JSDoc optional property in object

TypeScript Version: 3.9.x & 4.1.x

Search Terms: jsdoc optional

There seems to be a regression since version 3.9.x where optional params in JSDocs are not converted correctly in declaration files. Several issues were created (linked below) and patches were made, however, it seems that params nested inside objects are still not correctly handled as optional when surrounded by brackets.

Code

/**
 * Does Foo
 *
 * @param {object} opts
 * @param {string} [opts.bar] - is optional
 * @returns void
 */
function foo(opts ) {
  // ..
}

Expected behavior: (as well as actual behavior <=3.8.3)

declare function foo(opts: {
    bar?: string;
}): void;

Actual behavior:

declare function foo(opts: {
    bar: string;
}): void;

Related Issues:
https://github.com/microsoft/TypeScript/issues/39111 was addressed with https://github.com/microsoft/TypeScript/pull/39487, but it doesn't seem that nested properties were covered in that fix.
https://github.com/microsoft/TypeScript/pull/39123 and https://github.com/microsoft/TypeScript/pull/39457 seem to relate to Closure notation, not sure if they're related.

Start by reproducing the provided JSDoc example with TypeScript 3.9.x and 4.1.x, comparing the emitted declaration with the expected optional nested property. Then read issue #39111 and pull request #39487 to understand the related fix; done means nested bracketed properties emit with ? in the declaration.