depngn (short for dependency engine)

A CLI tool to find out if your dependencies support a given version of node. It fetches the engines field of your dependencies' package.json file and, if it's present, determines whether or not the version of node satisfies the range of supported versions.

CLI

Usage

npx depngn <node-version> [options]

# examples
npx depngn 10.0.0

npx depngn 14.17.6 --reporter=json

Node Version

depngn will accept any single value version of node as an argument (ie, not a range). If no version is given, it will attempt to determine your current node version and use that.

Options

depngn supports these options:

• --help
• --cwd
• --reporter
• --reportDir
• --reportFileName

--cwd

Specify the path where you want the check to be performed

--reporter

These are the valid values for --reporter:

• terminal (default): It will output a table to the terminal.
• html: It will generate an HTML file named compat.html to the directory the command is executed in.
• json: It will write a file named compat.json to the directory the command is executed in. It uses the following format:

[package_name]: {
  compatible: boolean // whether or not this package will work with the given Node version
  range: string // the range of supported Node versions
}

--reportDir

This allows you to specify the path where you want the report to be generated. If no path is specified, it will default to the current working directory.

--reportFileName

This allows you to specify the name of the report file. If no name is specified, it will default to compat.

A Note on The Engines Field

The engines field in package.json is optional and many libraries don't include it. If that's the case, the output for that package will be:

{
  compatible: undefined,
  range: 'n/a'
}

Standalone Package

You can also import depngn as a standalone function to use in your own CLI tools. It takes an object as an argument:

interface Options {
  version: string;
  cwd: string | undefined;
}

And it returns a promise that resolves to:

type DepngnReturn = Record<string, CompatData>;

interface CompatData {
  compatible: boolean | 'invalid' | undefined;
  range: string;
}

Usage

import { depngn } from 'depngn';

const generateReport = async () => {
  return await depngn({ version: '10.0.0' });
};

There's also a chance there is an engines field specified in the package, but the range is invalid in some way. Since RegEx for SemVer can be tricky, we return the following, if that's the case:

{
  compatible: 'invalid',
  range: '1 .2 . 0not-a-valid-range'
}

Report module

You can import report (the function that generates a report file when using CLI) as a standalone function to use in your tools to create reports exactly when you need them. It takes two arguments - the first is a result of the depngn function, and the second is an object with options:

interface CliOptions {
  version: string;
  cwd: string | undefined;
  reporter: 'terminal' | 'html' | 'json' | undefined;
  reportDir: string | undefined;
  reportFileName: string | undefined;
}

It returns a promise that resolves as a report file of the given type (html, json) or prints the result to the console if the report is not provided or is terminal.

Usage

import { report } from 'depngn/report';

const createReport = async () => {
  const desiredVersion = '10.0.0';
  const result = await depngn({ version: desiredVersion });
  await report(result, { version: desiredVersion, reportDir: './dependencies-reports', reportFileName: 'depngn' });
};

Supported Package Managers

For now, this package supports npm and yarn. If you want support for your favorite package manager, feel free to open a PR!

Development

In order to start contributing to depngn, you can follow these steps: CONTRIBUTING.md

CHANGELOG

If you want to see what changed between versions: CHANGELOG.md

Possible future features

• Support the ability to sort and/or filter output
• Ignore irrelevant dependencies (ie, @types/<package>)
• Support all node versions (pretty sure this should work going back to node version 10, but if we wrote our own versions of some dependencies, we could support further back. the main offender is table (>=10.0.0), but a lot of modern cli table packages seem to only support node 10 or 12 and above).
• Support attempting to determine support for dependencies that don't include engines field (not sure if it's worth it, since we'd have to fetch the engines of the dependency's dependencies and make an educated guess on what the supported version range is)
• Support pnpm