90df05c4f3
Summary: Pull Request resolved: https://github.com/facebook/yoga/pull/1506 In order to build the website, you must build a Yoga binary. This usually requires installing native toolchains. We have warning messages for these right now, but an even better solution is to just manage the dependencies ourselves. This does that, bringing in specific CMake and Ninja binaries from NPM, and caching a local copy of Emscripten during the build. A downside is that the CMake packages are chunky, so we add 130MB to node_modules (for a repo total around 350MB). This also delays acquiring Emscripten (which is even chunkier) in CI builds until it is needed, and I added some caching for it as well. The upside of JS users being able to run and test (inc the website) without installing and managing their own versions of toolchains is a real time-saver though, and is probably worth it. Differential Revision: D52013026 fbshipit-source-id: 9b974bea1f13d46a5949ff7c84cccab04e199340
Yoga 
Yoga is an embeddable and performant flexbox layout engine with bindings for multiple languages.
Building
Yoga's main implementation targets C++ 20 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 If the version is out of date, please create an issue or pull request on the vcpkg repository.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).