GitHub workflow to ensure tests are up to date (#1505)

Summary:
Pull Request resolved: https://github.com/facebook/yoga/pull/1505

This will ensure that all tests are not modified by hand and that gentest was run if needed (i.e. someone edited those files and forgot to update the tests). Not sure if this works right now, need to export to github and see what happens :)

Reviewed By: NickGerleman

Differential Revision: D52002920

fbshipit-source-id: 1ee033eda04eeba5d01885488bfe8078e7b2f386

gentest/gentest-driver.ts

@@ -31,6 +31,7 @@ function addSignatureToSourceCode(sourceCode: string): string {
 const argv = minimist(process.argv.slice(2));
 const specificFixture = argv.f || argv.fixture;
 const suspend = argv.s || argv.suspend;
+const headless = argv.h || argv.headless;
 
 const gentestDir = dirname(fileURLToPath(import.meta.url));
 const yogaDir = dirname(gentestDir);
@@ -54,6 +55,7 @@ options.addArguments(
   '--window-position=0,0',
   '--hide-scrollbars',
 );
+headless && options.addArguments('--headless');
 options.setLoggingPrefs({
   browser: 'ALL',
   performance: 'ALL',