Assign contextual parameter types to functions with type parameters#61792
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Andarist wants to merge 5 commits intomicrosoft:mainfrom
Closed
Assign contextual parameter types to functions with type parameters#61792Andarist wants to merge 5 commits intomicrosoft:mainfrom
Andarist wants to merge 5 commits intomicrosoft:mainfrom
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Pull Request Overview
This PR enables contextual typing for function expressions that introduce type parameters and updates related tests and compiler logic to reflect this change.
- Updates fourslash tests to expect generic parameter
Tinstead ofany. - Adds new compiler tests covering contextual typing of generic functions and generators.
- Removes exclusions for functions with type parameters in context-sensitivity checks.
Reviewed Changes
Copilot reviewed 7 out of 7 changed files in this pull request and generated no comments.
| File | Description |
|---|---|
| tests/cases/fourslash/contextualTypingGenericFunction1.ts | Updated expected quickInfo for generic parameter contexts |
| tests/cases/compiler/contextualTypingGenericFunction2.ts | Added new tests for contextual typing of functions with type params |
| src/compiler/utilities.ts | Removed exclusion of type-parameterized functions from context checks |
| src/compiler/checker.ts | Removed type-parameter guard in return-expression context check |
Comments suppressed due to low confidence (2)
src/compiler/utilities.ts:10785
- Update the function-level comment to reflect that functions with type parameters are now considered context-sensitive. For example, document why the previous exclusion was removed and reference issue #61791.
export function hasContextSensitiveParameters(node: FunctionLikeDeclaration): boolean {
src/compiler/checker.ts:21027
- Add or update a comment explaining that functions with type parameters now participate in contextual return typing and why the
node.typeParameterscheck was removed.
function hasContextSensitiveReturnExpression(node: FunctionLikeDeclaration) {
…types-for-generic-functions
Andarist
commented
Jun 25, 2025
This reverts commit b97406f.
…empt to hoist inferred type parameters
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fixes #61791