With symlinked packages: Error: Unable to resolve module `@scope/ui` from `/some/path.js`: Module `@scope/ui` does not exist in the Haste module map

Do you want to request a feature or report a bug?

Bug

What is the current behavior?

I have a lerna monorepo where i decided to scope the packages inside. When I run lerna link --force-local (which essentially symlinks my local packages inside of others if they are mentioned in the package.json) my React Native app at some point will have the following directory in it: ./node_modules/@scope/ui and ui is the symlinked directory.

If I now start the metro bundler and run the app, it will throw following error:

error: bundling failed: Error: Unable to resolve module `@scope/ui` from `/Projects/myMainLerna/packages/myRnApp/index.js`: Module `@scope/ui` does not exist in the Haste module map

I have seen all the other issues around this like https://github.com/facebook/react-native/issues/4968 and https://github.com/facebook/metro/issues/241 and many others, but this is something unrelated to the causes in the other issues.

How do I know it’s a problem with symlinked packages? I simply threw a real copy of my package into my ./node_modules/@scope/ui and it started working. It might be though that symlinked packages, if not put into a scope directory, work - I don’t know because I didn’t try that one.

How to reproduce and a minimal repository on GitHub

https://github.com/mxmzb/MetroLinkedHasteExample and follow the README instructions

What is the expected behavior?

App finds and uses the package.

Please provide your exact Metro configuration and mention your Metro, node, yarn/npm version and operating system.

Note: it doesn’t seem to matter if I use yarn or npm.

Metro configuration: As it comes with React Native node: 8.12.0 yarn: 1.10.1 npm: 6.4.1 All on macOS

[nickarora]

We are dealing with a similar issue using yarn workspaces. Attempts to work around it using extraNodeModules were unsuccessful. Would appreciate if the maintainers could offer recommendations

[MehdiDonk]

Hi, You can try WML. https://www.npmjs.com/package/wml

What it does:

replaces npm link with something that actually works!

It worked for me ! Cheers