Question

I’m using the jQuery is() function from here. The documentation says that it returns a bool. In the TypeScript definition file it has the following for the is() function:

is(selector: string): JQuery;
is(func: (index: any) =>any): JQuery;
is(element: any): JQuery;
is(obj: JQuery): JQuery;

Am I correct in saying that I just need to change the return type from JQuery to bool to fix this in the definition file?

Answer 1

The is documentation seems pretty clear that this is the case.

Check the current matched set of elements against a selector, element,
or jQuery object and return true if at least one of these elements
matches the given arguments.

I’m not going to try and second guess the developer that wrote the jquery.d.ts definition – it is possible that there is a mistake in the jQuery documentation (it isn’t unknown) – but it is also likely that any jQuery functions that return things other than JQuery will have been mistakenly defined that way because most jQuery function do return a jQuery object.

I would change the return value to bool. I will raise a bug on Codeplex, that way the TypeScript team can either fix it or explain it.