| # Scenario App |
| |
| [](https://github.com/flutter/flutter/issues?q=is%3Aopen+is%3Aissue+label%3A%22e%3A+scenario-app%22) |
| |
| This package simulates a Flutter app that uses the engine (`dart:ui`) only, |
| in conjunction with iOS-specific embedding code that simulates the use of the |
| engine in a real app (such as plugins and platform views). |
| |
| [`run_ios_tests.sh`](run_ios_tests.sh) is used to run the tests on a simulator. |
| |
| See also: |
| |
| - [File an issue][file_issue] with the `e: scenario-app` label. |
| - [`lib/`](lib/), the Dart code and instrumentation for the scenario app. |
| - [`ios/`](ios/), the iOS-side native code and tests. |
| |
| [file_issue]: https://github.com/flutter/flutter/issues/new?labels=e:%20scenario-app,engine,team-ios |
| |
| ## Adding a New Scenario |
| |
| Like a regular Flutter iOS app, the Scenario app consists of the [iOS embedding |
| code](ios/Scenarios/Scenarios/AppDelegate.m) and the dart logic that are |
| `Scenario`s. |
| |
| To introduce a new subclass of [Scenario](lib/src/scenario.dart), add it to the map |
| in [scenarios.dart](lib/src/scenarios.dart). For an example, |
| [animated_color_square.dart](lib/src/animated_color_square.dart), which draws a |
| continuously animating colored square that bounces off the sides of the |
| viewport. |
| |
| The Scenarios app loads a `Scenario` when it receives a `set_scenario` method call |
| on the `driver` platform channel from the objective-c code. However if you're |
| adding a UI test this is typically not needed as you typically should add a new |
| launch argument. See |
| [ScenariosUITests](ios/Scenarios/ScenariosUITests/README.md) for more details. |
| |
| ## Running a specific test |
| |
| The `run_ios_tests.sh` script runs all tests in the `Scenarios` project. If you're |
| debugging a specific test, rebuild the `ios_debug_sim_unopt_arm64` engine variant |
| (assuming testing on a simulator on Apple Silicon chips), and open |
| `src/out/ios_debug_sim_unopt_arm64/ios_scenario_app/Scenarios.xcworkspace` in xcode. |
| Use the xcode UI to run the test. |
