Support Object.<type1, type2> JSDoc notation for index signatures

[mjbvz]

From: microsoft/vscode#24291
TypeScript Version: 2.2.2

Code

/**
 * Test.
 *
 * @param {Object.<string, number>} obj An object.
 */
function func(obj) {
	console.log(obj);
}

Expected behavior:

obj has a type of Object<string, number> (at at least some equivalent type with an index signature). This syntax is valid according to http://usejsdoc.org/tags-type.html

Actual behavior:
obj has an any type

[yuit]

I think {object} and {Object} both should be object type and only object type is assignable to it. Because it is any at the moment, all kind of stuffs are allowed

[sandersn]

Fix is up at #17254

[michaeljota]

Should the fix work with object.<string, T> annotations or just with capitalized Object.<string, T>?

I ask because it does not seems to work with the former.

[sandersn]

The code currently only checks for Object, not object. But note that we treat Object as different from object in Javascript already: Object is a synonym for any, but object means "anything that's not number/boolean/string/null/undefined".

Feel free to open an issue and we can decide what the correct behaviour should be.

[michaeljota]

I understand that when is being used as a JSDoc annotation, object and Object should be treated as the same, but I may be wrong. I will try to post another issues with similarities on this.

[sandersn]

Yep, the current behaviour may be wrong because it is largely inherited from Typescript. A new issue to discuss it would be helpful so we can examine all the issues.

[michaeljota]

Done. 👍 Thanks you.