Cannot resolve babel module when using react-scripts@next

Is this a bug report?

Yes, for react-scripts 2.0. (edit: originally I had believed this to be related to workspaces, but after more testing, it is not - this happens without a monorepo/workspaces. All details below updated to reflect that with a simpler test case.)

Did you try recovering your dependencies?

Yes. I deleted both the workspace and CRA app node_modules and lock files, and reinstalled with yarn (v1.6.0); deleted everything again and tried with npm (v5.6.0) with the same result.

Which terms did you search for in User Guide?

I followed the steps outlined in the roadmap for react-scripts 2.0 to initialize the app.

Environment

MacOS High Sierra 10.134 node 10.1.0 yarn 1.6.0 create-react-app@next react-scripts@2.0.0-next.66cc7a90

I executed this command to init a new CRA2 app: npx create-react-app@next --scripts-version=2.0.0-next.66cc7a90 test

Steps to Reproduce

1. Create a CRA2 app with the command above in the packages (or, in my example, “exercises” folder)
2. In the App.js file, attempt to import getPrototypeOf from @babel/runtime/helpers/getPrototypeOf
3. Run yarn start in either the CRA2 app or the workspace root

(Note: I discovered this issue originally when I installed semantic-ui-react and attempted to use one of its components, which resulted in this error. To simplify the demo I just attempted to import getPrototypeOf in App.js.)

Expected Behavior

CRA app compiles and runs

Actual Behavior

A compilation error occurs: Module not found: Can't resolve '@babel/runtime/helpers/getPrototypeOf' in '/Users/nloding/code/oss/cra2-workspace-broken-ref/src'

I also see this warning when installing the dependencies, I am unsure if it is related? npm WARN @babel/plugin-syntax-dynamic-import@7.0.0-beta.34 requires a peer of @babel/core@7.0.0-beta.34 but none is installed. You must install peer dependencies yourself.

Reproducible Demo

https://github.com/nloding/cra2-workspace-broken-ref

The broken line: https://github.com/nloding/cra2-workspace-broken-ref/blob/master/src/App.js#L6

[nloding]

Got it, thanks - I’ll keep an eye out for the next alpha announcement and test it out.

[venikx]

Currently I’m running an ejected version on my local machine with an updated Jest version and when I push to the repo I make sure the tests don’t run, because they will fail with version the repo has. It’s a bit of a mess, but at least I can keep writing my tests now.