facebook/flow

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Adds static typing to JavaScript to improve developer productivity and code quality.

Stars: 22.3k
Forks: 1.9k
Open beginner issues: 0
Indexed issues: 510

Dominant language: Rust
License: MIT
Last GitHub push: Sep 15, 2026
Latest indexed: Sep 15, 2026
Contributing guide: Contributing guide
Code of conduct: Code of conduct
Beginner labels: good first issue help wanted
PR merge metrics: No merged PRs in 30d

Open All

510 open issues indexed

flow-upgrade does nothing Open

facebook/flow#5043 · 2 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Allow for methods that throw exceptions to work as predicate functions. Open

facebook/flow#5049 · 2 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Typing a rest property in object destructuring as a function argument Open

Typing: rest

facebook/flow#5060 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Cannot implement Iterable interface Open

iterators

facebook/flow#5063 · 3 comments · 5 reactions · 0 assignees · Indexed Sep 15, 2026
import type * as types from './types' Open

facebook/flow#5082 · 0 comments · 2 reactions · 0 assignees · Indexed Sep 15, 2026
Module declaration wildcards Open

declarations feature request

facebook/flow#5101 · 0 comments · 3 reactions · 0 assignees · Indexed Sep 15, 2026
Finding types from external dependencies when using Yarn workspaces Open

facebook/flow#5107 · 7 comments · 45 reactions · 0 assignees · Indexed Sep 15, 2026
Intersection of objects are not extendable with more properties or even queryable about other properties Open

facebook/flow#5142 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Uncovered Code from imported styles.css file Open

facebook/flow#5143 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Combination of switch case and refinement of possibly undefined variable doesn't work Open

facebook/flow#5145 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Unexpected type errors when wrapping a generic function type Open

facebook/flow#5149 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Flow library definition documentation should cover json files Open

documentation

facebook/flow#5150 · 2 comments · 2 reactions · 0 assignees · Indexed Sep 15, 2026
Still checking non-dependencies in node_modules Open

Windows support

facebook/flow#5164 · 7 comments · 14 reactions · 0 assignees · Indexed Sep 15, 2026
[React] Why is it recommended to mark the props in defaultProps as required? Open

facebook/flow#5173 · 6 comments · 7 reactions · 0 assignees · Indexed Sep 15, 2026
interfaces can no longer have constructors Open

facebook/flow#5208 · 10 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Typing result of function which is influenced by optional parameter Open

facebook/flow#5234 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Feedback request: use node tooling for checking Test262 tests? Open

discussion test262

facebook/flow#5247 · 2 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Allow return this in interface Open

feature request Typing: interfaces

facebook/flow#5250 · 4 comments · 2 reactions · 0 assignees · Indexed Sep 15, 2026
Problem with simple object destructuring and refinement Open

feature request

facebook/flow#5259 · 6 comments · 4 reactions · 0 assignees · Indexed Sep 15, 2026
interface vs type in typing React children Open

facebook/flow#5267 · 2 comments · 1 reaction · 0 assignees · Indexed Sep 15, 2026
Don't warn about untyped-type-import when importing from .js.flow file Open

facebook/flow#5278 · 0 comments · 9 reactions · 0 assignees · Indexed Sep 15, 2026
Exact object shapes lost after refinement Open

Typing: refinements

facebook/flow#5280 · 9 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Cannot type check code with a union type involving tuples. Open

facebook/flow#5281 · 4 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Feature request: No contradicting checks Open

feature request

facebook/flow#5299 · 1 comment · 1 reaction · 0 assignees · Indexed Sep 15, 2026
New type errors from Immutable.js after upgrading to Flow v0.59 Open

facebook/flow#5340 · 3 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Erroneous Unaccessible Property of Two Disjoint Union Types that are Intersections of Another Type Open

facebook/flow#5353 · 4 comments · 2 reactions · 0 assignees · Indexed Sep 15, 2026
[improvement suggestion] Disjoint type refinement over destructured properties Open

destructuring enhancement

facebook/flow#5370 · 0 comments · 1 reaction · 0 assignees · Indexed Sep 15, 2026
Intersection of object types with matching keys does not work as expected. Open

facebook/flow#5379 · 0 comments · 3 reactions · 0 assignees · Indexed Sep 15, 2026
Generic is not resolving properly in complex situation. Open

facebook/flow#5419 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Cannot test property exist on (A | (B & C)) type Open

facebook/flow#5422 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
link styles in docs Open

documentation

facebook/flow#5454 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
`module.system.node.resolve_dirname` is not used on dependent node modules that use flow. Open

facebook/flow#5459 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Any way to acknowledge "constant contexts" (e.g. string literal concatenation)? Open

facebook/flow#5460 · 0 comments · 1 reaction · 0 assignees · Indexed Sep 15, 2026
Disjoint Union Question Open

facebook/flow#5488 · 4 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
What are best practices for optional parameters? Open

facebook/flow#5490 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Callable Object Intersection with Function Open

facebook/flow#5497 · 0 comments · 1 reaction · 0 assignees · Indexed Sep 15, 2026
Inconsistent Flow errors when using object spread and intersections: Open

Typing: spread Typing: unions/intersections

facebook/flow#5499 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Flow type errors when building higher-order components using intersection types Open

facebook/flow#5500 · 0 comments · 2 reactions · 0 assignees · Indexed Sep 15, 2026
Ignore node_modules except @custom_namespace or dir Open

feature request

facebook/flow#5556 · 7 comments · 8 reactions · 0 assignees · Indexed Sep 15, 2026
%checks type refinement function for opaque alias types Open

Typing: opaque types Typing: refinements

facebook/flow#5563 · 1 comment · 1 reaction · 0 assignees · Indexed Sep 15, 2026
await/.then does not unwrap Promise<Promise<T>> Open

Typing: async/await

facebook/flow#5582 · 5 comments · 5 reactions · 0 assignees · Indexed Sep 15, 2026
Uint8Array.from 's `map` argument should define the type necessary for `source` Open

Library definitions

facebook/flow#5607 · 0 comments · 3 reactions · 0 assignees · Indexed Sep 15, 2026
The flow-upgrade tool deletes comments between class definition and props declaration Open

facebook/flow#5608 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Allow Ignore Refinement Invalidation checking for specified maybe variable/prop/member Open

facebook/flow#5614 · 0 comments · 1 reaction · 0 assignees · Indexed Sep 15, 2026
flowconfig [ignore] not working Open

facebook/flow#5641 · 10 comments · 1 reaction · 0 assignees · Indexed Sep 15, 2026
Infer types from JSDoc comments Open

feature request interned comments

facebook/flow#5670 · 6 comments · 19 reactions · 0 assignees · Indexed Sep 15, 2026
indexer intersection regression Open

regression

facebook/flow#5698 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Allow destructuring of all iterables Open

destructuring feature request iterators

facebook/flow#5701 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Symlinked library's .js.flow files are ignored Open

declarations

facebook/flow#5736 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Flow's linter complains that JSON files are untyped Open

bug

facebook/flow#5749 · 6 comments · 17 reactions · 0 assignees · Indexed Sep 15, 2026

facebook/flow

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