New Android version

Support a new android API level flutter go/flutter-android-new-api-level

Objective

Provide a list of areas to consider and examples of former work for how to update flutter to support a new version of the android API. This happens every fall and flutter developers expect to build against the latest versions quickly after they are available.

Overview

New Android features

New android features can require a broad spectrum of work. Some will require nothing from flutter. Some will require a lot of work, such as the support for “back preview”. The android team generally needs to be aware and schedule work ahead of time.

Update Gradle/AGP support

Sometimes newer versions of gradle are required to build without warning against a new version of android api. The warning looks like

WARNING:We recommend using a newer Android Gradle plugin to use compileSdkPreview = "somenamedversion"
This Android Gradle plugin (X.X.X) was tested up to compileSdk = XX

Bump the gradle version used in the engine.

Update Robolectric

Robolectric is a dependency that allows us to write unit tests that run on a local development machine against the android api surface without being on an android device. Update what version of Robolectric we use in framework, engine and packages. Example packages: https://github.com/flutter/packages/pull/4018 Example engine: https://github.com/flutter/engine/pull/42965

Update CI

Update emulator and/or physical device testing to use the new android api version for framework, engine and packages. Firebase test lab emulators and physical devices need support from the firebase team Run command gcloud firebase test android models list documentation to see available devices. Flutter managed Emulators (engine) require a new AVD image to one that supports the new api: https://flutter-review.googlesource.com/c/recipes/+/45049 Example Framework: https://flutter-review.googlesource.com/c/recipes/+/45048 Example Engine: https://github.com/flutter/engine/pull/42492 Packages Modify https://github.com/flutter/packages/blob/main/.cirrus.yml “firebase_test_lab_script” Specifically the value for “--device” ./script/tool_runner.sh firebase-test-lab --device model=redfin,version=30 --exclude=script/configs/exclude_integration_android.yaml https://github.com/flutter/packages/pull/4430

Update documentation

Update documentation page to indicate the new api is tested https://docs.flutter.dev/reference/supported-platforms

Modify defaults

In flutter/flutter: Update default compile sdk version and target sdk version to the new api value Code here https://github.com/flutter/flutter/blob/master/packages/flutter_tools/gradle/src/main/groovy/flutter.groovy Follow comments in that file to update other locations that are assumed to be the same. Example bumping min sdk which is similar but different: https://github.com/flutter/flutter/pull/125515 In flutter/buildroot: Upload new android sdk version to CIPD (steps at end of document) Update default android sdk version https://github.com/flutter/buildroot/blob/7984a08044b94bfb4c466ac881c6b56fdfe9148b/build/config/android/config.gni#L19 In flutter/engine: Update android SDK in DEPS file https://github.com/flutter/engine/blob/9289cb6a36aa86990e3ffe0f20324dafa38e7c11/DEPS#L731 Update buildroot version in DEPS file to consume the changes in the flutter/buildroot steps above https://github.com/flutter/engine/blob/9289cb6a36aa86990e3ffe0f20324dafa38e7c11/DEPS#L260 In flutter/packages Set examples to build with the new api.

Test “Integration Test” package

Integration test is a package shipped in the flutter tool for running integration tests on flutter apps. Ensure that the integration test package has an example that targets the new api level on the most recent published stable version of the flutter tool.

Related documents

Emulators for Flutter Android Testing (PUBLICLY SHARED)

Additional notes

Upload new SDK version to CIPD and consume in buildroot

Make a fork of the buildroot if you haven’t yet. Get CIPD temporary write access, if you don’t have it: Make a github issue describing that there is a new android release that needs to be uploaded to CIPD Go to go/flutter-luci-cipd#requesting-writeread-access-to-cipd-packages and click request access on the hyperlinked page Fill out the justification with b/12345 - (the form requires a buganizer link, and the addition of b/12345 satisfies this). Reach out to someone on the infra team to get your request approved Run the create_cipd_packages.sh script with your desired version tag (note that there is a .ci.yaml validation step that requires this version tag to be a combination of lowercase letters and numbers). The script pulls the version that will be uploaded from the packages.txt file in the same subdirectory. The remaining steps are to consume the changes in the buildroot, and then consume those buildroot changes in the engine.