auto-import with package.json#imports does not take moduleResolution into account

[alan910127]

🔎 Search Terms

"subpath", "imports", "package.json", "moduleResolution"

🕗 Version & Regression Information

• This changed in commit or PR Add auto-import for the package.json imports field #55015
• This is the behavior in every version I tried, and I reviewed the FAQ for entries about imports, completions

⏯ Playground Link

alan910127/ts-60405-repro

💻 Code

// package.json
{
  "imports": {
    "#*": "./src/*"
  },
  "devDependencies": {
    "typescript": "5.6.3"
  }
}

// tsconfig.json
{
  "compilerOptions": {
    "moduleResolution": "Bundler"
  }
}

// src/foo/bar/baz.ts
export function baz() {}

// src/one/two/three.ts
// actual   - import { baz } from "#foo/bar/baz.js";
// expected - import { baz } from "#foo/bar/baz";

🙁 Actual behavior

When auto-importing the function baz (either through completion or code action), the typescript language server will insert an import statement with a .js file extension.

import { baz } from "#foo/bar/baz.js";

🙂 Expected behavior

Since we are using "moduleResolution": "Bundler", it should insert an import statement without the .js file extension.

import { baz } from "#foo/bar/baz";

Additional information about the issue

I've seen a similar issue #59200, but I cannot reproduce the issue, with the same setup. Therefore, I think my issue might be related with the subpath imports.

[Andarist]

I don't think this is a bug. package.json#imports don't describe relative specifiers. Resolving #foo/bar/baz based on "#*": "./src/*" to ./src/foo/bar/baz.js would be incorrect.

A related comment to this by @andrewbranch :

#60003 (comment)

[alan910127]

Oh, I see. But TypeScript language server does not error if I use the extensionless module specifier either. Why is that the case?

[Andarist]

The thread I linked to specifically calls out extensionless module specifiers as erroring. If they are not then perhaps that is a bug - it might be good to wait for @andrewbranch to chime in. It would be good to understand the difference between that issue and yours.

[andrewbranch]

@alan910127 your repo link above 404s—did you accidentally make it private? If you share the repo, I’ll investigate. @Andarist is right; the import you listed as your expected behavior should have an error.