`./*.d.ts` required in `exports` to avoid `Cannot be named without a reference to... not portable...`

🔎 Search Terms

The inferred type of '...' cannot be named without a reference to... This is likely not portable. A type annotation is necessary.

🕗 Version & Regression Information

Between 5.3 to 5.7 (latest)

⏯ Playground Link

No response

💻 Code

TSconfig of importing project

{
  "compilerOptions": {
    "outDir": "./lib",
    "rootDir": "./src",
    "tsBuildInfoFile": "./lib/.tsbuildinfo",

    "target": "ESNext",
    "module":"ESNext",
    "moduleResolution":"bundler",

    "composite": true,
    "declarationMap": true,
    "sourceMap": true,
    "strict": true,
    "esModuleInterop": true,
    "forceConsistentCasingInFileNames": true,
    "noErrorTruncation": true,
    "verbatimModuleSyntax": true,

    "emitDeclarationOnly": true,
    "skipLibCheck": true,

    "allowJs": true,

    
  },
  "include": ["src/**/*"]
}

Package.json of project BEING IMPORTED

{

  "type": "module",
  "files": [
    "lib/**/*",
    "src/**/*"
  ],
  "exports": {
    "./lib/*.d.ts": "./lib/*.d.ts",
    ".": {
      "types":"./lib/index.d.ts",
      "import":"./lib/index.js"
    }
  },
}

🙁 Actual behavior

If you do not include "./lib/*.d.ts": "./lib/*.d.ts" in the package.json of the imported project, you will receive the ...likely not portable... error.

However, in none of the documentations and searches I've seen was this written as a requirement. As a result, I assume it's a bug.

The problem with the above solution is that it exposes the .d.ts files, which causes intellisense import suggestions to suggest two imports (one from the proper path, and one from the .d.ts path).

Note:

1. The import is a direct dependency, not a transitive dependency.
2. Using main:./lib/index.js instead of exports:... also removes the error.

🙂 Expected behavior

Should not need to explicitly export all types

Additional information about the issue

No response