9b96a5362a
Summary: This pull request adds `YGNode.h` and `YGStyle.h` to the headers exported by Yoga's podspec. They are required by the new Fabric architecture of React Native. The modulemap and its umbrella header automatically generated by Cocoapods adds all exported headers to the `modulemap`. Having YGNode and YGStyle exported through here has problems, because they are only available in environments that have C++ available, and will produce errors otherwise. This pull request fences off the contents of those headers in an `#ifdef __cplusplus` block, so they will not cause errors when imported into environments where C++ isn't available. I had considered adding a custom modulemap to the podspec as part of this pull request, but this way seems the least "invasive", and this way you are able to add and remove exported headers in the podspec without needing to worry about updating the umbrella header at the same time. Changelog: [Internal] - Yoga Podspec: Export YGNore and YGStyle headers Pull Request resolved: https://github.com/facebook/yoga/pull/997 Reviewed By: hramos Differential Revision: D20966075 Pulled By: mdvacca fbshipit-source-id: 5f5caa6b639d11e660b968d681da9a4de6c0eb8e
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 generate 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. |