[tools] Add build_test_fast.py for a faster edit-compile-test loop This change introduces `tools/build_test_fast.py`, a developer-focused wrapper script that automatically infers and builds the *minimal* required GN targets needed to run a specific test, avoiding the expensive overhead of building the full SDK (e.g. `create_sdk`) during local iteration. Features: - Infers the correct `test.py` compiler (`-c`) from the provided test paths (e.g., `tests/web/wasm` -> `dart2wasm`). - Infers the correct minimal GN targets for the selected compiler. For example, DDC tests now only build `ddc_stable_test_local` and `create_common_sdk`, taking ~4 seconds instead of 5 minutes. - Automatically defaults web compilers (`dart2js`, `dart2wasm`, `ddc`) to use the `d8` runtime to prevent noisy browser popups during testing, unless explicitly overridden. - Synchronizes the default `mode` between `build.py` (debug) and `test.py` (release) to prevent silent snapshot resolution failures. - Prints clear, copy-pasteable execution commands for both the build and test phases. - Displays a prominent warning if a test fails, reminding the developer to verify the minimal target mapping against `tools/bots/test_matrix.json`. - Adds documentation for the script to `docs/Testing.md`. Change-Id: I75473cdacca13f78dd271d9a31d5dcb15df57f6f Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/499043 Commit-Queue: Kevin Moore <kevmoo@google.com> Reviewed-by: Jake Macdonald <jakemac@google.com> https://dart.googlesource.com/sdk/+/a5d8c88952983e7d67b417ae237abc0d46d1d379
Monorepo is:
With depot_tools installed and on your path, create a directory for your monorepo checkout and run these commands to create a gclient solution in that directory:
mkdir monorepo cd monorepo gclient config --unmanaged https://dart.googlesource.com/monorepo gclient sync -D
This gives you a checkout in the monorepo directory that contains:
monorepo/ DEPS - the DEPS used for this gclient checkout commits.json - the pinned commits for Dart, flutter/engine, and flutter/flutter tools/ - scripts used to create monorepo DEPS engine/src/ - the flutter/buildroot repo flutter/ - the flutter/engine repo out/ - the build directory, where Flutter engine builds are created third_party/ - Flutter dependencies checked out by DEPS dart/ - the Dart SDK checkout. third_party - Dart dependencies, also used by Flutter flutter/ - the flutter/flutter repo
Flutter's instructions for building the engine are at Compiling the engine
They can be followed closely, with a few changes:
goma_ctl ensure_start is sufficient.Example build commands that work on linux:
MONOREPO_PATH=$PWD if [[ ! $PATH =~ (^|:)$MONOREPO_PATH/flutter/bin(:|$) ]]; then PATH=$MONOREPO_PATH/flutter/bin:$PATH fi export GOMA_DIR=$(dirname $(command -v gclient))/.cipd_bin goma_ctl ensure_start pushd engine/src flutter/tools/gn --goma --no-prebuilt-dart-sdk --unoptimized --full-dart-sdk autoninja -C out/host_debug_unopt popd
The Flutter commands used to build and run apps will use the locally built Flutter engine and Dart SDK, instead of the one downloaded by the Flutter tool, if the --local-engine option is provided.
For example, to build and run the Flutter spinning square sample on the web platform,
MONOREPO_PATH=$PWD cd flutter/examples/layers flutter --local-engine=host_debug_unopt \ -d chrome run widgets/spinning_square.dart cd $MONOREPO_PATH
To build for desktop, specify the desktop platform device in flutter run as -d macos or -d linux or -d windows. You may also need to run the command
flutter create --platforms=windows,macos,linux
on existing apps, such as sample apps. New apps created with flutter create already include these support files. Details of desktop support are at Desktop Support for Flutter
Tests in the Flutter source tree can be run with the flutter test command, run in the directory of a package containing tests. For example:
MONOREPO_PATH=$PWD cd flutter/packages/flutter flutter test --local-engine=host_debug_unopt cd $MONOREPO_PATH
Please file an issue or email the dart-engprod team with any problems with or questions about using monorepo.
We will update this documentation to address them.
flutter commands may download the engine and Dart SDK files for the configured channel, even though they will be using the local engine and its SDK.gclient sync needs to be run in an administrator session, because some installed dependencies create symlinks.