npm package discovery and stats viewer.

Discover Tips

  • General search

    [free text search, go nuts!]

  • Package details

    pkg:[package-name]

  • User packages

    @[username]

Sponsor

Optimize Toolset

I’ve always been into building performant and accessible sites, but lately I’ve been taking it extremely seriously. So much so that I’ve been building a tool to help me optimize and monitor the sites that I build to make sure that I’m making an attempt to offer the best experience to those who visit them. If you’re into performant, accessible and SEO friendly sites, you might like it too! You can check it out at Optimize Toolset.

About

Hi, 👋, I’m Ryan Hefner  and I built this site for me, and you! The goal of this site was to provide an easy way for me to check the stats on my npm packages, both for prioritizing issues and updates, and to give me a little kick in the pants to keep up on stuff.

As I was building it, I realized that I was actually using the tool to build the tool, and figured I might as well put this out there and hopefully others will find it to be a fast and useful way to search and browse npm packages as I have.

If you’re interested in other things I’m working on, follow me on Twitter or check out the open source projects I’ve been publishing on GitHub.

I am also working on a Twitter bot for this site to tweet the most popular, newest, random packages from npm. Please follow that account now and it will start sending out packages soon–ish.

Open Software & Tools

This site wouldn’t be possible without the immense generosity and tireless efforts from the people who make contributions to the world and share their work via open source initiatives. Thank you 🙏

© 2024 – Pkg Stats / Ryan Hefner

@rnx-kit/metro-plugin-duplicates-checker

v3.0.0

Published

Duplicate packages checker

Downloads

60,998

Readme

@rnx-kit/metro-plugin-duplicates-checker

Build npm version

@rnx-kit/metro-plugin-duplicates-checker checks for duplicate packages in your bundle.

Usage

There are several ways to use this package.

The recommended way is to add it as a plugin in your metro.config.js using @rnx-kit/metro-serializer:

 const { makeMetroConfig } = require("@rnx-kit/metro-config");
+const {
+  DuplicateDependencies,
+} = require("@rnx-kit/metro-plugin-duplicates-checker");
+const { MetroSerializer } = require("@rnx-kit/metro-serializer");

 module.exports = makeMetroConfig({
   serializer: {
+    customSerializer: MetroSerializer([DuplicateDependencies()]),
   },
 });

You can also check for duplicate packages after a bundle is created:

const {
  checkForDuplicatePackagesInFile,
} = require("@rnx-kit/metro-plugin-duplicates-checker");

checkForDuplicatePackagesInFile(pathToSourceMapFile, {
  ignoredModules: [],
  bannedModules: [],
});

If you have a source map object, you can pass that directly to checkForDuplicatePackages():

const {
  checkForDuplicatePackages,
} = require("@rnx-kit/metro-plugin-duplicates-checker");

checkForDuplicatePackages(mySourceMap, {
  ignoredModules: [],
  bannedModules: [],
});

Options

| Key | Type | Default | Description | | :------------- | :------- | :------ | :------------------------------------------ | | bannedModules | string[] | [] | List of modules that are banned. | | ignoredModules | string[] | [] | List of modules that can be ignored. | | throwOnError | boolean | true | Whether to throw when duplicates are found. |

Resolving Duplicates

So you have duplicates in your bundle, now what? Depending on your specific needs, we have several options.

Let's use a specific example:

error @fluentui-react-native/text (found 2 copies)
warn   0.21.14 /~/node_modules/@fluentui-react-native/text
warn   0.22.7 /~/node_modules/@fluentui-react-native/link/node_modules/@fluentui-react-native/text

This one occurs because @fluentui-react-native/link declares a dependency on @fluentui-react-native/text using a wide version range, >=0.21.14 <1.0.0.

Our project depends on @fluentui-react-native/text@^0.21.14, but package managers will typically still try to resolve >=0.21.14 <1.0.0 instead of using the existing resolution. This results in the duplicate error we see above.

From here, we have several options:

Manual Dedupe

This method is error-prone, especially if you have a lot of duplicates. It works if you have very few entries. It varies a lot depending on the package manager you're using.

