[ts-5.5] Private aliases expanded in index and keyof types - 5.5 regression  #58713

🔎 Search Terms

type alias inlined regression 5.5

🕗 Version & Regression Information

• This changed between versions 5.5.0-dev.20240514 and 5.5.0-dev.20240515

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💻 Code

// @declaration: true

// @filename: a.ts
type O = {
    prop: string
    prop2: string
}

type I = {
    prop: string
}

export const fn = (v: O['prop'], o: Omit<O, keyof I>) => {};

// @filename: b.ts

import {fn} from './a'
export const f = fn;

🙁 Actual behavior

O['prop'] is written in declaration file as { prop: string; prop2: string; }[prop"]. And Omit<O, keyof I> is printed as Omit<{ prop: string; prop2: string; }, keyof { prop: string; }>

This is problematic especially if the type is a bigger as it balloon the size of the printed type and it may pull in references that were not previously used (causing new errors)

🙂 Expected behavior

O['prop'] is written in declaration file as string as O and Omit<O, keyof I> is printed as Omit<O, 'prop'> as in 5.4 since O and I can't be named

Additional information about the issue

No response