Simplify indexed access types applied to mapped types #28965
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weswigham
reviewed
Dec 11, 2018
weswigham
reviewed
Dec 12, 2018
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| function f31<T, K extends keyof T>() { | ||
| let x: Partial<Partial<Partial<Partial<Partial<Partial<Partial<Record<keyof T, string>>>>>>>>[K] = "hello"; |
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Aside: Part of me wonders if we should have come rule in place to compact mapped types like this, even when generic.
weswigham
approved these changes
Dec 12, 2018
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Previously we didn't simplify indexed access types applied to mapped types beyond one level because it could cause infinite recursion when mapped types circularly reference themselves. With this PR we now simplify to any number of levels, meaning that constructs such as the following are no longer errors:
Fixes #28839.