How to get VSCode to show my libraries function arguments when hovered

Question

I wrote a JavaScript library, and I'm trying to understand how I can show the function parameters/definitions when a user hovers over them in VSCode (I see this in other libraries, and I dont notice anything special about them). Im sure its something simple but I just dont see how I would do it. Link to the project is here: https://github.com/isaacgr/jaysonic

I've tried adding jsdoc style comments around the class definitions, but in general I'm not sure what to try. I'd appreciate if someone could point me in the right direction.

An example would be what I see with JSON.parse

Answer 1

Visual Studio Code uses IntelliSense for autocompletions like the one you mentioned and in JavaScript they are based mainly on TypeScript definitions. If a project is already built using TypeScript, they may be generated and linked in the corresponding package.json-file using a "typings" or "types" property.

Alternatively (I haven't tested this approach though) existing JSDoc comments may be used to generate these TypeScript Definitions.

The TypeScript Community has furthermore (often manually) created separate Typescript-Definitions, which are available as npm packages called @types/name-of-the-package.

In your case the first approach of creating/generating a typings-file and linking it in your package.json is probably the best approach to achieve the desired result.

Btw, if you want to inspect such a typescript definitions file, press Ctrl (on Windows) and click on the JSON.parse method. This will show you the corresponding typescript definitions file called lib.es5.d.ts (which is embedded in vscode as it's part of the JavaScript language and therefore doesn't need to be installed)