[espresso] Adds EspressoFlutter as a first-party plugin (#2369)

* Initial open source release of Espresso bindings for Flutter as a new first-party plugin, espresso.

packages/espresso/.gitignore

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+.DS_Store
+.dart_tool/
+
+.packages
+.pub/
+
+build/

packages/espresso/.metadata

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+# This file tracks properties of this Flutter project.
+# Used by Flutter tool to assess capabilities and perform upgrades etc.
+#
+# This file should be version controlled and should not be manually edited.
+
+version:
+  revision: 0190e40457d43e17bdfaf046dfa634cbc5bf28b9
+  channel: unknown
+
+project_type: plugin

packages/espresso/CHANGELOG.md

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+## 0.0.1
+
+* Initial open-source release of Espresso bindings for Flutter.

packages/espresso/LICENSE

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+// Copyright 2019 The Chromium Authors. All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//    * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//    * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//    * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

packages/espresso/README.md

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+# espresso
+
+Provides bindings for Espresso tests of Flutter Android apps.
+
+## Installation
+
+Add the `espresso` package as a `dev_dependency` in your app's pubspec.yaml. If you're testing the example app of a package, add it as a dev_dependency of the main package as well.
+
+Add ```android:usesCleartextTraffic="true"``` in the ```<application>``` in the AndroidManifest.xml
+of the Android app used for testing. It's best to put this in a debug or androidTest
+AndroidManifest.xml so that you don't ship it to end users. (See the example app of this package.)
+
+Add dependencies to your build.gradle:
+
+```groovy
+dependencies {
+    testImplementation 'junit:junit:4.12'
+    testImplementation "com.google.truth:truth:1.0"
+    androidTestImplementation 'androidx.test:runner:1.1.1'
+    androidTestImplementation 'androidx.test.espresso:espresso-core:3.1.1'
+
+    // Core library
+    api 'androidx.test:core:1.2.0'
+
+    // AndroidJUnitRunner and JUnit Rules
+    androidTestImplementation 'androidx.test:runner:1.1.0'
+    androidTestImplementation 'androidx.test:rules:1.1.0'
+
+    // Assertions
+    androidTestImplementation 'androidx.test.ext:junit:1.0.0'
+    androidTestImplementation 'androidx.test.ext:truth:1.0.0'
+    androidTestImplementation 'com.google.truth:truth:0.42'
+
+    // Espresso dependencies
+    androidTestImplementation 'androidx.test.espresso:espresso-core:3.1.0'
+    androidTestImplementation 'androidx.test.espresso:espresso-contrib:3.1.0'
+    androidTestImplementation 'androidx.test.espresso:espresso-intents:3.1.0'
+    androidTestImplementation 'androidx.test.espresso:espresso-accessibility:3.1.0'
+    androidTestImplementation 'androidx.test.espresso:espresso-web:3.1.0'
+    androidTestImplementation 'androidx.test.espresso.idling:idling-concurrent:3.1.0'
+
+    // The following Espresso dependency can be either "implementation"
+    // or "androidTestImplementation", depending on whether you want the
+    // dependency to appear on your APK's compile classpath or the test APK
+    // classpath.
+    androidTestImplementation 'androidx.test.espresso:espresso-idling-resource:3.1.0'
+}
+```
+
+Create an `android/app/src/androidTest` folder and put a test file in a package-appropriate subfolder, e.g. `android/app/src/androidTest/java/com/example/MainActivityTest.java`:
+
+```java
+package com.example.espresso_example;
+
+import static androidx.test.espresso.flutter.EspressoFlutter.onFlutterWidget;
+import static androidx.test.espresso.flutter.action.FlutterActions.click;
+import static androidx.test.espresso.flutter.action.FlutterActions.syntheticClick;
+import static androidx.test.espresso.flutter.assertion.FlutterAssertions.matches;
+import static androidx.test.espresso.flutter.matcher.FlutterMatchers.isDescendantOf;
+import static androidx.test.espresso.flutter.matcher.FlutterMatchers.withText;
+import static androidx.test.espresso.flutter.matcher.FlutterMatchers.withTooltip;
+import static androidx.test.espresso.flutter.matcher.FlutterMatchers.withType;
+import static androidx.test.espresso.flutter.matcher.FlutterMatchers.withValueKey;
+import static com.google.common.truth.Truth.assertThat;
+import static org.junit.Assert.fail;
+
+import androidx.test.core.app.ActivityScenario;
+import androidx.test.espresso.flutter.EspressoFlutter.WidgetInteraction;
+import androidx.test.espresso.flutter.assertion.FlutterAssertions;
