Types declared in types.d.ts not included in output of tsc --emitDeclarationOnly

Bug Report

🔎 Search Terms

emitDeclarationOnly allowJs “missing types” “.d.ts file” “declaration file”

🕗 Version & Regression Information

When did you start seeing this bug occur?

Only noticed it just now.

• This is the behavior in every version I tried (typescript@latest, typescript@next, typescript@4.6), and I reviewed the FAQ for entries about declaration files

⏯ Playground Link

Workbench Repro

💻 Code

// index.js
function bar () {
  return 'baz';
}

/** @returns {BarFn} */
export function foo () {
  return bar;
}

// types.d.ts
type BarFn = () => string;

// jsconfig.json
{
  "compilerOptions": {
    "target": "es2021",
    "module": "es2022",
    "checkJs": true,
    "moduleResolution": "node",
    "strictNullChecks": true
  },
  "include": [
    "index.js",
    "types.d.ts"
  ]
}

// package.json
{
  "name": "tsc-emitdeclarationonly-js",
  "type": "module",
  "main": "index.js",
  "types": "types/lib/index.d.ts",
  "scripts": {
    "gentypes": "tsc -p jsconfig.json --noEmit false --declaration --emitDeclarationOnly --outDir types"
  },
  "devDependencies": {
    "typescript": "^4.9.3"
  }
}

🙁 Actual behavior

The command tsc -p jsconfig.json --noEmit false --declaration --emitDeclarationOnly --outDir types generates this types/index.d.ts:

/** @returns {BarFn} */
export function foo(): BarFn;

which is missing the declaration of BarFn.

🙂 Expected behavior

I expected the BarFn declaration to be included in the generated types/index.d.ts:

/** @returns {BarFn} */
export function foo(): BarFn;
export type BarFn = () => string;

… as indeed it is if I move the declaration from types.d.ts into index.js, expressed in JSDoc form:

/** @typedef {() => string} BarFn */

… but I don’t want it there and in JSDoc form, I want it in a types.d.ts file (visible across my codebase) and in TypeScript form. And included in the generated types/index.d.ts.

[RyanCavanaugh]

If you had a .d.ts file which you consumed and you published it along with your package, and someone else did the same thing, then you’d have a conflict in the global scope.

In general if you’re hand-authoring something that’s local to your project, it should be in a .ts file, not a .d.ts file.

[typescript-bot]

👋 Hi, I’m the Repro bot. I can help narrow down and track compiler bugs across releases! This comment reflects the current state of this repro running against the nightly TypeScript.

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Comment by @gthb

:+1: Compiled

Historical Information

Version	Reproduction Outputs
4.5.2, 4.6.2, 4.7.2, 4.8.2, 4.9.3	:+1: Compiled

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