Revert "Always substitute indexed generic mapped type when getting constraint from indexed access" #57202
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…nstraint from indexed access (microsoft#53066)" This reverts commit abb4052.
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| @@ -14230,7 +14230,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker { | |||
| } | |||
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| function getConstraintFromIndexedAccess(type: IndexedAccessType) { | |||
| if (isMappedTypeGenericIndexedAccess(type) || isGenericMappedType(type.objectType)) { | |||
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while my comment here can be partially true - so far I couldn't find the situation in which this extra check would benefit anything (after adjustments) since getSimplifiedIndexedAccessType already performs this substitution when it's safe to do so
| @@ -57,5 +83,5 @@ type ObjectWithUnderscoredKeys<K extends string> = { | |||
| }; | |||
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| function genericTest<K extends string>(objectWithUnderscoredKeys: ObjectWithUnderscoredKeys<K>, key: K) { | |||
| const shouldBeTrue: true = objectWithUnderscoredKeys[`_${key}`]; | |||
| const shouldBeTrue: true = objectWithUnderscoredKeys[`_${key}`]; // assignability fails here, but ideally should not | |||
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Those kinds of cases could always be OK if we could determine that the template type doesn't depend on the original K. I don't think the compiler is equipped to check this sort of thing right now though.
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@DanielRosenwasser I don't think this revert needs to be cherry-picked or anything, right? Since we'll sync the release branch with |
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Yeah, it'll be in the RC |
reverts my own #53066 , fixes #53066 (comment)
cc @ahejlsberg @weswigham