microsoft/TypeScript

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

Stars: 111k
Forks: 14.4k
Open beginner issues: 18
Indexed issues: 4.9k
Avg merge: 1d 19h
Merged PRs (30d): 117

Dominant language: Go
License: Apache-2.0
Last GitHub push: Sep 19, 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

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4,855 open issues indexed

Formatter: indent second operand of intersection operator on next line one indent more Open

Awaiting More Feedback Domain: Formatter Suggestion

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

microsoft/TypeScript#56609 · Opened Oct 19, 2023
This 1 line of TS code makes the editor unusable, cpu 100% Open

Needs Investigation

microsoft/TypeScript#56159 · 4 comments · 1 assignee · Opened Oct 19, 2023
IntelliSense not functioning in large project sometimes Open

Needs More Info

Difficulty 4/5 3-5 days Newbie friendliness 30/100

microsoft/TypeScript#56155 · 4 comments · Opened Oct 19, 2023
Unable to invoke an arrow function with an assertion predicate Open

In Discussion Suggestion

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

microsoft/TypeScript#56147 · 2 comments · 1 reaction · Opened Oct 18, 2023
No error when using arrow function as right operand of `instanceof` Open

Awaiting More Feedback Suggestion

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

microsoft/TypeScript#56143 · 10 comments · Opened Oct 18, 2023
Proposal: `decoratedWith` type operator and generic 'value' parameters Open

Awaiting More Feedback Suggestion

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

microsoft/TypeScript#56124 · 6 comments · Opened Oct 16, 2023
Incorrect narrowing of Union type after discrimination when one type is assignable to the other (even when explicit type annotation is present) Open

Bug Domain: check: Control Flow Help Wanted

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

microsoft/TypeScript#56106 · 17 comments · 1 reaction · Opened Oct 13, 2023
JSDoc doesnt support generics correctly Open

Needs Proposal Suggestion

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

microsoft/TypeScript#56102 · 5 comments · 24 reactions · Opened Oct 13, 2023
Unrelated interface causes assignability to change Open

Needs Investigation

microsoft/TypeScript#56099 · 2 comments · 3 reactions · 1 assignee · Opened Oct 13, 2023
Refinement type inference quirk with implicitly typed `let x` Open

Bug Domain: check: Control Flow Help Wanted

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

microsoft/TypeScript#56097 · 5 comments · Opened Oct 13, 2023
Supply label names in tuple types using type-level strings Open

Awaiting More Feedback Suggestion

Difficulty 5/5 Over a week Newbie friendliness 30/100

microsoft/TypeScript#56093 · 6 comments · 9 reactions · Opened Oct 12, 2023
jsdoc in JS: arguments object does not infer types from the containing function Open

Awaiting More Feedback Suggestion

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

microsoft/TypeScript#56091 · 2 comments · Opened Oct 12, 2023
async function drops `Awaited<Type>` Open

Needs Investigation

microsoft/TypeScript#56083 · 1 assignee · Opened Oct 12, 2023
Memory Leak / Infinite Recursion. TS hangs, TSC never finishes, VSCode and Intellisense dies. Open

Needs Investigation Rescheduled

microsoft/TypeScript#56081 · 9 comments · 17 reactions · 1 assignee · Opened Oct 12, 2023
Double slash comment `//` will be wrongly removed in the trailing position of the object attribute Open

Domain: Comment Emit Help Wanted Possible Improvement

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

microsoft/TypeScript#56055 · 2 comments · Opened Oct 10, 2023
`checkImportMetaProperty`: debug failure crash Open

Bug Domain: Crashes Help Wanted

Difficulty 3/5 1-2 days Newbie friendliness 35/100

microsoft/TypeScript#56054 · 4 comments · Opened Oct 10, 2023
Document how to use tsconfig-related APIs in the wiki Open

Docs

Difficulty 3/5 1-2 days Newbie friendliness 35/100

microsoft/TypeScript#56050 · 7 comments · Opened Oct 10, 2023
Having a `pedantic` option in TSConfig in addtion to `strict` Open

Awaiting More Feedback Suggestion

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

microsoft/TypeScript#56028 · 7 comments · 4 reactions · Opened Oct 8, 2023
regression in "key remapping breaks definition navigation" Open

Domain: LS: Symbol Navigation Experience Enhancement Help Wanted Suggestion

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

microsoft/TypeScript#56019 · 1 comment · 1 reaction · Opened Oct 7, 2023
Incorrect inference of mapped substitution type in conditional involving a union of arrays (regression) Open

Bug Domain: Conditional Types Help Wanted

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

microsoft/TypeScript#56018 · 1 comment · Opened Oct 7, 2023
Adding an overload to .filter breaks specific inference with nested functions Open

Bug Domain: check: Type Inference Help Wanted

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

microsoft/TypeScript#56013 · 2 reactions · Opened Oct 6, 2023
Mixin class with type param seems to lose information about default type parameter, causing "base constructors must all have the same return type" Open

Bug Domain: classes Help Wanted

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

microsoft/TypeScript#56005 · 4 reactions · Opened Oct 6, 2023
JS declaration emit invalid when typedefs present and `module.exports` is assigned a non-identifier Open

Bug Domain: Declaration Emit

microsoft/TypeScript#56002 · 1 reaction · 1 assignee · Opened Oct 5, 2023
Side effect of decorator Open

Bug Domain: Decorators Needs Investigation

microsoft/TypeScript#56000 · 9 comments · 1 assignee · Opened Oct 5, 2023
Update lib.dom.d.ts: `MutationObserverInit.attributeFilter` can accept an iterator Open

