Likely to cause new Flow errors:
- Improved generic type inference with conditional types. Some places might infer a different type and cause new errors.
Number,String,RegExp,Date, native errors, maps, and sets now use TypeScript-style instance and constructor interfaces, while Math, JSON, and Atomics use named interfaces. Existing code relying on their previous class or object typing may produce new errors.
New Features:
- Allow object type spreads over interfaces and inexact object types.
Notable bug fixes:
- Allow classes to extend generic construct-signature interfaces.
- Generic values re-exported through annotated CommonJS getters retain their polymorphic types.
- Preserve record lowering source locations.
- Preserve match lowering source locations.
Parser:
- Support semicolonless abstract method declarations.