12 Pull requests merged by 10 people

• Issue "'{0}' declarations can only be declared inside a block." for block-scoped variables in presence of parse errors

  #61824 merged Jun 6, 2025

• explicitly disallow using in ambient contexts

  #61781 merged Jun 6, 2025

• Add lib.esnext.sharedmemory

  #61646 merged Jun 6, 2025

• Cache mapper instantiations

  #61505 merged Jun 6, 2025

• feat: add Error.isError() to ESNext lib

  #60788 merged Jun 6, 2025

• Add support for import defer proposal

  #60757 merged Jun 6, 2025

• tsc --init update

  #61813 merged Jun 6, 2025

• fix(checker): report error when using bigint as enum key

  #61777 merged Jun 5, 2025

• fix(61747): for (using of = is incorrectly parsed

  #61764 merged Jun 5, 2025

• LEGO: Pull request from lego/hb_5378966c-b857-470a-8675-daebef4a6da1_20250604192236101 to main

  #61815 merged Jun 4, 2025

• Initialize the map for dts to reference and source to reference when parsing project reference as its always needed

  #61746 merged Jun 4, 2025

• Update pr_owners.txt

  #61798 merged Jun 3, 2025

11 Pull requests opened by 8 people

• Fixed control flow Analysis of aliased discriminants with parenthesized initializers

  #61788 opened May 31, 2025

• Assign contextual parameter types to functions with type parameters

  #61792 opened Jun 1, 2025

• Fix capitalisation for `checkJs`

  #61795 opened Jun 1, 2025

• fix: const declarations inside block to be more aggressive

  #61796 opened Jun 1, 2025

• Bump the github-actions group across 1 directory with 3 updates

  #61804 opened Jun 2, 2025

• Add `--module node20`

  #61805 opened Jun 2, 2025

• Add check for unknown type

  #61810 opened Jun 4, 2025

• Fix helpers emit for .cjs files in ESM module mode

  #61814 opened Jun 4, 2025

• lib: narrow `Atomics.wait*` target to SharedArrayBuffer views

  #61817 opened Jun 4, 2025

• optimization, reduce memory usage

  #61822 opened Jun 6, 2025

• Fixed JSDoc display on `JsxNamespacedName` attributes

  #61825 opened Jun 6, 2025

21 Issues closed by 8 people

• "'const' declarations can only be declared inside a block" should be issued more aggressively

  #61734 closed Jun 6, 2025

• `declare namespace { using ... }` generates incorrect dts

  #61752 closed Jun 6, 2025

• Add Error.isError() to ESNext lib

  #60787 closed Jun 6, 2025

• `import defer` Stage 3 proposal support

  #59391 closed Jun 6, 2025

• tsc --init update 2024

  #58420 closed Jun 6, 2025

• Make the `sourceFile.commentDirectives` property public

  #61809 closed Jun 6, 2025

• ts plugin provide color

  #61773 closed Jun 6, 2025

• noUnusedLocals doesn't error when using a ...rest declaration

  #61748 closed Jun 6, 2025

• `someBool || true` gets the literal type `true` when assigned to a `let` variable at initialization (unlike `true` getting the type `boolean`)

  #61799 closed Jun 6, 2025

• Declaration Order Affects Type Checking

  #61806 closed Jun 6, 2025

• enum member key should reject bigint

  #61772 closed Jun 5, 2025

• `for (using of =` is incorrectly parsed.

  #61747 closed Jun 5, 2025

• Critical null pointer bug in incremental builder: affectedFilesIndex undefined access

  #61808 closed Jun 3, 2025

• [NewErrors] 5.9.0-dev.20250601 vs 5.8.3

  #61800 closed Jun 3, 2025

• [ServerErrors][TypeScript] 5.9.0-dev.20250601 vs 5.8.3

  #61803 closed Jun 3, 2025

• [ServerErrors][JavaScript] 5.9.0-dev.20250601 vs 5.8.3

  #61802 closed Jun 3, 2025

• [ServerErrors][TypeScript] 5.9.0-dev.20250525 vs 5.8.3

  #61765 closed Jun 3, 2025

• [ServerErrors][JavaScript] 5.9.0-dev.20250525 vs 5.8.3

  #61763 closed Jun 3, 2025

• [NewErrors] 5.9.0-dev.20250525 vs 5.8.3

  #61762 closed Jun 3, 2025

• Reference issue for PR #61796: Make const declarations inside block more aggressive

