v0.324.0

New Features:

• .flowconfig's [include] and [ignore] sections can now be configured using globs, in addition to the current regex based system. Right now, glob items must be specified with glob: prefix. Globs do not support <PROJECT_ROOT>, since they are assumed to start from the project root.
• Class fields and methods whose computed key resolves to a literal string or number are now supported and type-checked as named members.

v0.323.0

No behavioral changes in this release

v0.322.0

Notable bug fixes:

• Fixed #9448
• Fixed a crash in pattern matching. (example)
• Refining a union by instanceof no longer leaks any from members that cannot match the guard (e.g. Foo<string> | Bar<number> refined by instanceof Foo now yields Foo<string> instead of Foo<string> | Foo<any>). This may surface real errors that were previously masked.

v0.321.0

Parser:

• flow-parser is now backed by the Rust port parser. It will have public API similar to that of hermes-parser.

v0.320.0

Likely to cause new Flow errors:

• Object operations on class instance types now produce plain object types instead of preserving the class instance's nominal identity. This affects object type spreads and utilities such as Partial, Required, Readonly, Pick, and Omit. Example

v0.319.0

Likely to cause new Flow errors:

• The config for casting_syntax is removed. The as casting syntax is the only supported casting syntax. See Modernizing legacy syntax for migration guidance.
• Flow will now error on T: B in favor of T extends B in type parameters, and error on +/- in favor of readonly/writeonly . See Modernizing legacy syntax for migration guidance.

New Features:

• Support the global NaN as a match pattern

Notable bug fixes:

• Fixed negative bigint literal patterns in match being treated as their positive counterpart
• ConstructorParameters and InstanceType now work on Class<C>, not just typeof C
• match instance patterns whose constructor is a subclass of the scrutinee type are no longer incorrectly reported as unused.

v0.318.0

Likely to cause new Flow errors:

• Flow will now error on all deprecated utility types. See Modernizing legacy syntax for migration guidance.

v0.317.0

New Features:

• Allow -? (optionality removal) in mapped types.
• Adds support for utility types ConstructorParameters and InstanceType

Misc:

• The .flowconfig options component_syntax, enums, and pattern_matching now default to true. To keep the previous behavior, set the corresponding option to =false in your .flowconfig.

v0.316.0

Likely to cause new Flow errors:

• deprecated-type and deprecated-type-bool errors are now always on (the lints were on by default already). Update any references of the type bool to boolean, and delete references to the lints in your .flowconfig and flowlint comments — the setting is a no-op for this release and will be removed in a future release.

[flow] v0.315.0

• Variance keywords (readonly, writeonly, in, out) on type parameters and object/class properties are now enabled by default. The experimental.allow_variance_keywords is no longer needed to opt in.
• The deprecated variance sigils error message now suggests the contextually correct keyword (readonly/writeonly for property positions, out/in for type parameter positions) instead of listing both alternatives.