README.md 3.78 KB
Newer Older
1
# Flutter Tools
2

3 4
This section of the Flutter repository contains the command line developer tools
for building Flutter applications.
Devon Carew's avatar
Devon Carew committed
5

6
## Working on Flutter Tools
Luan Nico's avatar
Luan Nico committed
7

8
Be sure to follow the instructions on [CONTRIBUTING.md](../../CONTRIBUTING.md)
9 10 11
to set up your development environment. Further, familiarize yourself with the
[style guide](https://github.com/flutter/flutter/wiki/Style-guide-for-Flutter-repo),
which we follow.
Devon Carew's avatar
Devon Carew committed
12

13
### Setting up
14 15 16 17

First, ensure that the Dart SDK and other necessary artifacts are available by
invoking the Flutter Tools wrapper script. In this directory run:
```shell
18
$ flutter --version
19 20
```

21
### Running the Tool
22 23 24

To run Flutter Tools from source, in this directory run:
```shell
25
$ dart bin/flutter_tools.dart
26
```
27
followed by command-line arguments, as usual.
28

29

30
### Running the analyzer
31 32 33

To run the analyzer on Flutter Tools, in this directory run:
```shell
34
$ flutter analyze
35 36
```

37 38 39 40 41
### Writing tests

As with other parts of the Flutter repository, all changes in behavior [must be
tested](https://github.com/flutter/flutter/wiki/Style-guide-for-Flutter-repo#write-test-find-bug).
Tests live under the `test/` subdirectory.
42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65

- 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.
66

67 68 69 70 71 72 73 74 75 76 77
#### Using local engine builds in integration tests

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.

```shell
export FLUTTER_LOCAL_ENGINE=android_debug_unopt
78
flutter test test/integration.shard/some_test_case
79 80
```

81
### Running the tests
82

83
To run all of the unit tests:
84

85
```shell
86
$ flutter test test/general.shard
87 88
```

89 90 91 92 93
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.
94

95 96 97
The integration tests also require the `FLUTTER_ROOT` environment
variable to be set. The full invocation to run everything might
therefore look something like:
98 99 100

```shell
$ FLUTTER_ROOT=~/path/to/flutter-sdk
101
$ flutter test --concurrency 1
102 103
```

104 105
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).
106

107
You can run the tests in a specific file, e.g.:
108 109

```shell
110
$ flutter test test/general.shard/utils_test.dart
111 112 113 114 115 116
```

### Forcing snapshot regeneration

To force the Flutter Tools snapshot to be regenerated, delete the following
files:
117
```shell
118
$ rm ../../bin/cache/flutter_tools.stamp ../../bin/cache/flutter_tools.snapshot
119
```