  #61797 closed Jun 1, 2025

• Deprecate `appendChild` in favor of `append`

  #61778 closed May 31, 2025

13 Issues opened by 13 people

• lib.dom.d.ts: AudioContextState enum is missing "interrupted" state

  #61823 opened Jun 6, 2025

• Functions unnecessarily wrapped into lambda functions

  #61821 opened Jun 6, 2025

• JSX `JsxNamespacedName` breaks JSDoc + QuickInfo in VSCode

  #61820 opened Jun 6, 2025

• Pipe Operator instead of conditions and deep extends

  #61819 opened Jun 5, 2025

• Overloads for String.prototype.split method

  #61816 opened Jun 4, 2025

• Misleading error for a generic parameter with a default involving `this`

  #61812 opened Jun 4, 2025

• renamedDependencies not working with ESM

  #61811 opened Jun 4, 2025

• Incorrect capitalisation for `checkJs`

  #61801 opened Jun 1, 2025

• `tsBuildInfoFile` is not extendable. Add an alternative `tsBuildInfoDir` option

  #61794 opened Jun 1, 2025

• Cannot assign Uint8Array type to Uint8Array variable created with constructor

  #61793 opened Jun 1, 2025

• Parameters in functions with type parameters are not contextually-typed

  #61791 opened Jun 1, 2025

• Please always add default values to `tsconfig.json` documentation

  #61790 opened Jun 1, 2025

• Skip assignment narrowing when declaring & initializing a variable in the same statement

  #61789 opened May 31, 2025

72 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.

• Reuse single errored signature candidate as resolved signature

  #61787 commented on Jun 6, 2025 • 4 new comments

• Add type definitions for `Uint8Array` to/from base64 methods

  #61696 commented on Jun 5, 2025 • 3 new comments

• Fixed an issue with `ReduceLabel` flows spoiling node reachability cache

  #61265 commented on Jun 6, 2025 • 1 new comment

• Suggest completions for type arguments of expressions

  #61758 commented on Jun 2, 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 Jun 6, 2025 • 0 new comments

• Compile error if I named last array destructuring element.

  #41548 commented on Jun 6, 2025 • 0 new comments

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

  #39650 commented on Jun 6, 2025 • 0 new comments

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

  #39114 commented on Jun 6, 2025 • 0 new comments

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

  #38388 commented on Jun 6, 2025 • 0 new comments

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

  #33471 commented on Jun 6, 2025 • 0 new comments

• Allow extending types referenced through interfaces

  #31843 commented on Jun 6, 2025 • 0 new comments

• Suggestion: Type annotations and interfaces for function declarations

  #22063 commented on Jun 6, 2025 • 0 new comments

• this any typed in some JS object literals

  #22058 commented on Jun 6, 2025 • 0 new comments

• Error inferring types of promise function

  #17873 commented on Jun 6, 2025 • 0 new comments

• Support @class in JSDoc

  #12681 commented on Jun 6, 2025 • 0 new comments

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

  #11920 commented on Jun 6, 2025 • 0 new comments

• Improve string split return type of first array index

  #53362 commented on Jun 6, 2025 • 0 new comments

• [BUG] This JSX tag requires the module path 'react/jsx-runtime' to exist, but none could be found. Make sure you have types for the appropriate package installed.

  #61756 commented on Jun 5, 2025 • 0 new comments

• ReturnType is lost after a simple wrapper function

  #61780 commented on Jun 5, 2025 • 0 new comments

• Spreading constrained generic parameters allows for invalid/unsafe return types

  #61754 commented on Jun 5, 2025 • 0 new comments

• Fix type variable leaks and cache inconsistencies

  #61668 commented on Jun 6, 2025 • 0 new comments

• Avoid resolving source prop type when the target is `unknown`/`any`

  #61660 commented on Jun 6, 2025 • 0 new comments

• Array method definition revamp: Use case collection

  #36554 commented on Jun 6, 2025 • 0 new comments

• Inconsistent typechecking with require() in JS and TS

  #60032 commented on Jun 6, 2025 • 0 new comments

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

  #57564 commented on Jun 6, 2025 • 0 new comments

• Inconsistent type inference on overloaded function types

  #57351 commented on Jun 6, 2025 • 0 new comments

• mapped type with remapped keys unexpectedly widens type

  #57265 commented on Jun 6, 2025 • 0 new comments

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

  #57009 commented on Jun 6, 2025 • 0 new comments

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

  #53234 commented on Jun 6, 2025 • 0 new comments

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

  #52313 commented on Jun 6, 2025 • 0 new comments

• Regression in 4.8 where string union type widens to string

  #50635 commented on Jun 6, 2025 • 0 new comments

• Intersection causes incorrect type compatability

  #48720 commented on Jun 6, 2025 • 0 new comments

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

  #46791 commented on Jun 6, 2025 • 0 new comments

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

  #43943 commented on Jun 6, 2025 • 0 new comments

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

  #42905 commented on Jun 6, 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 Jun 6, 2025 • 0 new comments

