microsoft/TypeScript

View on GitHub

TypeScript is a superset of JavaScript that compiles to clean JavaScript output.

Stars: 111k
Forks: 14.3k
Open beginner issues: 18
Indexed issues: 4.9k
Avg merge: 2d 4h
Merged PRs (30d): 132

Dominant language: Go
License: Apache-2.0
Last GitHub push: Sep 18, 2026
Latest indexed: Sep 19, 2026
Contributing guide: Contributing guide
Code of conduct: Code of conduct
Beginner labels: help wanted good first issue

Beginner friendly Everything

Open All

4,857 issues indexed so far

Wrong inference for defaulted generic in nested call Open

Bug Domain: check: Type Inference

Difficulty 4/5 3-5 days Newbie friendliness 45/100

microsoft/TypeScript#63380 · 1 comment · 1 reaction · Opened Apr 9, 2026
Object properties are inferred in the wrong order: should infer properties with `NoInfer<T>` AFTER properties with `T` Open

Domain: check: Type Inference Possible Improvement

Difficulty 4/5 3-5 days Newbie friendliness 42/100

microsoft/TypeScript#63378 · 2 comments · Opened Apr 9, 2026
TS2589 regression in 6.0: implements without type parameters causes excessive type instantiation when property uses concrete generic type Open

Fixed

Difficulty 4/5 3-5 days Newbie friendliness 35/100

microsoft/TypeScript#63376 · 5 comments · Opened Apr 8, 2026
No project found for untitled file Open

microsoft/TypeScript#63812 · 3 comments · 1 reaction · 4 assignees · Opened Apr 8, 2026
Typescript Server syntax highlighting bug: introduced by recent update Open

microsoft/TypeScript#63382 · 3 comments · 3 reactions · 1 assignee · Opened Apr 8, 2026
Add a `redeclare` keyword to redeclare class attributes, behaving like `override !:` while keeping type modifiers. Open

Awaiting More Feedback Suggestion

Difficulty 5/5 Over a week Newbie friendliness 35/100

microsoft/TypeScript#63370 · 2 comments · 2 reactions · Opened Apr 7, 2026
Inside a generic function with a remapped type as parameter, elements are wrongfully inferred as {}. Open

Needs Investigation

Difficulty 4/5 3-5 days Newbie friendliness 45/100

microsoft/TypeScript#63363 · 4 comments · Opened Apr 6, 2026
TSX error location error with location and JSX comment Open

Bug Domain: JSX/TSX Needs Human Review Needs More Info

Difficulty 3/5 1-2 days Newbie friendliness 55/100

microsoft/TypeScript#63358 · 3 comments · Opened Apr 6, 2026
Error on function return is less useful than it should be Open

Domain: check: Contextual Types Possible Improvement

Difficulty 5/5 Over a week Newbie friendliness 45/100

microsoft/TypeScript#63357 · 1 comment · Opened Apr 5, 2026
TS IntelliSense is very slow or loads endlessly on simple ArkType wrapper Open

Needs Investigation

Difficulty 4/5 3-5 days Newbie friendliness 45/100

microsoft/TypeScript#63452 · 3 comments · 2 reactions · Opened Apr 4, 2026
type checking complexity with multiple template literals in unions Open

Domain: check: Big Unions Experimentation Needed Possible Improvement

Difficulty 4/5 3-5 days Newbie friendliness 48/100

microsoft/TypeScript#63342 · 5 comments · Opened Apr 2, 2026
Playground typing issue Open

Website

Difficulty 4/5 3-5 days Newbie friendliness 42/100

microsoft/TypeScript#63334 · 1 comment · Opened Apr 2, 2026
Missing `removeUnused` code fix/code action Open

microsoft/TypeScript#63811 · 2 comments · 3 reactions · 1 assignee · Opened Apr 1, 2026
Missing `fixAll` code action/code fix Open

microsoft/TypeScript#63810 · 2 comments · 1 reaction · 1 assignee · Opened Apr 1, 2026
Missing `addMissingImports` code action/code fix Open

microsoft/TypeScript#63809 · 5 comments · 13 reactions · 1 assignee · Opened Apr 1, 2026
[V6] `module` defaults is not `esnext` Open

Docs

microsoft/TypeScript#63330 · 7 comments · 5 reactions · 1 assignee · Opened Apr 1, 2026
TSGO: command 'typescript.restartTsServer' not found Open

