f00116c3a6
Summary: In D17439957, I noted that YogaLogger#log throws a NoMethodFoundException when called from C++ b/c C++ and Java's signatures of that method don't match. C++ uses YogaNodeJNIBase for the first param, Java uses YogaNode. Both my attempts to fix this failed. Attempt #1 - Make Java use YogaNodeJNIBase. This doesn't work because the :java-interface target includes YogaLogger but not YogaNodeJNIBase. Moving YogaLogger to the impl target doesn't work either b/c other files in :java-interface reference YogaLogger. Attempt #2 - Make C++ use YogaNode. This doesn't work b/c we try to call the log method with objects of fbjni type YogaNodeJNIBase. This would be fine in Java since YogaNodeJNIBase extends YogaNode. But fbjni's typing isn't advanced enough to know this, so the Yoga C++ fails to compile. At this point, I was wondering what the value of having this param in the log function at all was. None of the implementations in our codebase use it today. It might be easier to just remove it all together. This also removes a bug with YGNodePrint where we pass a null layout context that eventually causes a SIG_ABRT when we use it to try to find a YogaNode to pass to this function. (https://fburl.com/diffusion/ssw9h8lv). Reviewed By: amir-shalem Differential Revision: D17470379 fbshipit-source-id: 8fc2d95505971a52af2399a9fbb60b63f27f0ec2
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. |