1 Release published by 1 person

• v5.9.2 TypeScript 5.9

  published Jul 31, 2025

6 Pull requests merged by 5 people

• 🤖 Pick PR #61978 (Restructure CI to prepare for requi...) into release-5.9

  #62164 merged Aug 1, 2025

• Intentionally regress one buggy declaration output to an older version

  #62163 merged Aug 1, 2025

• Bump version to 6.0

  #62162 merged Jul 31, 2025

• Restructure CI to prepare for required checks and merge queues

  #61978 merged Jul 31, 2025

• Fix private identifier fields generating errors in class expression declarations

  #62155 merged Jul 31, 2025

• Add format to update baselines/fix lints task

  #62160 merged Jul 31, 2025

3 Pull requests opened by 3 people

• Revert PR 61668

  #62158 opened Jul 31, 2025

• Enhance type argument completions

  #62170 opened Aug 1, 2025

• Use tuple context based on apparent type of the contextual type uninstantiated by return mapper

  #62174 opened Aug 1, 2025

8 Issues closed by 5 people

• Typescript compiler removes comments it ought not remove

  #62159 closed Aug 3, 2025

• Type inference incorrectly considers `const z = { ...this }` to be `z: this`

  #62154 closed Aug 3, 2025

• TSC Compiler fails with Zod v3 and fails with Zod v4

  #62172 closed Aug 2, 2025

• Class member variable types incorrectly narrowed for constant assignments when calling member functions afterwards

  #62148 closed Aug 2, 2025

• minify when compile

  #62165 closed Aug 1, 2025

• TypeScript 5.9 is added under the latest tag, but should have been the RC tag?

  #62166 closed Aug 1, 2025

• regression: Private fields appear in type literal in declarations (5.9)

  #62153 closed Jul 31, 2025

• Arrow function needs extra declaration on asserts

  #62157 closed Jul 31, 2025

10 Issues opened by 6 people

• Infer-only function generics

  #62182 opened Aug 3, 2025

• Ghost error in a circular situation

  #62181 opened Aug 3, 2025

• Confusing missing property error in a circular situation

  #62180 opened Aug 3, 2025

• ImportType attributes can include JS expressions

  #62179 opened Aug 3, 2025

• Confusing in narrowing and property access on type parameter with `never` base constraint

  #62178 opened Aug 2, 2025

• Issues around casting tuples to arrays

  #62177 opened Aug 2, 2025

• No error on self-referencing type parameter of non-generic mapped type

  #62176 opened Aug 2, 2025

• type BufferSource has changed, causing my project to not pass

  #62168 opened Aug 1, 2025

• Inferred return type of functions in array allows incorrect value for optional property of return type

  #62167 opened Aug 1, 2025

• Bloomberg feedback for 5.9

  #62156 opened Jul 31, 2025

54 Unresolved conversations

Sometimes conversations happen on old items that aren’t yet closed. Here is a list of all the Issues and Pull Requests with unresolved conversations.

• Fix using transform variable shadowing in for-of loops

  #61934 commented on Aug 1, 2025 • 1 new comment

• Support Intellisense for string/number literals in a widened union

  #33471 commented on Aug 3, 2025 • 0 new comments

• Implicit Symbol.iterator call in for..of loops / spread destructuring doesn't infer `this` generic type parameter

  #38388 commented on Aug 3, 2025 • 0 new comments

• improper declared type cause narrow type not work when its computed type is not union.

  #39114 commented on Aug 3, 2025 • 0 new comments

• In JSDoc @type is not a type declaration, which it is much more like type conversion.

  #39650 commented on Aug 3, 2025 • 0 new comments

• Compile error if I named last array destructuring element.

  #41548 commented on Aug 3, 2025 • 0 new comments

• Error when trying to assign a subclass of a base class with generics to `typeof` of that base class

  #41770 commented on Aug 3, 2025 • 0 new comments

• Correctly handle generic functions (e.g.: `Object.freeze`) passed as callbacks to generic functions (e.g.: `Array.prototype.map`)

  #42862 commented on Aug 3, 2025 • 0 new comments

• Broken emit when `Infinity` or `‑Infinity` ends up in a type position

  #42905 commented on Aug 3, 2025 • 0 new comments

• Typescript 4.2.x - incorrectly infered generic return type of a record union (extra undefined)

  #43943 commented on Aug 3, 2025 • 0 new comments

• Support inferring `never` as the return type in JavaScript when overriding a class method that returns `never`

