Add data-disabled to test fixtures (#1286)

Summary:
Pull Request resolved: https://github.com/facebook/yoga/pull/1286

This can be marked in fixtures to skip a test without commenting it out. We add one more usage of this.

The same functionality existed (unused) before for `experiments`, which I changed to `data-experiments`.

Formatting of JS tests changed to be closer to what Prettier would output, and to remove usage of `Yoga.UNDEFINED` which doesn't existi and just resolves to `undefined` (this is converted to NaN by the wrapper layer).

Reviewed By: yungsters

Differential Revision: D45723003

fbshipit-source-id: 337af319ab1c1c12047d6579da8c7e63b4f1537a

gentest/gentest-java.js

@@ -44,6 +44,7 @@ JavaEmitter.prototype = Object.create(Emitter.prototype, {
       '',
       'import static org.junit.Assert.assertEquals;',
       '',
+      'import org.junit.Ignore;',
       'import org.junit.Test;',
       'import org.junit.runner.RunWith;',
       'import org.junit.runners.Parameterized;',
@@ -67,8 +68,11 @@ JavaEmitter.prototype = Object.create(Emitter.prototype, {
     ]);
   }},
 
-  emitTestPrologue:{value:function(name, experiments) {
+  emitTestPrologue:{value:function(name, experiments, disabled) {
     this.push('@Test');
+    if (disabled) {
+      this.push('@Ignore');
+    }
     this.push('public void test_' + name + '() {');
     this.pushIndent();