How to specify resolution and rejection type of the promise in JSDoc?
documentation, javascript, jsdoc, node.js, promise
Solution
Even if they don't exist in Javascript, I found that JSdoc understands "generic types".
So you can define your custom types and then use `/* @return Promise<MyType> */`. The following result in a nice TokenConsume(token) → {Promise.<Token>} with a link to your custom `Token` type in the doc.
/**
* @typedef Token
* @property {bool} valid True if the token is valid.
* @property {string} id The user id bound to the token.
*/
/**
* Consume a token
* @param {string} token [description]
* @return {Promise<Token>} A promise to the token.
*/
TokenConsume = function (string) {
// bla bla
}
It even works with `/* @return Promise<MyType|Error> */` or `/* @return Promise<MyType, Error> */`.
Problem
I have some code that returns a promise object, e.g. using Q library for NodeJS. ``` var Q = require('q'); /** * @returns ??? */ function task(err) { return err? Q.reject(new Error('Some error')) : Q.resolve('Some result'); } ``` How to document such a return value using JSDoc?