+import androidx.test.espresso.flutter.matcher.FlutterMatchers;
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+/** Unit tests for {@link EspressoFlutter}. */
+@RunWith(AndroidJUnit4.class)
+public class MainActivityTest {
+
+    @Before
+    public void setUp() throws Exception {
+        ActivityScenario.launch(MainActivity.class);
+    }
+
+    @Test
+    public void performClick() {
+        onFlutterWidget(withTooltip("Increment")).perform(click());
+        onFlutterWidget(withValueKey("CountText")).check(matches(withText("Button tapped 1 time.")));
+    }
+ ```
+
+You'll need to create a test app that enables the Flutter driver extension.
+You can put this in your test_driver/ folder, e.g. test_driver/example.dart.
+
+```dart
+import 'package:flutter_driver/driver_extension.dart';
+import '../lib/main.dart' as app;
+
+void main() {
+  enableFlutterDriverExtension();
+  app.main();
+}
+```
+
+The following command line command runs the test locally:
+
+```
+./gradlew app:connectedAndroidTest -Ptarget=`pwd`/../test_driver/example.dart
+```
+
+Espresso tests can also be run on [Firebase Test Lab](https://firebase.google.com/docs/test-lab):
+
+```
+./gradlew app:assembleAndroidTest
+./gradlew app:assembleDebug -Ptarget=<path_to_test>.dart
+gcloud auth activate-service-account --key-file=<PATH_TO_KEY_FILE>
+gcloud --quiet config set project <PROJECT_NAME>
+gcloud firebase test android run --type instrumentation \
+  --app build/app/outputs/apk/debug/app-debug.apk \
+  --test build/app/outputs/apk/androidTest/debug/app-debug-androidTest.apk\
+  --timeout 2m \
+  --results-bucket=<RESULTS_BUCKET> \
+  --results-dir=<RESULTS_DIRECTORY>
+```
+

packages/espresso/android/.gitignore

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+*.iml
+.gradle
+/local.properties
+/.idea/workspace.xml
+/.idea/libraries
+.DS_Store
+/build
+/captures

packages/espresso/android/build.gradle

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+group 'com.example.espresso'
+version '1.0'
+
+buildscript {
+    repositories {
+        google()
+        jcenter()
+    }
+
+    dependencies {
+        classpath 'com.android.tools.build:gradle:3.5.0'
+    }
+}
+
+rootProject.allprojects {
+    repositories {
+        google()
+        jcenter()
+    }
+}
+
+apply plugin: 'com.android.library'
+
+android {
+    compileSdkVersion 28
+
+    defaultConfig {
+        minSdkVersion 16
+        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
+    }
+    lintOptions {
+        disable 'InvalidPackage'
+    }
+}
+
+dependencies {
+    implementation 'com.google.guava:guava:28.1-android'
+    implementation 'com.squareup.okhttp3:okhttp:3.12.1'
+    implementation 'com.google.code.gson:gson:2.8.6'
+    androidTestImplementation 'org.hamcrest:hamcrest:2.2'
+
+    testImplementation 'junit:junit:4.12'
+    testImplementation "com.google.truth:truth:1.0"
+    api 'androidx.test:runner:1.1.1'
+    api 'androidx.test.espresso:espresso-core:3.1.1'
+
+    // Core library
+    api 'androidx.test:core:1.0.0'
+
+    // AndroidJUnitRunner and JUnit Rules
+    api 'androidx.test:runner:1.1.0'
+    api 'androidx.test:rules:1.1.0'
+
+    // Assertions
+    api 'androidx.test.ext:junit:1.0.0'
+    api 'androidx.test.ext:truth:1.0.0'
+    api 'com.google.truth:truth:0.42'
+
+    // Espresso dependencies
+    api 'androidx.test.espresso:espresso-core:3.1.0'
+    api 'androidx.test.espresso:espresso-contrib:3.1.0'
+    api 'androidx.test.espresso:espresso-intents:3.1.0'
+    api 'androidx.test.espresso:espresso-accessibility:3.1.0'
+    api 'androidx.test.espresso:espresso-web:3.1.0'
+    api 'androidx.test.espresso.idling:idling-concurrent:3.1.0'
+
+    // The following Espresso dependency can be either "implementation"
+    // or "androidTestImplementation", depending on whether you want the
+    // dependency to appear on your APK's compile classpath or the test APK
+    // classpath.
+    api 'androidx.test.espresso:espresso-idling-resource:3.1.0'
+}
+
+

packages/espresso/android/gradle.properties

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+org.gradle.jvmargs=-Xmx1536M
+android.enableR8=true
+android.useAndroidX=true
+android.enableJetifier=true

packages/espresso/android/gradle/wrapper/gradle-wrapper.properties

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+#Tue Nov 26 13:04:21 PST 2019
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-5.4.1-all.zip

packages/espresso/android/settings.gradle

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+rootProject.name = 'espresso'

packages/espresso/android/src/main/AndroidManifest.xml

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+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+  package="com.example.espresso">
+</manifest>