Possible Improvement

microsoft/TypeScript#63808 · 4 comments · 19 reactions · 1 assignee · Opened Mar 31, 2026
importModuleSpecifier "shortest" does not choose shortest result among multiple matching paths aliases Open

Awaiting More Feedback Suggestion

Difficulty 4/5 3-5 days Newbie friendliness 52/100

microsoft/TypeScript#63320 · 2 comments · Opened Mar 30, 2026
Allow structural typing of prototypes Open

Awaiting More Feedback Suggestion

Difficulty 5/5 Over a week Newbie friendliness 25/100

microsoft/TypeScript#63314 · 2 reactions · Opened Mar 28, 2026
Proposal: Flatten the AST to speed up tsgo Open

Possible Improvement

Difficulty 5/5 Over a week Newbie friendliness 25/100

microsoft/TypeScript#63807 · 5 comments · 1 reaction · Opened Mar 27, 2026
Reimplement "find file references" Open

Needs Investigation

microsoft/TypeScript#63806 · 5 reactions · 1 assignee · Opened Mar 26, 2026
Report perf measurements from extension Open

Possible Improvement

Difficulty 5/5 Over a week Newbie friendliness 25/100

microsoft/TypeScript#63805 · Opened Mar 26, 2026
Track file type or extension for failing requests Open

Possible Improvement

microsoft/TypeScript#63804 · 1 reaction · 2 assignees · Opened Mar 25, 2026
Custom syntax for distributive conditional Open

Awaiting More Feedback Suggestion

Difficulty 5/5 Over a week Newbie friendliness 28/100

microsoft/TypeScript#63295 · 9 comments · Opened Mar 24, 2026
RegExpIndicesArray - Named group indices can be undefined Open

Awaiting More Feedback Suggestion

Difficulty 3/5 1-2 days Newbie friendliness 68/100

microsoft/TypeScript#63281 · 4 comments · 1 reaction · Opened Mar 22, 2026
[Localization] Misleading Chinese translation for TS2561 error message Open

Bug Domain: Error Messages i18n

Difficulty 2/5 1-3 hours Newbie friendliness 75/100

microsoft/TypeScript#63274 · 2 comments · Opened Mar 20, 2026
Crash: RangeError: Maximum call stack size exceeded in getNameOfSymbolAsWritten via recursive conditional ReturnType Open

Bug Domain: check: Type Circularity

Difficulty 4/5 3-5 days Newbie friendliness 48/100

microsoft/TypeScript#63273 · 1 comment · Opened Mar 20, 2026
Crash: RangeError: Invalid string length in addSpans during instantiation of recursive template literal types Open

Bug Domain: Crashes

Difficulty 4/5 3-5 days Newbie friendliness 45/100

microsoft/TypeScript#63271 · Opened Mar 19, 2026
Mechanism to specify input source location to find `package.json` instead of output source location when determining module format Open

Needs Proposal Suggestion

Difficulty 4/5 3-5 days Newbie friendliness 35/100

microsoft/TypeScript#63251 · 3 comments · 1 reaction · Opened Mar 14, 2026
Bloomberg feedback for 6.0 Open

Discussion

Difficulty 5/5 Over a week Newbie friendliness 20/100

microsoft/TypeScript#63245 · 2 comments · 2 reactions · Opened Mar 12, 2026
bug(lib): Explicitly stating wrong return type of `Promise.then` without arguments results in no error Open

Needs Proposal

Difficulty 4/5 3-5 days Newbie friendliness 35/100

microsoft/TypeScript#63244 · 5 comments · 1 reaction · Opened Mar 12, 2026
Error from `exactOptionalPropertyTypes` not reported when using object spread with a ternary and optional property acces Open

Bug Domain: flag: exactOptionalPropertyTypes

Difficulty 3/5 1-2 days Newbie friendliness 45/100

microsoft/TypeScript#63240 · 1 comment · Opened Mar 11, 2026
Compiler crash: Debug Failure in visitEachChildOfIndexSignatureDeclaration Open

Bug Domain: Crashes

Difficulty 3/5 1-2 days Newbie friendliness 48/100

microsoft/TypeScript#63230 · 3 comments · Opened Mar 10, 2026
Inference from result of generic function no longer produces a union Open

Needs Investigation

microsoft/TypeScript#63227 · 1 comment · 1 assignee · Opened Mar 10, 2026
`Omit` causes function to lose contextual typing Open