Bug Domain: lib.d.ts Help Wanted Needs Human Review

microsoft/TypeScript#55990 · 1 comment · 1 reaction · 2 assignees · Opened Oct 5, 2023
Allow base class expressions to reference class type parameters as long as the type param is not used on the static side of the resulting class Open

Awaiting More Feedback Suggestion

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

microsoft/TypeScript#55972 · 2 comments · 19 reactions · Opened Oct 3, 2023
Implementation signatures that do not contain all overloaded signatures are allowed in class definitions Open

Bug Domain: classes

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

microsoft/TypeScript#55963 · 1 comment · 1 reaction · Opened Oct 3, 2023
Performance regression from #49625 and #52984 Open

Bug Domain: Performance Rescheduled

microsoft/TypeScript#55948 · 23 comments · 3 reactions · 1 assignee · Opened Oct 2, 2023
tsserver plugin receives old proxy on configuration change Open

Docs

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

microsoft/TypeScript#55928 · 5 comments · Opened Sep 30, 2023
JSDoc `@overload`s on constructors don't capture class type parameters, can dictate their return type Open

checkJs Domain: JavaScript Domain: JSDoc Needs Investigation

microsoft/TypeScript#55919 · 7 comments · 1 reaction · 1 assignee · Opened Sep 29, 2023
`tsc` loses the class name in sourcemap Open

Domain: Source Maps Help Wanted Possible Improvement

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

microsoft/TypeScript#55912 · 4 reactions · Opened Sep 29, 2023
Keyword for inferring a new type from destructured parameters Open

Awaiting More Feedback Suggestion

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

microsoft/TypeScript#55908 · 9 comments · 8 reactions · Opened Sep 29, 2023
unique symbol lost on assignment to const despite type assertion Open

In Discussion Suggestion

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

microsoft/TypeScript#55901 · 7 comments · 4 reactions · Opened Sep 28, 2023
Indexing/element access on `super` avoids instance property checks Open

Bug Domain: classes Effort: Casual Help Wanted Rescheduled

microsoft/TypeScript#55899 · 1 comment · 1 assignee · Opened Sep 28, 2023
Outline doesn't include JS namespace object Open

Awaiting More Feedback Suggestion

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

microsoft/TypeScript#55896 · 3 comments · Opened Sep 27, 2023
SARIF output for tsc failures Open

Awaiting More Feedback Suggestion

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

microsoft/TypeScript#55890 · 5 comments · 6 reactions · Opened Sep 27, 2023
Container builds fails after upgrade to Microsoft.TypeScript.MSBuild 5.2.2 Open

Needs Investigation

microsoft/TypeScript#55886 · 3 comments · 1 assignee · Opened Sep 27, 2023
Misleading error message for `super.instanceProperty` Open

Bug Domain: Error Messages Rescheduled

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

microsoft/TypeScript#55883 · 6 comments · 7 reactions · Opened Sep 26, 2023
Provide an option to enable stricter type checking of Number.isNaN, Number.isFinite, etc. to catch very obvious bugs Open

Awaiting More Feedback Suggestion

Difficulty 5/5 Over a week Newbie friendliness 32/100

microsoft/TypeScript#55878 · 3 comments · 1 reaction · Opened Sep 26, 2023
TS Confuses namespace with the class on JSDoc module.exported class with static method. Open

Bug Domain: JSDoc Help Wanted

microsoft/TypeScript#55875 · 1 comment · 4 reactions · 1 assignee · Opened Sep 26, 2023
String#matchAll is too restrictive in its parameter type Open

Awaiting More Feedback Suggestion

Difficulty 3/5 1-2 days Newbie friendliness 43/100

microsoft/TypeScript#55843 · 1 comment · 1 reaction · Opened Sep 23, 2023
`never` as keyof tuples/arrays behaves the same as `number` Open

Domain: Indexed Access Types Possible Improvement

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

microsoft/TypeScript#55841 · 4 comments · Opened Sep 23, 2023
Generated d.ts includes implicit any for recursive types Open

Domain: Declaration Emit Help Wanted Possible Improvement

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

microsoft/TypeScript#55832 · 9 comments · Opened Sep 22, 2023
`--showConfig` doesn't resolve `paths` Open

Bug Domain: Module Resolution Help Wanted

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

microsoft/TypeScript#55825 · 2 reactions · Opened Sep 22, 2023
Support `!==` operator in `is` and `asserts` return type syntax Open

Awaiting More Feedback Suggestion

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

microsoft/TypeScript#55813 · 3 comments · 1 reaction · Opened Sep 21, 2023
ts2365 allows unsafe comparisons: string | number < string | number Open

Awaiting More Feedback Suggestion

Difficulty 5/5 Over a week Newbie friendliness 38/100

microsoft/TypeScript#55808 · 6 comments · Opened Sep 21, 2023
How to jump to the definition of a template string type in VSCode? Open

Domain: LS: Symbol Navigation Experience Enhancement Help Wanted Suggestion

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

microsoft/TypeScript#55819 · Opened Sep 21, 2023
Disallow newline after `as` after function instantiation Open

Domain: Parser Possible Improvement

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

microsoft/TypeScript#55806 · 6 comments · 4 reactions · Opened Sep 21, 2023
Mirror cursor for JSX stops working in some case Open

Bug Domain: JSX/TSX Help Wanted Needs Human Review

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

microsoft/TypeScript#56669 · 3 comments · 1 reaction · Opened Sep 20, 2023
Respect vscode recommendations for Go To Symbol feature Open

Experience Enhancement Help Wanted Suggestion

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

microsoft/TypeScript#56612 · 8 comments · Opened Sep 20, 2023

microsoft/TypeScript

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