aeffaf93a7
Summary:
Enums are currently exposed to the JS package as constants (e.g. `import {ERRATA_NONE} from 'yoga-layout'`).
This exports enums in the form of `import {Errata} from 'yoga-layout'` then `Errata.None`.
It would be more ergonomic for these to be string union based enums instead, but right now it is a pretty thin wrapper around the native API, we need ordinal values to do things with bit masks, and folks have wanted to serialize them before.
Differential Revision: https://internalfb.com/D45570417
fbshipit-source-id: c9c40f4b4dd6cb0c46bc05e558dded39dd299cf0
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 If the version is out of date, please create an issue or pull request on the vcpkg repository.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).