testUsingContext('plugin includes native Objective-C unit tests', () async {
     Cache.flutterRoot = '../..';