Generating documentation for Rollup.js projects using tools like JSDoc and TypeDoc

18 Sep 2023

Rollup.js is a popular JavaScript module bundler that allows you to create efficient and optimized bundles for your projects. When working on larger projects, it is essential to have comprehensive documentation to help developers understand and use your code effectively. In this blog post, we will explore two widely used tools, JSDoc and TypeDoc, that can assist in generating documentation for Rollup.js projects.

JSDoc

JSDoc is a documentation generator for JavaScript code. It allows you to annotate your code with special comments that describe the purpose and usage of your functions, classes, and variables. These comments can include tags like @param, @returns, and @example, providing valuable information to both developers and automated tools.

To start generating documentation with JSDoc, you need to follow these steps:

Install JSDoc globally by running the following command:
```
npm install -g jsdoc
```

Ensure that you have proper JSDoc comments in your code. For example:

/**
 * Calculates the sum of two numbers.
 * @param {number} a - The first number.
 * @param {number} b - The second number.
 * @returns {number} The sum of the two numbers.
 */
function add(a, b) {
  return a + b;
}

Generate the documentation by running the following command:
```
jsdoc path/to/your/code
```
This will create a new folder called out in the current directory, containing the generated HTML documentation files.
Open the index.html file in your browser to view the documentation.

JSDoc is a flexible and widely used tool for generating documentation. However, it focuses more on documenting the API contract and lacks support for generating documentation specifically for TypeScript projects. For TypeScript projects, an alternative tool called TypeDoc can be employed.

TypeDoc

TypeDoc is a documentation generator specifically designed for TypeScript projects. It extracts information from TypeScript type annotations and generates documentation that includes TypeScript-specific features like type information, interfaces, and modules.

To use TypeDoc for generating documentation in a Rollup.js TypeScript project, you can follow these steps:

Install TypeDoc globally by running the following command:
```
npm install -g typedoc
```

Ensure that you have TypeScript type annotations in your code. For example:

/**
 * Calculates the sum of two numbers.
 * @param {number} a - The first number.
 * @param {number} b - The second number.
 * @returns {number} The sum of the two numbers.
 */
function add(a: number, b: number): number {
  return a + b;
}

Generate the documentation by running the following command:
```
typedoc path/to/your/code
```
This will create a new folder called docs in the current directory, containing the generated HTML documentation files.
Open the index.html file in your browser to view the documentation.

TypeDoc provides a more TypeScript-centric approach to generating documentation, allowing you to leverage powerful TypeScript features to document your code.

Conclusion

Documentation is crucial for maintaining and sharing projects, and tools like JSDoc and TypeDoc make it easier to generate comprehensive documentation for Rollup.js projects. JSDoc is a versatile tool for generating documentation for JavaScript code, while TypeDoc is specifically designed for TypeScript. By annotating your code with these tools, you can ensure that your projects are well-documented and easier to understand for both yourself and other developers.

#documentation #rollupjs #jsdoc #typedoc