The project in our example uses Yarn Classic: Open yarn.lock and look for @fluentui-react-native/text:

"@fluentui-react-native/[email protected]", "@fluentui-react-native/text@^0.21.14":
  version "0.21.14"
  resolved "https://registry.yarnpkg.com/@fluentui-react-native/text/-/text-0.21.14.tgz#04918a9558770ec551cbdac87ca1534bfccaeffb"
  integrity sha1-BJGKlVh3DsVRy9rIfKFTS/zK7/s=
  dependencies:
    "@fluentui-react-native/adapters" ">=0.11.3 <1.0.0"
    "@fluentui-react-native/framework" "0.11.10"
    "@fluentui-react-native/interactive-hooks" ">=0.24.12 <1.0.0"
    "@fluentui-react-native/theme-tokens" ">=0.25.4 <1.0.0"
    "@fluentui-react-native/tokens" ">=0.21.6 <1.0.0"
    "@uifabricshared/foundation-compose" "^1.14.12"
    tslib "^2.3.1"

"@fluentui-react-native/text@>=0.21.14 <1.0.0":
  version "0.22.7"
  resolved "https://registry.yarnpkg.com/@fluentui-react-native/text/-/text-0.22.7.tgz#bd11768d3cd69337ad2ec4be76ee88d6749ca24f"
  integrity sha1-vRF2jTzWkzetLsS+du6I1nScok8=
  dependencies:
    "@fluentui-react-native/adapters" ">=0.12.0 <1.0.0"
    "@fluentui-react-native/framework" "0.13.6"
    "@fluentui-react-native/interactive-hooks" ">=0.25.7 <1.0.0"
    "@fluentui-react-native/theme-tokens" ">=0.26.5 <1.0.0"
    "@fluentui-react-native/tokens" ">=0.22.5 <1.0.0"
    "@uifabricshared/foundation-compose" "^1.14.20"
    tslib "^2.3.1"

We can see there are two entries, one being resolved to 0.21.14 and the other to 0.22.7. In this case, since we want to keep 0.21.x and the version ranges just happens to be satisfied by this. We can merge the two entries like below:

"@fluentui-react-native/[email protected]", "@fluentui-react-native/text@>=0.21.14 <1.0.0", "@fluentui-react-native/text@^0.21.14":
  version "0.21.14"
  resolved "https://registry.yarnpkg.com/@fluentui-react-native/text/-/text-0.21.14.tgz#04918a9558770ec551cbdac87ca1534bfccaeffb"
  integrity sha1-BJGKlVh3DsVRy9rIfKFTS/zK7/s=
  dependencies:
    "@fluentui-react-native/adapters" ">=0.11.3 <1.0.0"
    "@fluentui-react-native/framework" "0.11.10"
    "@fluentui-react-native/interactive-hooks" ">=0.24.12 <1.0.0"
    "@fluentui-react-native/theme-tokens" ">=0.25.4 <1.0.0"
    "@fluentui-react-native/tokens" ">=0.21.6 <1.0.0"
    "@uifabricshared/foundation-compose" "^1.14.12"
    tslib "^2.3.1"

Now we should only have one copy of @fluentui-react-native/text.

Our example is relatively simple. Sometimes you have to go further up the dependency chain and dedupe dependees.

Fortunately, we can use tools in most cases.

Using Tools

If you're using Yarn Classic, there is a tool, yarn-deduplicate, for deduplicating everything in yarn.lock. You can run it like so:

npx yarn-deduplicate

By default, it will try to dedupe to the highest version. In our example, however, we want to keep using 0.21.x. We should also limit the number of packages that get deduped to make it easier to review later. yarn-deduplicate provides many options, but we'll be using the fewer strategy and the --scopes flag to only target @fluentui-react-native packages:

npx yarn-deduplicate --strategy fewer --scopes @fluentui-react-native

You can read more about yarn-deduplicate and available options here: https://github.com/scinos/yarn-deduplicate#readme

If you're using modern Yarn or other package managers, check out their built-in dedupe command:

  • Yarn: https://yarnpkg.com/cli/dedupe
  • npm: https://docs.npmjs.com/cli/commands/npm-dedupe
  • pnpm: https://pnpm.io/cli/dedupe

Help Metro Resolve Correct Version

If, for some reason, you cannot dedupe the package, you can instead configure Metro to resolve the correct version by telling it which version to use (with resolver.extraNodeModules) and blocking every other copy (with resolver.blockList):

module.exports = {
  resolver: {
    extraNodeModules: {
      "@fluentui-react-native/text":
        "/~/my-project/node_modules/@fluentui-react-native/text",
    },
    blockList: [
      /(?<!\/~\/my-project)\/node_modules\/@fluentui-react-native\/text\/.*/,
    ],
  },
};

You don't have to write these entries manually. We have helper functions in @rnx-kit/metro-config for generating them dynamically.

Last Resort: Force Resolution

As a last resort, if everything else fails, you can manually override package resolutions. We don't recommend this solution because it forces a single version in all workspaces. For example, if you have two projects that have nothing to do with each other, they will both be forced to use the same version even though they could be using different versions. It also adds maintenance overhead because you will have to manually update the version as dependees update theirs.

If you've decided that you have no other options, you can find the appropriate documentation for your package manager below:

  • Yarn: https://yarnpkg.com/configuration/manifest#resolutions
  • npm: https://docs.npmjs.com/cli/v10/configuring-npm/package-json#overrides
  • pnpm: https://pnpm.io/package_json#pnpmoverrides