JSDoc types not supported

[johndeighan]

$ deno --version
deno 2.1.4 (stable, release, x86_64-pc-windows-msvc)
v8 13.0.245.12-rusty
typescript 5.6.2

JSDoc allows you to specify the type of parameters or the return value in JavaScript code like:

/**
 * Represents a book.
 * @param {string} title - The title of the book.
 * @param {string} author - The author of the book.
 * @returns {boolean}
 */
function Book(title, author) {
}

However, though Deno 2 claims to support both TypeScript and JavaScript development, it doesn't support this method of specifying types. To be more specific, when I include JSDoc like the above, the {string} and {boolean} strings are ignored and the documentation produced doesn't include the type of parameters or return values.

[dsherret]

Can you show a full reproduction (What does your file look like? What command are you running?)? Does that javascript file have // @ts-check at the top?

[johndeighan]

Since the input file is a JavaScript file, it definitely does not have // @ts-check anywhere in it. Here is a sample input file, which I've named book.js and placed in my src/lib folder:

/**
 * book - provides functions for use in unit tests
 *
 * @module
 */

/**
 * Represents a book
 *
 * @param {string} title
 * @param {string} author
 * @returns {boolean}
 */

export const book = (title, author) => {

	return true
}

Note that this is JSDoc's standard way of specifying types for parameters (see https://jsdoc.app/tags-param).

Next, I run deno doc --html src/lib/book.js (my project has the folder src/lib). This command creates a folder named docs, which contains a bunch of files, including an index.html. When I open that file with Chrome, I see this:

When I click on the word book, I see this:

Note that there is no type information associated with the parameters, and the return type is listed as "unknown", even though the type information is there in my JSDoc block.