JSDoc-typed node modules require special configuration in consumers to be useful

It looks like an ongoing goal for TS is to recommend JSDoc as the recommended way to give type-checking to raw JS users. As a user I am not a huge fan of this approach but I'll try to be objective in this issue.

If I write a node module js-lib as raw javascript typed with jsdoc, it will appear as untyped to consumers of my module unless they specifically opt in to JS type checking.

Example:

+-js-lib
| +-index.js
| +-package.json
|
+-ts-consumer
  +-index.ts
  +-package.json
  +-tsconfig.json

js-lib/index.js

/**
 * @param {string} s
 * @returns {number}
 */
module.exports = function test(s) { return parseInt(s) };

js-lib/package.json

{
  "name": "js-lib",
  "main": "index.js"
}

ts-consumer/index.ts

import test = require('../js-lib');
// index.ts(1,23): error TS6143: Module '../js-lib' was resolved to '/Users/jarrad/src/personal/ts-test/lib/js-index.js', but '--allowJs' is not set.

import test = require('js-lib'); // after npm install ../js-lib
// index.ts(1,23): error TS7016: Could not find a declaration file for module 'lib'. '/Users/jarrad/src/personal/ts-test/lib/index.js' implicitly has an 'any' type.
//  Try `npm install @types/lib` if it exists or add a new declaration (.d.ts) file containing `declare module 'lib';

test("test");

ts-consumer/tsconfig.json

{
  "compilerOptions": {
    "strict": true
  }
}

It should be possible for me to make my js-lib usable to Typescript authors without them having to configure their own project with allowJs and checkJs.

例の js-lib/index.js、js-lib/package.json、ts-consumer/index.ts、ts-consumer/tsconfig.json を使って問題を再現します。まず、コンパイラが JavaScript Node モジュールをどのように解決し、TypeScript のコンシューマー向けの型情報をどのように見つけるかを追跡します。コンシューマーが allowJs と checkJs を有効にしなくても、JSDoc で型付けされたモジュールが有用な型を提供できれば完了です。