• not tracking potential state change in object literal with literal type property

  #61761 commented on Jun 4, 2025 • 0 new comments

• support control flow analysis of tagged template calls

  #51426 commented on Jun 4, 2025 • 0 new comments

• TS 5.8 TypeError: Cannot read properties of undefined (reading 'kind')

  #61351 commented on Jun 4, 2025 • 0 new comments

• MSBuild integration with ASP.NET Core

  #60538 commented on Jun 4, 2025 • 0 new comments

• 'in' does not remove undefined from indexed value (with noUncheckedIndexedAccess)

  #61389 commented on Jun 3, 2025 • 0 new comments

• Disallow bitwise operators with different const enum types

  #61760 commented on Jun 3, 2025 • 0 new comments

• [DTS] Object literal method with bigint is omitted in generated `.d.ts`, but class method works correctly

  #61769 commented on Jun 3, 2025 • 0 new comments

• TypeScript support for .mdx file extensions

  #36440 commented on Jun 3, 2025 • 0 new comments

• refactor: New file generates import from wrong module specifier

  #58897 commented on Jun 2, 2025 • 0 new comments

• Make default JSX mode "react"

  #8529 commented on Jun 2, 2025 • 0 new comments

• Function implementation name must be ... (2389) when abstract method is declared again later

  #61783 commented on Jun 2, 2025 • 0 new comments

• Variant accessors for index signatures and mapped types

  #43826 commented on Jun 1, 2025 • 0 new comments

• Generic template literal index does not resolve value type

  #50030 commented on Jun 1, 2025 • 0 new comments

• Proposal: JSX.ElementType

  #13890 commented on May 31, 2025 • 0 new comments

• Support a @nonnull/@nonnullable JSDoc assertion comment

  #23405 commented on May 31, 2025 • 0 new comments

• No semantic token assigned to import names, but available for export

  #57082 commented on May 31, 2025 • 0 new comments

• Allow type narrowing to be specified as always-on or always-off

  #57725 commented on May 31, 2025 • 0 new comments

• Support opting-out of type narrowing on assignment

  #49669 commented on May 31, 2025 • 0 new comments

• Reference missing with declare module

  #61766 commented on Jun 5, 2025 • 0 new comments

• Parenthesis break narrowing.

  #61784 commented on Jun 5, 2025 • 0 new comments

• Completions for type arguments of expressions

  #61751 commented on Jun 5, 2025 • 0 new comments

• Intersection of `object` and array breaks homomorphism

  #61745 commented on Jun 5, 2025 • 0 new comments

• Generic TypedArray constructors have only one overload

  #61680 commented on Jun 5, 2025 • 0 new comments

• Switch-like statement to avoid repetitive 'extends' ternary

  #51375 commented on Jun 5, 2025 • 0 new comments

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

  #61750 commented on Jun 5, 2025 • 0 new comments

• Add ES2025 target and library

  #61735 commented on Jun 5, 2025 • 0 new comments

• Format on paste deletes jsx comment content

  #61749 commented on Jun 5, 2025 • 0 new comments

• Prevent union of enums with same values (non-narrowable unions)

  #46085 commented on Jun 5, 2025 • 0 new comments

• Potentially misleading documentation for the `types` TSConfig option

  #61256 commented on Jun 5, 2025 • 0 new comments

• Error: Debug Failure. False expression.

  #52952 commented on Jun 4, 2025 • 0 new comments

• "Used before initialization" error false positives and negatives with optional properties

  #61785 commented on Jun 4, 2025 • 0 new comments

• [Feature Request] fieldof similar to keyof but include private and protected field

  #46802 commented on Jun 4, 2025 • 0 new comments

• Don't allow a `Record` keyed by a template literal type to be assigned to a type without a compatible index signature

  #61782 commented on Jun 4, 2025 • 0 new comments

• Intersection with a mapped type breaks bypassing private assignability.

  #61743 commented on Jun 4, 2025 • 0 new comments

• `IntegerTypedArray` type required for use with `crypto.getRandomValues`

  #61768 commented on Jun 4, 2025 • 0 new comments

• Missing references in TypeScript

  #61741 commented on Jun 4, 2025 • 0 new comments