Cannot find module 'babel-core'

[ingro]

Hello, I've updated jest from 20.0.4 to latest (21.2.1) and got this error for all my tests:

 FAIL  tests\helpers\validator.test.js
  ● Test suite failed to run

    Cannot find module 'babel-core'

      at Function.Module._resolveFilename (module.js:536:15)
      at Function.Module._load (module.js:466:25)
      at Module.require (module.js:579:17)
      at require (internal/module.js:11:18)

Strange thing is that babel-core (v 6.26.0) is installed and listed in my package.json file.
Rolling back to 20.x solves the problem. I see that there are a lot of similar issues but they all seems related to babel v7, while I've problems with babel v6.

[thymikee]

This is most probably related to your package manager, not Jest. I'll close this but feel free to discuss.

[ingro]

By package manager you mean yarn? I also tried to install dependencies with npm after a full clean of node_modules folder but got the same results.

[luan03]

I have the same issue, also I've tried to change jest version and babel-core without any success so, I'll try to figure out why and then post here.

[JasonJJFS]

I have the same issue as well.

[luan03]

Hi @JasonJJFS,

I did these changes above and worked, not as I was expecting but worked:

I've created a .babelrc file and included this:

{
    "presets": ["@babel/preset-env","@babel/preset-react"]
}

Then, in my package.json file, I removed the node "presets": []

This worked for me and I hope that can help you.

[demsking]

I have the same issue and there are my project doesn't use babel. I just have standard and jest as dependencies.

[lokers]

add to package.json

"devDependencies": {
  "babel-core": "^7.0.0-bridge.0"
}

create empty file named /babel.config.js

add to .babelrc to presets:
"@babel/preset-env"

[petejodo]

if you build babel-jest on master the built output is correctly requiring @babel/core but babel-jest@23.6.0 built output requires babel-core so somewhere between that release and master, the build process changed but I can't find anything in the changelog that mentions it. This should be fixed once the next release of jest occurs at least.

[SimenB]

In the changelog:

[*] [BREAKING] Upgrade to Babel 7, dropping support for Babel 6 (#7016)

[SimenB]

But as long as you install babel-core@bridge jest will use babel 7 even on jest 22 and 23

[LongCheng00]

add to package.json

"devDependencies": {
  "babel-core": "^7.0.0-bridge.0"
}

create empty file named /babel.config.js

add to .babelrc to presets:
"@babel/preset-env"

Thank you very much, It works :)

[bluedistro]

Installing babel-core bridge did the trick for me. Thanks

[github-actions]

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