01c0c4ed3b
Summary: Pull Request resolved: https://github.com/facebook/yoga/pull/1256 X-link: https://github.com/facebook/react-native/pull/37076 This adds a `YGErrata` bitset enum matching the API and guarantees described in https://github.com/facebook/yoga/issues/1247. It is hooked up in later diffs. There are a couple of `YGExperimentalFeature` values that belong here, but keeping the current options means that the default `YGErrataNone` corresponds to existing default behavior, letting us stage the series of changes as: 1. Implement errata API 2. Update internal Yoga users we want to de-risk to `YGErrataClassic` or `YGErrataAll` (if setting `UseLegacyStretchBehaviour`) 3. Add new errata, changing Yoga defaults to be conformant, while letting internal apps opt into compatibility modes pending experimentation. I also added a macro to let C++ users of Yoga perform bitwise operations on the enum without casting (already available for C users). Reviewed By: rshest Differential Revision: D45254098 fbshipit-source-id: d4b61271a8018f548f2d9d8c953db4b121a502d1
Yoga 
Yoga is an embeddable and performant flexbox layout engine with bindings for multiple languages.
Building
Yoga's main implementation targets C++ 14 with accompanying build logic in CMake. A wrapper is provided to build the main library and run unit tests.
./unit_tests <Debug|Release>
While not required, this script will use ninja if it is installed for faster builds.
Yoga is additionally part of the vcpkg collection of ports maintained by Microsoft and community contributors. If the version is out of date, please create an issue or pull request on the vcpkg repository.
Adding Tests
Many of Yoga's tests are automatically generated, using HTML fixtures describing node structure. These are rendered in Chrome to generate an expected layout result for the tree. New fixtures can be added to gentest/fixtures.
<div id="my_test" style="width: 100px; height: 100px; align-items: center;">
<div style="width: 50px; height: 50px;"></div>
</div>
To generate new tests from added fixtures:
- Run
bundle installin thegentestdirectory to install dependencies of the test generator. - Run
ruby gentest.rbin thegentestdirectory.
Debugging
Yoga provides a VSCode "launch.json" configuration which allows debugging unit tests. Simply add your breakpoints, and run "Debug C++ Unit tests (lldb)" (or "Debug C++ Unit tests (vsdbg)" on Windows).