| commit | f08de9429e05b365fbd95d68d0a5659e7677c74a | [log] [tgz] |
|---|---|---|
| author | Ben Konyi <bkonyi@google.com> | Wed Jun 11 13:57:15 2025 -0400 |
| committer | dart-internal-monorepo <dart-internal-monorepo@dart-ci-internal.iam.gserviceaccount.com> | Wed Jun 11 11:42:44 2025 -0700 |
| tree | 0c355a47d69a0015fbd7088f407acaa9f8b3ee5e | |
| parent | b15ee5790be4e6cea58ed7d3ecf8fc9837100f65 [diff] |
[ Widget Preview ] Don't try to load previews with compile-time errors (#170262) This change reworks how preview detection is performed to allow for identifying libraries which contain compile-time errors or transitive dependencies with compile-time errors. Previously, introducing a compile-time error into a preview containing library's dependency chain would result in the preview environment no longer being updated due to a failed compilation during hot reload. Users would first need to know to fix the compilation error before being able to make updates to previews. With this change, the preview detector builds and maintains a dependency graph, propagating errors from libraries to their upstream dependencies. If a file containing a preview would fail to compile, it is no longer inserted into the widget preview environment. In its place, an error message is displayed informing the user that there's a compilation error in a library that needs to be fixed first. This change needs some follow up work to create a proper UI for displaying the compilation error messaging, batch processing of bulk file system operations (e.g., directory deletion) to avoid performance issues, and some refactoring. Work towards #166430 https://dart.googlesource.com/external/github.com/flutter/flutter/+/b9a99683aee89e31fa55a8a41c9ade9093d2df2a
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.