Where is the syntax for TypeScript comments documented?

Question

Is the syntax for TypeScript comments documented anywhere?

And by any chance, does it now support the C# /// system?

Answer 1

Future

The TypeScript team, and other TypeScript involved teams, plan to create a standard formal TSDoc specification. The 1.0.0 draft hasn't been finalised yet: https://github.com/Microsoft/tsdoc#where-are-we-on-the-roadmap

Current

TypeScript uses JSDoc. e.g.

/** This is a description of the foo function. */
function foo() {
}

To learn jsdoc : https://jsdoc.app/

But you don't need to use the type annotation extensions in JSDoc.

You can (and should) still use other jsdoc block tags like @returns etc.

Example

Just an example. Focus on the types (not the content).

JSDoc version (notice types in docs):

/**
 * Returns the sum of a and b
 * @param {number} a
 * @param {number} b
 * @returns {number}
 */
function sum(a, b) {
    return a + b;
}

TypeScript version (notice the re-location of types):

/**
 * Takes two numbers and returns their sum
 * @param a first input to sum
 * @param b second input to sum
 * @returns sum of a and b
 */
function sum(a: number, b: number): number {
    return a + b;
}