espresso 0.0.1

Java classes for testing Flutter apps using Espresso.

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:

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:

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.

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:

./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>