This folder contains e2e integration tests for the engine in conjunction with a fake dart:ui framework running in JIT or AOT.
It intentionally has no dependencies on the Flutter framework or tooling, such that it should be buildable as a presubmit or postsubmit to the engine even in the face of changes to Dart or dart:ui that require upstream changes in the Flutter tooling.
Create a new subclass of Scenario and add it to the map in scenarios.dart. For an example, see animated_color_square.dart, which draws a continuously animating colored square that bounces off the sides of the viewport.
Then set the scenario from the Android or iOS app by calling “set_scenario” on platform channel.
Build the ios_debug_sim_unopt engine variant, and run
./run_ios_tests.sh
in your shell.
To run or debug in Xcode, open the xcodeproj file located in <engine_out_dir>/ios_debug_sim_unopt/scenario_app/Scenarios/Scenarios.xcodeproj.
For PlatformView tests on iOS, you‘ll also have to edit the dictionaries in AppDelegate.m and GoldenTestManager.m so that the correct golden image can be found. Also, you’ll have to add a GoldenPlatformViewTests in PlatformViewUITests.m.
If PlatformViewRotation is failing, make sure Simulator app Device > Rotate Device Automatically is selected, or run:
defaults write com.apple.iphonesimulator RotateWindowWhenSignaledByGuest -int 1
Screenshots are saved as XCTAttachment‘s. If you look at the output from running the tests you’ll find a path in the form: /Users/$USER/Library/Developer/Xcode/DerivedData/Scenarios-$HASH. Inside that directory you'll find ./Build/Products/Debug-iphonesimulator/ScenariosUITests-Runner.app/PlugIns/ScenariosUITests.xctest/ which is where all the images that were compared against golden reside.
For emulators running on a x64 host, build android_debug_unopt_x64 using ./tools/gn --android --unoptimized --goma --android-cpu=x64.
Then, launch the emulator, and run ./testing/scenario_app/run_android_tests.sh android_debug_unopt_x64.
If you wish to build a different engine variant, make sure to pass that variant to the script run_android_tests.sh.
If you make a change to the source code, you would need to rebuild the same engine variant.
To run the smoke test on Firebase TestLab test, build android_profile_arm64, and run ./flutter/ci/firebase_testlab.py. If you wish to test a different variant, e.g. debug arm64, pass --variant android_debug_arm64.
If a Gradle dependency is updated, lockfiles must be regenerated.
To generate new lockfiles, run:
cd android/app ../../../../../third_party/gradle/bin/gradle generateLockfiles