This section of the Flutter repository contains the command line developer tools for building Flutter applications.
Be sure to follow the instructions on CONTRIBUTING.md to set up your development environment. Further, familiarize yourself with the style guide, which we follow.
First, ensure that the Dart SDK and other necessary artifacts are available by invoking the Flutter Tools wrapper script. In this directory run:
$ flutter --version
To run Flutter Tools from source, in this directory run:
$ dart bin/flutter_tools.dart
followed by command-line arguments, as usual.
To run the analyzer on Flutter Tools, in this directory run:
$ flutter analyze
As with other parts of the Flutter repository, all changes in
behavior must
be tested. Tests live under the test/
subdirectory.
Hermetic unit tests of tool internals go under
test/general.shard
and must run in significantly less than
two seconds.
Tests of tool commands go under test/commands.shard
.
Hermetic tests go under its hermetic/
subdirectory.
Non-hermetic tests go under its permeable
sub-directory.
Avoid adding tests here and prefer writing either a unit test or a full
integration test.
Integration tests (e.g. tests that run the tool in a subprocess)
go under test/integration.shard
.
Slow web-related tests go in the test/web.shard
directory.
In general, the tests for the code in a file called
file.dart
should go in a file called
file_test.dart
in the subdirectory that matches the
behavior of the test.
The dart_test.yaml
file configures the timeout for these
tests to be 15 minutes. The test.dart
script that is used
in CI overrides this to two seconds for the
test/general.shard
directory, to catch behaviour that is
unexpectedly slow.
Please avoid setting any other timeouts.
The integration tests can be configured to use a specific local
engine variant by setting the FLUTTER_LOCAL_ENGINE
environment variable to the name of the local engine (e.g.
"android_debug_unopt"). If the local engine build requires a source
path, this can be provided by setting the
FLUTTER_LOCAL_ENGINE_SRC_PATH
environment variable. This
second variable is not necessary if the flutter
and
engine
checkouts are in adjacent directories.
export FLUTTER_LOCAL_ENGINE=android_debug_unopt
flutter test test/integration.shard/some_test_case
To run all of the unit tests:
$ flutter test test/general.shard
The tests in test/integration.shard
are slower to run
than the tests in test/general.shard
. Depending on your
development computer, you might want to limit concurrency. Generally it
is easier to run these on CI, or to manually verify the behavior you are
changing instead of running the test.
The integration tests also require the FLUTTER_ROOT
environment variable to be set. The full invocation to run everything
might therefore look something like:
$ export FLUTTER_ROOT=~/path/to/flutter-sdk
$ flutter test --concurrency 1
This may take some time (on the order of an hour). The unit tests alone take much less time (on the order of a minute).
You can run the tests in a specific file, e.g.:
$ flutter test test/general.shard/utils_test.dart
To force the Flutter Tools snapshot to be regenerated, delete the following files:
$ rm ../../bin/cache/flutter_tools.stamp ../../bin/cache/flutter_tools.snapshot