Automatically resolve custom path aliases in build

[lffg]

Search Terms

automatically resolve custom path aliases in build generated code

Suggestion

I personally can't find the reason why TypeScript does not automatically resolve custom path aliases in the build.

TypeScript is a compiler, so I think that it should take care of that.

To avoid any breaking changes, I think that introducing a new option such as resolveCustomPaths is a good solution.

Use Cases

When I have the paths option set in the tsconfig.json, TypeScript will automatically resolve the import paths in the generated code.

Examples

If I have the following tsconfig.json:

{
  "compilerOptions": {
    "baseUrl": "src",
    "paths": {
      "@core/*": ["app/core/*"]
      "@services/*": ["app/services/*"]
    }
  }
}

And I have the following /src/app/http/controllers/UserController.ts file:

import { ... } from '@services/my-service.ts';

Would be nice if the UserController.ts could be compiled into something like:

// UserController.js (Compiled)

// BaseURL (tsconfig.json `src`) + CustomPath (tsconfig.json `app/services`) + RequiredFile (`my-service.ts`)
const { ... } = require('src/app/services/my-service.js');

Checklist

My suggestion meets these guidelines:

• This wouldn't be a breaking change in existing TypeScript/JavaScript code
• This wouldn't change the runtime behavior of existing JavaScript code
• This could be implemented without emitting different JS based on the types of the expressions
• This isn't a runtime feature (e.g. library functionality, non-ECMAScript syntax with JavaScript output, etc.)
• This feature would agree with the rest of TypeScript's Design Goals.

[fatcerberus]

See #31643 (comment).