microsoft / microsoft/TypeScript

Attempt to more-frequently use local aliases when printing out types

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Domain: LS: Type Display Needs Proposal Suggestion
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Description

When a user imports a type alias like

// ./a.ts
export type Foo = number | string | symbol;

We should try to print out Foo in error messages like in

// ./b.ts
import { Foo } from "./a.js"

let x: Foo = true;

and in declaration emit like in


// ./c.ts
import { Foo } from "./a.js"

function f(x: Foo) {
  return x;
}

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  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Reproduce the examples in a.ts, b.ts, and c.ts, checking both the error message and declaration emit behavior. Trace the compiler's type-printing and declaration-emit entry points; done means imported local aliases such as Foo are used where appropriate in both outputs.

Written by the indexing model from the issue text.

Assessment

Tech stack
typescript
Domain
compilers
Issue type
Feature
Difficulty
5/5
Estimated time
Over a week
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
35/100

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