Needs Investigation

Difficulty 4/5 3-5 days Newbie friendliness 48/100

microsoft/TypeScript#63225 · 2 comments · Opened Mar 9, 2026
Toggling `isolatedModules` in `tsconfig.json` while running the compiler in `watch` mode, doesn't re-emit `const enums`, unlike toggling `preserveConstEnums`, which does Open

Bug Domain: flag: isolatedDeclarations

Difficulty 4/5 3-5 days Newbie friendliness 38/100

microsoft/TypeScript#63223 · 1 comment · Opened Mar 8, 2026
Allow primitive LHS to `instanceof` operator if RHS is a custom `hasInstance` Open

Awaiting More Feedback Suggestion

Difficulty 3/5 1-2 days Newbie friendliness 58/100

microsoft/TypeScript#63219 · 2 comments · 2 reactions · Opened Mar 7, 2026
Error (2320) when extending interfaces where a property is both readonly and readwrite. Open

Awaiting More Feedback Suggestion

Difficulty 5/5 Over a week Newbie friendliness 25/100

microsoft/TypeScript#63218 · 4 comments · Opened Mar 7, 2026
Google feedback on TS 6.0-beta Open

Discussion

Difficulty 5/5 Over a week Newbie friendliness 20/100

microsoft/TypeScript#63214 · 2 comments · 4 reactions · Opened Mar 6, 2026
Add JSX.ElementChildrenAttribute change to TypeScript 5.8 release notes Open

Docs

Difficulty 2/5 1-3 hours Newbie friendliness 68/100

microsoft/TypeScript#63212 · 1 comment · Opened Mar 4, 2026
Missing auto-import for subpath imports of other local packages Open

microsoft/TypeScript#63803 · 6 comments · 1 assignee · Opened Mar 4, 2026
6.0.20260301 Causing general instability and hanging operations Open

Needs More Info

Difficulty 4/5 3-5 days Newbie friendliness 25/100

microsoft/TypeScript#63210 · 1 comment · 1 reaction · Opened Mar 3, 2026
tsserver hangs indefinitely when inferring return type of class method that passes this to a function with deeply nested conditional return type Open

Bug Domain: check: Type Circularity

Difficulty 5/5 Over a week Newbie friendliness 35/100

microsoft/TypeScript#63207 · 3 comments · Opened Mar 2, 2026
Confusing error message (2322), should use (2741) and (2322) error message when this["XXX"] = {...} has a missing (or mispelled) key or an incompatible value. Open

Bug Domain: Error Messages Help Wanted

Difficulty 4/5 3-5 days Newbie friendliness 45/100

microsoft/TypeScript#63206 · 13 comments · Opened Mar 2, 2026
Crash: TypeError: Cannot read properties of undefined (reading 'aliasSymbol') remains when using variadic tuple with (infer C)[] and constrained infer Open

Bug Domain: Crashes

Difficulty 4/5 3-5 days Newbie friendliness 45/100

microsoft/TypeScript#63199 · 5 comments · Opened Feb 27, 2026
Debug Failure: "No error for last overload signature" crash when CustomTypeOptions.resources uses typeof on a large (~10k line) JSON file Open

Needs More Info

Difficulty 4/5 3-5 days Newbie friendliness 48/100

microsoft/TypeScript#63195 · 6 comments · 1 reaction · Opened Feb 26, 2026
🚀 Proposal: Cross-Context Function Annotation (for APIs like `page.evaluate` of playwright) Open

Awaiting More Feedback Suggestion

Difficulty 5/5 Over a week Newbie friendliness 25/100

microsoft/TypeScript#63194 · 3 comments · 2 reactions · Opened Feb 26, 2026
Incorrect reference `this` in static context with `experimentalDecorators` enabled Open

Bug Domain: Decorators

Difficulty 4/5 3-5 days Newbie friendliness 38/100

microsoft/TypeScript#63189 · 3 comments · Opened Feb 24, 2026
tsgo producing source maps that cause functions to appear uncovered in tests Open

Bug Domain: Source Maps Needs Human Review Needs More Info

microsoft/TypeScript#63185 · 2 comments · 1 reaction · 1 assignee · Opened Feb 23, 2026
exports subpath with array types is not autocompleting Open

Needs More Info

Difficulty 3/5 1-2 days Newbie friendliness 54/100

microsoft/TypeScript#63231 · 5 comments · Opened Feb 22, 2026

microsoft/TypeScript

Get new issues in your inbox