Review Board 3 and up support the ES6 standard for our JavaScript files. These are allowed in *.es6.js or *.ts files. This code will be transpiled to a more widely-supported subset of JavaScript through a third-party tool called Babel (see JavaScript Stack).

Not all ES6 features can easily be transpiled cleanly. Many end up leaving a lot of bloat in the resulting files, increasing file sizes and increasing runtime. Because of this, we've assembled a list of ES6 features we recommend for new code, ones we allow, ones we do not recommend, and ones we're actively avoiding (along with why).

These recommendations will change over time as new features are introduced and as our browser compatibility changes.

See Also:

• http://es6-features.org/ - Feature tour of ES6
• https://babeljs.io/repl/ - View the transpiled output of ES6 code using Babel

ChangeLog

Review Board 5+

The following have been moved to “Recommended”:

• Map, Set, WeakMap, WeakSet
• Rest arguments for functions
• Property key shorthand
• Spread operator
• Computed property names
• Destructuring