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

JSX embedded tags Open

feature request react

facebook/flow#7546 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Right-hand side of `instanceof` does not have to be callable Open

bug

facebook/flow#7553 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Class statics doesn't get inherited in $ReadOnly Open

bug Typing: destructors

facebook/flow#7572 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
React.createElement is unsound with inexact configs Open

bug Typing: soundness

facebook/flow#7582 · 0 comments · 0 reactions · 1 assignee · Indexed Sep 15, 2026
Reduce Priority of Flow LS Open

discussion

facebook/flow#7589 · 0 comments · 2 reactions · 0 assignees · Indexed Sep 15, 2026
Invalid error produced between super and child classes Open

bug needs triage

facebook/flow#7611 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Improve support of property existance checking Open

enhancement Typing: refinements

facebook/flow#7619 · 9 comments · 11 reactions · 0 assignees · Indexed Sep 15, 2026
Disjoint union type for React props does not work. Open

bug Typing: completeness

facebook/flow#7623 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Flow doesn't propagate refinement information through variable Open

feature request

facebook/flow#7629 · 1 comment · 3 reactions · 0 assignees · Indexed Sep 15, 2026
Why both extension='scss' and extension='module.scss' not worked? Open

question

facebook/flow#7636 · 7 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
How set module.name_mapper for mapping to .scss.module files? Open

question

facebook/flow#7638 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Cannot resolve JSON file starting with a dot Open

bug good first issue Has PR module resolution

facebook/flow#7673 · 13 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
flow generates invalid utf-8 output in JSON Open

bug

facebook/flow#7690 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Flow refine a union type between arguments and return value of a function Open

discussion

facebook/flow#7695 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Top-level await Open

discussion ES2015+

facebook/flow#7710 · 1 comment · 13 reactions · 0 assignees · Indexed Sep 15, 2026
Autocompletion/suggestions on imported or inherited types not happening Open

autocomplete bug

facebook/flow#7722 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Refining to an array no longer allows me to edit the array using splice Open

enhancement Typing: refinements

facebook/flow#7731 · 7 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Object.freeze on an array should result in a read-only array Open

feature request

facebook/flow#7733 · 2 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
flow-remove-types produces invalid JS after non-latin characters Open

bug parsing

facebook/flow#7779 · 13 comments · 4 reactions · 0 assignees · Indexed Sep 15, 2026
Support extra `filter` and `every` type refinement Open

feature request Typing: refinements

facebook/flow#7793 · 3 comments · 3 reactions · 0 assignees · Indexed Sep 15, 2026
autocomplete doesn't work with `export { foo } from './some-file'` Open

autocomplete bug

facebook/flow#7797 · 6 comments · 0 reactions · 1 assignee · Indexed Sep 15, 2026
Change default max heap size to 1/4 of physical memory Open

discussion nontermination / perf

facebook/flow#7819 · 7 comments · 0 reactions · 1 assignee · Indexed Sep 15, 2026
$PropertyType lookups on class parameters allows variance abuse to sneak through class method checking Open

bug Typing: property variance Typing: soundness

facebook/flow#7830 · 0 comments · 1 reaction · 0 assignees · Indexed Sep 15, 2026
Union speculation error message regression Open

bug error messages regression Typing: unions/intersections

facebook/flow#7884 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
[Summary] Flowtype / VSCode pain points and potential improvements Open

discussion LSP Meta Issue

facebook/flow#7918 · 4 comments · 9 reactions · 0 assignees · Indexed Sep 15, 2026
Incorrect props Infer error when used Intersection types as template parameter in React.ComponentType Open

bug needs triage react Typing: unions/intersections

facebook/flow#7946 · 3 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Building a disjoint union fails in simple situation Open

bug Typing: unions/intersections

facebook/flow#7956 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Cannot resolve module from external project Open

bug needs triage

facebook/flow#7963 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
React.memo can't be used with intersection type props from v0.99 Open

bug needs triage react Typing: unions/intersections

facebook/flow#7975 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Vim/Emacs integration docs reference archived projects Open

documentation

facebook/flow#7986 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Unicode in type-at-pos is broken Open

bug parsing type-at-pos

facebook/flow#8013 · 3 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Wrong error position with generic application Open

bug error messages Typing: polymorphism

facebook/flow#8019 · 0 comments · 1 reaction · 0 assignees · Indexed Sep 15, 2026
Errors on accessing indexed properties on object without prototype Open

bug Typing: object model

facebook/flow#8030 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Its confusing that object maps require ... (they are not exact) Open

discussion

facebook/flow#8039 · 4 comments · 1 reaction · 0 assignees · Indexed Sep 15, 2026
Better error messages for incompatibilities due to variance Open

discussion error messages

facebook/flow#8041 · 1 comment · 0 reactions · 1 assignee · Indexed Sep 15, 2026
[flow-remove-types] Output is corrupted by \u2019 characters Open

bug remove-types

facebook/flow#8060 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Error message when trying to call a class as a function is confusing Open

discussion error messages

facebook/flow#8062 · 0 comments · 11 reactions · 1 assignee · Indexed Sep 15, 2026
Conditional refinement doesn't work as expected Open

feature request Typing: refinements

facebook/flow#8074 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
delete super.name shouldn't work Open

bug Typing: soundness

facebook/flow#8101 · 2 comments · 2 reactions · 0 assignees · Indexed Sep 15, 2026
delete check has misleading error message Open

bug needs triage

facebook/flow#8116 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Problem with React Component and Union Type props Open

bug needs triage

facebook/flow#8125 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Warning message when flow is parsing large json files Open

feature request

facebook/flow#8129 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Disallow intersection of exact objects Open

discussion

facebook/flow#8158 · 3 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Export a generic list of html elements Open

discussion

facebook/flow#8173 · 0 comments · 1 reaction · 0 assignees · Indexed Sep 15, 2026
Function Generic parameter is resolved to void Open

bug Typing: functions

facebook/flow#8190 · 2 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Add max_warnings config option to `.flowconfig` file Open

discussion

facebook/flow#8240 · 0 comments · 4 reactions · 0 assignees · Indexed Sep 15, 2026
Intersection Types Unexpected error Open

bug Typing: object model Typing: unions/intersections

facebook/flow#8250 · 1 comment · 0 reactions · 0 assignees · Indexed Sep 15, 2026
Intersection of intersections doesn't cast to itself after spreading Open

bug Typing: unions/intersections

facebook/flow#8257 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
resolve_dirname doesn't work for parent folders Open

module resolution question

facebook/flow#8271 · 0 comments · 0 reactions · 0 assignees · Indexed Sep 15, 2026
LSP: Unused suppression comment warning disappears after first edit Open

bug LSP needs triage

facebook/flow#8282 · 4 comments · 5 reactions · 0 assignees · Indexed Sep 15, 2026

facebook/flow

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