npm equivalent of yarn resolutions?

This does not seem to be supported by npm natively, however this package aims to add this functionality:

https://github.com/rogeriochaves/npm-force-resolutions

Npm equivalent to yarn resolutions is overrides. After the RFC was accepted now there's an epic to watch the progress of implementation. https://github.com/npm/statusboard/issues/343

Edit: This was released in npm v8.3.0

Documentation: https://docs.npmjs.com/cli/v8/configuring-npm/package-json#overrides

To make sure the package foo is always installed as version 1.0.0 no matter what version your dependencies rely on:

{
  "overrides": {
    "foo": "1.0.0"
  }
}

npm is due to support overrides, which is equivalent to yarn's resolutions.

For more information about the current RFC status:

https://github.com/npm/rfcs/blob/latest/accepted/0036-overrides.md

As far as I can tell, npm-force-resolutions does not work with npm v7. The package-lock.json format changed in v7 and npm-force-resolutions no longer updates the relevant fields.

However, it is relatively easy to write a script to restrict your dependency tree to only 1 version of a package, e.g.

#!/usr/bin/env node

/* eslint-disable unicorn/prevent-abbreviations */
/* eslint-disable import/unambiguous */
/* eslint-disable import/no-commonjs */
/* eslint-disable node/shebang */

const fs = require('fs').promises;
const path = require('path');

const main = async (resolutions) => {
  const packageLockFilePath = path.resolve(__dirname, '../package-lock.json');

  for (const [name, version] of Object.entries(resolutions)) {
    const packageLock = JSON.parse(await fs.readFile(packageLockFilePath));

    const packagePaths = Object.keys(packageLock.packages);

    const deletePaths = [];

    for (const packagePath of packagePaths) {
      if (packagePath.endsWith('/' + name)) {
        if (packageLock.packages[packagePath].version !== version) {
          deletePaths.push(packagePath);
        }
      }
    }

    for (const packagePath of deletePaths) {
      for (const deletePath of deletePaths) {
        if (packagePath === deletePath || packagePath.startsWith(deletePath + '/')) {
          // eslint-disable-next-line fp/no-delete
          delete packageLock.packages[packagePath];
        }
      }
    }

    await fs.writeFile(
      packageLockFilePath,
      JSON.stringify(packageLock, null, '  '),
    );
  }
};

main(require('../package.json').resolutions);

This script simply removes all links to dependencies that do not satisfy resolutions defined in package.json.

To execute the script, just add it to package.json scripts and define resolutions field, e.g.

{
  "scripts": {
    "postinstall": "node bin/fix-package-lock.js"
  },
  "resolutions": {
    "webpack": "5.6.0"
  }
}

resolutions is simply a map of package names and the exact versions of those packages that should be kept in the dependency tree, i.e. the above configuration will remove all versions of webpack that are not 5.6.0. As long you install webpack@5.6.0 version as a dependency of the project you are working with, this will guarantee that all packages load the same version of webpack.

For anyone reading this, overrides is now a supported feature of npm since version 8.3.0 :party:

In package.json add something like this to resolve any grapahql package (replace with your package of issue) to the specified version.

  "resolutions": {
    "graphql": "^15.8.0",
    "**/graphql": "^15.8.0"
  },

You can list the packages you have installed with npm list <package name> to see which package is required and where. Untested, but think its working on my machine.