JSDoc optional/required variant doesn't play well with multi-@param RecordType declarations

TypeScript Version: 2.9.0-dev.20180330

Search Terms: as mentioned in this comment, I'm opening this issue because with this JSDoc syntax typescript doesn't recognize the params correctly.

Code

// A *self-contained* demonstration of the problem follows...
// Test this by running `tsc` on the command-line, rather than through another build tool such as Gulp, Webpack, etc.

/**
 * @param {!object} args 
 * @param {!string} args.prop1
 * @param {?string} args.prop2
 */
function patate(args) {
  const { prop1, prop2 } = args;
} 

Expected behavior: No errors

Actual behavior: With allowJs and checkJs, I get JSDoc '@param' tag has name 'prop1', but is no parameter with that name.

Playground Link:

Related Issues: https://github.com/Microsoft/TypeScript/issues/19645

Issue にある自己完結型の JavaScript 例から始め、allowJs と checkJs を有効にして tsc を実行します。コンパイラが複数の @param を含む JSDoc 宣言をどのように処理するかを調査します。完了条件は、その例が args.prop1 または args.prop2 に対する診断を生成しないことです。