facebook/flow v0.203.0

on GitHub

Likely to cause new Flow errors:

• $Partial has been renamed to Partial, use the latter instead. Read the blog post for more details.
• Support for inference_mode config and related infra such as codemods were removed. You should follow the instructions in the Local Type Inference for Flow blog post to switch to use LTI before upgrading if you haven't already done so.
• We replaced the implementation which checks nested $Call and $ObjMap during the check of a polymorphic function call. As a result, more underconstrained errors or type incompatibility errors might appear.
• Removed the sharedmemory.log_level flowconfig option and the --sharedmemory-log-level command line option.

IDE:

• Implement linked editing for JSX elements.
• Added code actions for adding/removing braces from arrow functions.
• Adds a quick fix from the deprecated $Partial to Partial.

Notable bug fixes:

• Fixed a bug that caused instances of nested utility types to be considered equivalent to empty. e.g. try Flow example.
• Make Flow's behavior more consistent by not erroring on .constructor accesses. e.g. try Flow example.
• Fixed the file watcher not reacting to any changes on Windows.
• Improve the error messages when underconstrained-implicit-instantiation errors are raised in overloaded function calls. e.g. try Flow example
• We now propagate any to instance types' type arguments. As a result, some spurious errors under LTI might be fixed (e.g. try Flow example), and some new errors might be revealed.
• Fixed the hover type result when an enum object type appears nested in another type structure. e.g. try Flow example.
• Fixed the hover type on certain kinds of union types. e.g. try Flow example.
• Fixed the hover type on class constructors.

Misc:

• Try Flow's behavior can now be configured.

Parser:

• Leading (, & and | are now included in intersection and union ranges, respectively.
• Improve error recovery for mismatched JSX tags.

Library Definitions:

• Change setState in React lib defs to use $ReadOnly<Partial<T>> instead of $Shape<T>.
• Make $ReadOnlySet entry type covariant.
• Expand the Performance typing with the eventCounts property, according to the W3C standard.
• Adjust the type definitions of the mark and measure properties on Performance interface according to the W3C standard.