A screenshot image with overlaid status bar placed in a device frame.
For introduction to Screenshots see https://medium.com/@nocnoc/automated-screenshots-for-flutter-f78be70cd5fd.
Screenshots is a standalone command line utility and package for capturing screenshot images for Flutter.
Screenshots will start the required android emulators and iOS simulators (or find attached devices), run your screen capture tests on each emulator/simulator (or device), process the images, and drop them off to Fastlane for delivery to both stores.
It is inspired by three tools from Fastlane:
This is used to capture screenshots on iOS using iOS UI Tests.
This captures screenshots on android using Android Espresso tests.
This is used to place captured iOS screenshots in a device frame.
Since all three of these Fastlane tools do not work with Flutter, Screenshots combines key features of these Fastlane tools into one tool.
Since Flutter integration testing is designed to work transparently across iOS and Android, capturing images using Screenshots is easy.
- Works with your existing tests
Add a single line for each screenshot.
- Run your tests on any device
Select the devices you want to run on, using a convenient config file. Screenshots will find the devices (real or emulated) and run your tests.
- One run for both platforms
Screenshots runs your tests on both iOS and Android in one run.
(as opposed to making separate Snapshots and Screengrab runs)
- One run for multiple locales
If your app supports multiple locales, Screenshots will optionally set the locales listed in the config file before running each test.
- One run for frames
Optionally places images in device frames in same run.
(as opposed to making separate FrameIt runs... which supports iOS only)
- One run for clean status bars
Every image that Screenshots generates has a clean status bar.
(no need to run a separate stage to clean-up status bars)
- Works with Fastlane
Screenshots drops-off images where Fastlane expects to find them. Fastlane's deliver and supply can then be used to upload to respective stores.
- Works with FrameIt
Works with Fastlane's FrameIt text and background feature to add text, etc... to a framed screenshot generated by
- Works with any attached real devices
Use any number of real devices to capture screenshots.
Additional automation features:
- Screenshots runs in the cloud.
For live demo of Screenshots running with the internationalized example app on macOS in cloud, see below
- Screenshots works with any CI/CD tool.
For live demo of uploading images, generated by Screenshots, to both store consoles, see demo of Fledge at https://github.com/mmcc007/fledge#demo
$ brew update && brew install imagemagick $ pub global activate screenshots
pub is not found, add to PATH using:
export PATH="$PATH:<path to flutter installation directory>/bin/cache/dart-sdk/bin"
Or, if using a config file other than the default 'screenshots.yaml':
$ screenshots -c <path to config file>
$ screenshots -h usage: screenshots [-h] [-c <config file>] [-m <normal|recording|comparison|archive>] sample usage: screenshots -c, --config=<screenshots.yaml> Path to config file. (defaults to "screenshots.yaml") -m, --mode=<normal|recording|comparison|archive> If mode is recording, screenshots will be saved for later comparison. If mode is archive, screenshots will be archived and cannot be uploaded via fastlane. [normal (default), recording, comparison, archive] -h, --help Display this help information.
Modifying your tests for Screenshots
A special function is provided in the Screenshots package that is called by the test each time you want to capture a screenshot. Screenshots will then process the images appropriately during a Screenshots run.
To capture screenshots in your tests:
- Include the Screenshots package in your pubspec.yaml's dev_dependencies section
screenshots: ^<current version>
- In your tests
- Import the dependencies
- Create the config at start of test
final configInfo = Config().configInfo;
- Throughout the test make calls to capture screenshots
await screenshot(driver, configInfo, 'myscreenshot1');
- Import the dependencies
Note: make sure your screenshot names are unique across all your tests.
Note: to turn off the debug banner on your screens, in your integration test's main(), call:
WidgetsApp.debugAllowBannerOverride = false; // remove debug banner for screenshots
Modifying tests based on screenshots environment
In some cases it is useful to know what device, device type, screen size and locale you are currently testing with. To obtain this information in your test use:
final screenshotsEnv = config.screenshotsEnv;
See https://github.com/flutter/flutter/issues/31609 for related
flutter driver issue.
Screenshots uses a configuration file to configure a run.
The default config filename is
# A list of screen capture tests tests: - test_driver/main1.dart - test_driver/main2.dart # Note: flutter driver expects a pair of files for testing # For example: # main1.dart is the test app (that calls your app) # main1_test.dart is the matching test that flutter driver # expects to find. # Interim location of screenshots from tests staging: /tmp/screenshots # A list of locales supported by the app locales: - de-DE - en-US # A map of devices to emulate devices: ios: iPhone XS Max: frame: false iPad Pro (12.9-inch) (3rd generation): android: Nexus 6P: # Frame screenshots frame: true
Individual devices can be configured in
screenshots.yaml by specifying per device parameters.
|frame||true/false||optional||Controls whether screenshots generated on the device should be placed in a frame. Overrides the global frame setting (see example |
Note: images generated for those devices where framing is disabled are probably not suitable for upload, but can be used for local review.
Screenshots can be used to monitor any unexpected changes to the UI by comparing the new screenshots to previously recorded screenshots. Any differences will be highlighted in a 'diff' image for review.
To use this feature:
- Add the location of your recording directory to a
- Run a recording to capture your screenshots:
screenshots -m recording
- Run subsequent Screenshots with:
Screenshots will compare the new screenshots with the recorded screenshots and generate a 'diff' image for each screenshot that does not compare. The diff image highlights the differences in red.
screenshots -m comparison
To generate screenshots for local use, such as generating reports of changes to UI over time, etc... use 'archive' mode.
To enable this mode:
- Add the location of your archive directory to screenshots.yaml:
- Run Screenshots with:
$ screenshots -m archive
Integration with Fastlane
Since Screenshots is intended to be used with Fastlane, after Screenshots completes, the images can be found in your project at:
Tip: One way to use Screenshots with Fastlane is to call Screenshots before calling Fastlane (or optionally call from Fastlane). Fastlane (for either iOS or Android) will then find the images in the appropriate place.
(For a live demo of using Fastlane to upload screenshot images to both store consoles, see demo of Fledge at https://github.com/mmcc007/fledge#demo)
iOS images generated by Screenshots can also be further processed using FrameIt's text and background feature.
To change the devices to run your tests on, just change the list of devices in screenshots.yaml.
Make sure each device you select has a supported screen and a
corresponding attached device or installed emulator/simulator. To bypass
the supported screen requirement use
frame: false for each related device in your
For each selected device:
- Confirm device is present in screens.yaml.
- Add device to the list of devices in screenshots.yaml.
- Confirm a real device is attached, or install an emulator/simulator for device.
Screenshots will check your configuration before running for any errors and provide a guide on how to resolve.
To upgrade, simply re-issue the install command
$ pub global activate screenshots
Note: the Screenshots version should be the same for both the command line and in your
- If upgrading the command line version of Screenshots, also upgrade the version of Screenshots in your pubspec.yaml.
- If upgrading the version of Screenshots in your pubspec.yaml, also upgrade the command line version.
To check the version of Screenshots currently installed:
pub global list
Sample run on Travis
To view the images generated by Screenshots during run on travis see:
- Running Screenshots in the cloud is useful for automating the generation of your screenshots in a CI/CD environment.
- Running Screenshots on macOS in the cloud can be used to generate your screenshots when developing on Linux and/or Windows (if not using locally attached iOS devices).
Issues and Pull Requests
Your feedback is welcome and is used to guide where development effort is focused. So feel free to create as many issues and pull requests as you want. You should expect a timely and considered response.