test262/FEATURES.md

Feature Flags

Current, post-ES2015, flags used to identify new features:

• async-functions: Async Functions
• async-iteration: Async Iteration and Generators
• object-rest: Object rest/spread properties
• object-spread: Object rest/spread properties
• regexp-dotall: RegExp s (dotAll) flag
• regexp-lookbehind: RegExp lookBehind
• regexp-named-groups: RegExp named groups capturing
• regexp-unicode-property-escapes: RegExp Unicode Property Escapes
• SharedArrayBuffer
• Symbol.asyncIterator

While it's mostly optional when already in a current released specification, it's highly recommended to reuse the features flags for any matching case in new tests.