  #46791 commented on Aug 3, 2025 • 0 new comments

• Intersection causes incorrect type compatability

  #48720 commented on Aug 3, 2025 • 0 new comments

• Regression in 4.8 where string union type widens to string

  #50635 commented on Aug 3, 2025 • 0 new comments

• Order of ReadonlySet/ReadonlyMap in union causes differing key inference

  #52313 commented on Aug 3, 2025 • 0 new comments

• Expression produces a union type that is too complex to represent

  #53234 commented on Aug 3, 2025 • 0 new comments

• Crash when defining `Array` type via `[]` syntax

  #57009 commented on Aug 3, 2025 • 0 new comments

• mapped type with remapped keys unexpectedly widens type

  #57265 commented on Aug 3, 2025 • 0 new comments

• Inconsistent type inference on overloaded function types

  #57351 commented on Aug 3, 2025 • 0 new comments

• Error not issued when global type is an alias of an object type literal

  #57564 commented on Aug 3, 2025 • 0 new comments

• Inconsistent typechecking with require() in JS and TS

  #60032 commented on Aug 3, 2025 • 0 new comments

• Suggestion: a built-in TypedArray interface

  #15402 commented on Aug 3, 2025 • 0 new comments

• Add the type of Intl.DurationFormat to the lib.

  #60646 commented on Aug 2, 2025 • 0 new comments

• Fix debug assertion failure in move to file refactor for React components

  #62067 commented on Aug 2, 2025 • 0 new comments

• Implement enhanced CLI error formatting

  #62130 commented on Aug 2, 2025 • 0 new comments

• Add types for `RegExp.escape`

  #62138 commented on Aug 2, 2025 • 0 new comments

• Trimmed leading and trailing spaces when reading string literals after "[" and added a test case.

  #62144 commented on Aug 2, 2025 • 0 new comments

• LEGO: Pull request from lego/hb_5378966c-b857-470a-8675-daebef4a6da1_20250730202607176 to main

  #62150 commented on Aug 2, 2025 • 0 new comments

• ScriptKind.Deferred treated as LanguageVariant.Standard

  #60125 commented on Jul 31, 2025 • 0 new comments

• Add ES2025 target and library

  #61735 commented on Jul 31, 2025 • 0 new comments

• rewriteRelativeImportExtensions: tsc doesn't rewrite extensions in emitted declaration files

  #61037 commented on Jul 31, 2025 • 0 new comments

• TypeScript 5.9 Iteration Plan

  #61648 commented on Jul 31, 2025 • 0 new comments

• Double slash comment `//` will be wrongly removed in the trailing position of the object attribute

  #56055 commented on Jul 31, 2025 • 0 new comments

• Safe type assertion (upcast / widening) operator

  #56235 commented on Jul 31, 2025 • 0 new comments

• Proposal: repurpose "is" operator for a narrowing version of "satisfies"

  #62146 commented on Jul 31, 2025 • 0 new comments

• Support import types in JSDoc links

  #43950 commented on Aug 1, 2025 • 0 new comments

• Completions for type arguments of expressions

  #61751 commented on Aug 1, 2025 • 0 new comments

• Autocomplete on extends keyof generic

  #28662 commented on Aug 1, 2025 • 0 new comments

• respect pragma for imports on sort

  #62147 commented on Aug 1, 2025 • 0 new comments

• compiler memory leak in 5.8.x and upwards

  #62143 commented on Aug 1, 2025 • 0 new comments

• Commit characters are not reset inside typescript object property key strings

  #62161 commented on Aug 1, 2025 • 0 new comments

• Allow use of `infer` in the type parameter of a type declaration

  #52791 commented on Aug 1, 2025 • 0 new comments

• Custom JSDoc type cannot be extended

  #62021 commented on Aug 2, 2025 • 0 new comments

• 6.0 Deprecation Candidates

  #54500 commented on Aug 2, 2025 • 0 new comments

• Move to File and Move to new File not working to React components

  #62029 commented on Aug 2, 2025 • 0 new comments

• Autocompletion fails - unnecessarily narrow for inferred Generic

  #52726 commented on Aug 2, 2025 • 0 new comments

• Google feedback on TS 5.9-beta

  #62083 commented on Aug 2, 2025 • 0 new comments

• TypeScript: 3 connected together BUGS in `Refactor: move to file`

  #62022 commented on Aug 2, 2025 • 0 new comments

• Tuples: maintaining type-param in the type of it's items

  #61750 commented on Aug 3, 2025 • 0 new comments

• disallow comparing to null and undefined unless they are valid cases in strict null mode

  #11920 commented on Aug 3, 2025 • 0 new comments

• Support @class in JSDoc

  #12681 commented on Aug 3, 2025 • 0 new comments

• Error inferring types of promise function

  #17873 commented on Aug 3, 2025 • 0 new comments

• this any typed in some JS object literals

  #22058 commented on Aug 3, 2025 • 0 new comments

• Suggestion: Type annotations and interfaces for function declarations

  #22063 commented on Aug 3, 2025 • 0 new comments

• Allow extending types referenced through interfaces

  #31843 commented on Aug 3, 2025 • 0 new comments