Jsdoc @template in scope as type parameter #16463
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The test to make sure that type parameters are in scope for instantiation previously ignored type parameters created by `@template`. Now it correctly says that they are in scope.
src/compiler/checker.ts
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| @@ -8168,8 +8166,9 @@ namespace ts { | |||
| case SyntaxKind.InterfaceDeclaration: | |||
| case SyntaxKind.TypeAliasDeclaration: | |||
| const declaration = node as DeclarationWithTypeParameters; | |||
| if (declaration.typeParameters) { | |||
| for (const d of declaration.typeParameters) { | |||
| const typeParameters = declaration.typeParameters || getTypeParametersFromJSDocTemplate(declaration); | |||
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@rbuckton has been using a pattern to use of getEffectiveType* to get the TS nodes, or the ones from JSDoc. we can follow the same here and use getEffectiveTypeParameters
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and use that in both places where you need the type parametes
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Thanks for pointing out that pattern. Done.
Create getEffectiveTypeParameterDeclarations in utilities.ts
src/compiler/utilities.ts
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| * Gets the effective return type annotation of a signature. If the node was parsed in a | ||
| * JavaScript file, gets the return type annotation from JSDoc. | ||
| */ | ||
| export function getEffectiveTypeParameterDeclarations(node: DeclarationWithTypeParameters): TypeParameterDeclaration[] { |
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do you see any perf impact of having this function here vs in checker.ts?
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Is there normally a perf impact for moving functions to utilities? I didn't expect anything. But I can check to see whether anything shows up.
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these are emitted to ts. instead of the direct function call.
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No, there is no perf impact. Monaco gets 0.05s slower, TFS gets 0.04s faster on average over 20 iterations. But neither number is statistically significant.
The code to make sure that type parameters are in scope for instantiation previously ignored type parameters created by
@template. Now it correctly says that they are in scope.Fixes #15177, which showed that functions returned from a generic function were not instantiated. Turns out this was because the type parameters were not recognised as in scope, so the instantiation algorithm skipped them.