How to Use Deno Doc: Generate Documentation for Your Code

Use the deno doc command followed by a file or module path to generate documentation from your code comments. It extracts JSDoc comments and shows a structured summary of functions, classes, and types in your code.

Syntax

The basic syntax of deno doc is:

• deno doc [options] <file_or_module>: Generates documentation for the specified file or module.
• --json: Outputs the documentation in JSON format.
• --private: Includes private members in the documentation.

You can also specify URLs or local file paths.

bash

deno doc [options] <file_or_module>

Example

This example shows how to generate documentation for a simple TypeScript file with JSDoc comments.

typescript

/**
 * Adds two numbers together.
 * @param a First number
 * @param b Second number
 * @returns The sum of a and b
 */
export function add(a: number, b: number): number {
  return a + b;
}

/**
 * A simple class representing a person.
 */
export class Person {
  /** The person's name */
  name: string;

  /**
   * Creates a new Person.
   * @param name The name of the person
   */
  constructor(name: string) {
    this.name = name;
  }
}

Example Usage and Output

Run the following command in your terminal to see the documentation summary:

bash

deno doc example.ts

Output

example.ts

export function add(a: number, b: number): number
  Adds two numbers together.

export class Person
  A simple class representing a person.

  name: string
    The person's name

  constructor(name: string)
    Creates a new Person.

Common Pitfalls

• Not using proper JSDoc comments (use /** ... */ or /// for documentation).
• Running deno doc without specifying a file or module will show an error.
• Private members are not shown unless you use the --private flag.
• Ensure your code compiles without errors; otherwise, deno doc may fail.

typescript

/* Wrong: Missing JSDoc style comment */
// Adds two numbers
export function add(a: number, b: number): number {
  return a + b;
}

/* Right: Proper JSDoc comment */
/**
 * Adds two numbers.
 * @param a First number
 * @param b Second number
 * @returns Sum of a and b
 */
export function add(a: number, b: number): number {
  return a + b;
}

Quick Reference

Here is a quick summary of useful deno doc options:

Option	Description
deno doc <file_or_module>	Generate documentation for a file or module.
--json	Output documentation in JSON format.
--private	Include private members in the output.
--unstable	Use unstable Deno APIs if needed.

Key Takeaways

Use deno doc <file_or_module> to generate documentation from your code comments.

Write clear JSDoc comments using /** ... */ or /// for best results.

Add --private to include private members in the documentation output.

You can output JSON format with --json for further processing.

Ensure your code compiles without errors before running deno doc.