a7f430a5ef
Summary: This PR adds support for using Yoga Swift dependents when Yoga is pulled as a static library. Currently swift projects trying to pull static libraries are unable to import the module. The reason for that is because the `DEFINES_MODULES` build setting is set to`NO`. If a Swift Framework is trying to `pod spec lint --use-libraries` with `Yoga` as a dependency, the validation will fail. With the `DEFINES_MODULE` enabled, the product will be treated as defining its own module. This enables automatic production of LLVM module map files when appropriate, and allows the product to be imported as a module. A workaround to this issue would be passing the `:modular_headers` flag to the `Podfile`, but that would not fix the `pod spec lint` validation for framework/library dependencies, it would just allow consuming applications to build and run. An example of this issue would be [SonarKit](https://github.com/facebook/Sonar/blob/master/iOS/SonarKit.podspec). `SonarKit` wasn't able to validate its podspec due to `YogaKit` (Swift Framework) depending on `Yoga` and SonarKit validating with the `--use-libraries` flag due to the c++ dependencies. We had to create a new version of [Yoga 1.9 podspec](https://github.com/facebook/Sonar/blob/master/Specs/Yoga/1.9/Yoga.podspec.json) and make sure to set the `DEFINES_MODULE` flag of the pod target. After that, we were able to `pod spec lint` `SonarKit.podspec` successfully. After merging a new `tag` should be created and the new podspec should be pushed to cocoapods master repository. Pull Request resolved: https://github.com/facebook/yoga/pull/793 Reviewed By: passy Differential Revision: D8820126 Pulled By: priteshrnandgaonkar fbshipit-source-id: 98eae3c31ec67a03c0fe97e05ab9e79446fa9f78
Yoga 
Building
Yoga builds with buck. Make sure you install buck before contributing to Yoga. Yoga's main implementation is in C, with bindings to supported languages and frameworks. When making changes to Yoga please ensure the changes are also propagated to these bindings when applicable.
Testing
For testing we rely on gtest as a submodule. After cloning Yoga run git submodule init followed by git submodule update.
For any changes you make you should ensure that all the tests are passing. In case you make any fixes or additions to the library please also add tests for that change to ensure we don't break anything in the future. Tests are located in the tests directory. Run the tests by executing buck test //:yoga.
Instead of manually writing a test which ensures parity with web implementations of Flexbox you can run gentest/gentest.rb to generated a test for you. You can write html which you want to verify in Yoga, in gentest/fixtures folder, such as the following.
<div id="my_test" style="width: 100px; height: 100px; align-items: center;">
<div style="width: 50px; height: 50px;"></div>
</div>
Run gentest/gentest.rb to generate test code and re-run buck test //:yoga to validate the behavior. One test case will be generated for every root div in the input html.
You may need to install the latest watir-webdriver gem (gem install watir-webdriver) and ChromeDriver to run gentest/gentest.rb Ruby script.
.NET
.NET testing is not integrated in buck yet, you might need to set up .NET testing environment. We have a script which to launch C# test on macOS, csharp/tests/Facebook.Yoga/test_macos.sh.
Benchmarks
Benchmarks are located in benchmark/YGBenchmark.c and can be run with buck run //benchmark:benchmark. If you think your change has affected performance please run this before and after your change to validate that nothing has regressed. Benchmarks are run on every commit in CI.
JavaScript
Installing through NPM
npm install yoga-layout
By default this will install the library and try to build for all platforms (node, browser asm, and standalone webpack). You may receive errors if you do not have the required platform development tools already installed. To preset the platform you'd like to build for you can set a .npmrc property first.
npm config set yoga-layout:platform standalone
This will now only run the standalone webpack build upon install.
Build Platforms
| name | description |
|---|---|
| all (default) | Builds all of these platforms. |
| browser | Builds asm js browser version. |
| node | Builds node js version. |
| standalone | Runs webpack. |
| none | Does nothing. You can use the prepackaged libs. |