dependency-cruiser

What is dependency-cruiser?

dependency-cruiser is a tool to analyze and visualize the dependencies in your JavaScript and TypeScript projects. It helps you understand the structure of your codebase, identify potential issues, and enforce architectural rules.

What are dependency-cruiser's main functionalities?

Dependency Graph Generation

Generates a dependency graph for the specified source directory. This helps in visualizing the dependencies between different modules in your project.

const depCruiser = require('dependency-cruiser');
const result = depCruiser.cruise(['src']);
console.log(result.output);

Enforcing Architectural Rules

Allows you to define and enforce architectural rules, such as preventing circular dependencies. This helps maintain a clean and manageable codebase.

const depCruiser = require('dependency-cruiser');
const config = {
  forbidden: [
    {
      name: 'no-circular',
      severity: 'error',
      comment: 'Circular dependencies are not allowed',
      from: {},
      to: {
        circular: true
      }
    }
  ]
};
const result = depCruiser.cruise(['src'], config);
console.log(result.output);

Reporting

Generates reports in various formats (e.g., JSON, HTML) to help you analyze the dependency structure and identify potential issues.

const depCruiser = require('dependency-cruiser');
const result = depCruiser.cruise(['src'], {}, { outputType: 'json' });
console.log(JSON.stringify(result.output, null, 2));

Other packages similar to dependency-cruiser

madge

Madge is a JavaScript library that visualizes the module dependency graph of your project. It can detect circular dependencies and generate visual graphs. Compared to dependency-cruiser, Madge is more focused on visualization and less on enforcing architectural rules.

depcheck

Depcheck is a tool that helps you find unused dependencies in your project. While it doesn't provide the same level of dependency graph visualization as dependency-cruiser, it is useful for cleaning up your package.json file by identifying dependencies that are no longer in use.

webpack-bundle-analyzer

Webpack Bundle Analyzer is a tool that visualizes the size of webpack output files with an interactive zoomable treemap. It is more focused on analyzing the size and composition of your webpack bundles rather than the dependency structure of your source code.

README

Dependency cruiser

Validate and visualise dependencies. With your rules. JavaScript. TypeScript. CoffeeScript. ES6, CommonJS, AMD.

What's this do?

This runs through the dependencies in any JavaScript, TypeScript, LiveScript or CoffeeScript project and ...

• ... validates them against (your own) rules
• ... reports violated rules
  • in text (for your builds)
  • in graphics (for your eyeballs)

As a side effect it can generate dependency graphs in various output formats including cool visualizations you can stick on the wall to impress your grandma.

How do I use it?

Install it ...

npm install --save-dev dependency-cruiser
# or
yarn add -D dependency-cruiser
pnpm add -D dependency-cruiser

... and generate a config

npx depcruise --init

This will look around in your environment a bit, ask you some questions and create a .dependency-cruiser.js configuration file attuned to your project¹².

Show stuff to your grandma

To create a graph of the dependencies in your src folder, you'd run dependency cruiser with output type dot and run GraphViz dot³ on the result. In a one liner:

npx depcruise src --include-only "^src" --config --output-type dot | dot -T svg > dependency-graph.svg

• You can read more about what you can do with --include-only and other command line options in the command line interface documentation.
• Real world samples contains dependency cruises of some of the most used projects on npm.
• If our grandma is more into formats like mermaid, json, csv, html or plain text we've got her covered as well.

Validate things

Declare some rules

When you ran the depcruise --init command above, the command also added some rules to .dependency-cruiser.js that make sense in most projects, like detecting circular dependencies, dependencies missing in package.json, orphans, and production code relying on dev- or optionalDependencies.

Start adding your own rules by tweaking that file.

Sample rule:

{
  "forbidden": [
    {
      "name": "not-to-test",
      "comment": "don't allow dependencies from outside the test folder to test",
      "severity": "error",
      "from": { "pathNot": "^test" },
      "to": { "path": "^test" }
    }
  ]
}

• To read more about writing rules check the writing rules tutorial or the rules reference

Report them

npx depcruise --config .dependency-cruiser.js src

This will validate against your rules and shows any violations in an eslint-like format:

There's more ways to report validations; in a graph (like the one on top of this readme) or in an self-containing html file.

• Read more about the err, dot, csv and html reporters in the command line interface documentation.
• dependency-cruiser uses itself to check on itself in its own build process; see the depcruise script in the package.json

I want to know more!

You've come to the right place :-) :

• Usage
  • Command line reference
  • Writing rules
  • Rules reference
  • Options reference
  • FAQ
• Hacking on dependency-cruiser
  • API
  • Output format
  • Adding other output formats
  • Adding support for other alt-js languages
• Other things
  • Road map
  • Contact
  • Real world show cases
  • TypeScript, CoffeeScript and LiveScript support
  • Support for .jsx, .tsx, .csx/ .cjsx, .vue and .svelte
  • Webpack alias/ modules support

License

MIT

Thanks

• Marijn Haverbeke and other people who collaborated on acorn - the excellent JavaScript parser dependency-cruiser uses to infer dependencies.
• Katerina Limpitsouni of unDraw for the ollie in dependency-cruiser's social media image.
• All members of the open source community who have been kind enough to raise issues, ask questions and make pull requests to get dependency-cruiser to be a better tool.

Build status

Made with :metal: in Holland.

Footnotes

1. We're using npx in the example scripts for convenience. When you use the commands in a script in package.json it's not necessary to prefix them with npx. ↩

2. If you don't don't want to use npx, but instead pnpx (from the pnpm package manager) or yarn - please refer to that tool's documentation. Particularly pnpx has semantics that differ from npx quite significantly and that you want to be aware of before using it. In the mean time: npx should work even when you installed the dependency with a package manager different from npm. ↩

3. This assumes the GraphViz dot command is available - on most linux and comparable systems this will be. In case it's not, see GraphViz' download page for instructions on how to get it on your machine. ↩