Jest: Requires Babel "^7.0.0-0", but was loaded with "6.26.3"

[salmankhann]

#6662

🐛 Bug Report

Followed the instructions on the jest website to install babel-core to work with Babel7, and also looked at #6662 but nothing seems to help.

The following is the Stacktrace

Requires Babel "^7.0.0-0", but was loaded with "6.26.3". If you are sure you have a compatible version of @babel/core, it is likely that something in your build process is loading the wrong version. Inspect the stack trace of this error to look for the first entry that doesn't mention "@babel/core" or "babel-core" to see what is calling Babel.

      at throwVersionError (node_modules/@babel/helper-plugin-utils/lib/index.js:65:11)
      at Object.assertVersion (node_modules/@babel/helper-plugin-utils/lib/index.js:13:11)
      at _default (node_modules/@babel/plugin-transform-runtime/lib/index.js:82:7)
      at node_modules/@babel/helper-plugin-utils/lib/index.js:19:12
          at Array.map (<anonymous>)

My package.json looks like this

"devDependencies": {
    "@babel/cli": "^7.0.0",
    "@babel/core": "^7.0.1",
    "@babel/plugin-proposal-class-properties": "^7.0.0",
    "@babel/plugin-proposal-decorators": "^7.0.0",
    "@babel/plugin-proposal-export-namespace-from": "^7.0.0",
    "@babel/plugin-proposal-function-sent": "^7.0.0",
    "@babel/plugin-proposal-json-strings": "^7.0.0",
    "@babel/plugin-proposal-numeric-separator": "^7.0.0",
    "@babel/plugin-proposal-object-rest-spread": "^7.0.0",
    "@babel/plugin-proposal-throw-expressions": "^7.0.0",
    "@babel/plugin-syntax-dynamic-import": "^7.0.0",
    "@babel/plugin-syntax-import-meta": "^7.0.0",
    "@babel/plugin-transform-object-assign": "^7.0.0",
    "@babel/plugin-transform-runtime": "^7.0.0",
    "@babel/preset-env": "^7.0.0",
    "@babel/preset-react": "^7.0.0",
    "babel-core": "7.0.0-bridge.0",
    "babel-loader": "^8.0.0",
    "jest": "^23.4.1",
    "jest-cli": "^23.4.1",
    "jest-trx-results-processor": "^0.0.7"
  },
  "dependencies": {
    "@babel/polyfill": "^7.0.0",
    "@babel/runtime": "^7.0.0",
    "babel-plugin-add-module-exports": "^0.2.1"
  }

My .babelrc

{
    "presets": [
        [
            "@babel/preset-env",
            {
                "targets": {
                    "ie": 11
                },
                "useBuiltIns": "usage"
            }
        ],
        "@babel/preset-react"
    ],
    "plugins": [
        "@babel/plugin-transform-runtime",
        "@babel/plugin-syntax-dynamic-import",
        "@babel/plugin-syntax-import-meta",
        "@babel/plugin-proposal-class-properties",
        "@babel/plugin-proposal-json-strings",
        [
            "@babel/plugin-proposal-decorators",
            {
                "legacy": true
            }
        ],
        "@babel/plugin-proposal-function-sent",
        "@babel/plugin-proposal-export-namespace-from",
        "@babel/plugin-proposal-numeric-separator",
        "@babel/plugin-proposal-throw-expressions",
        "@babel/plugin-proposal-object-rest-spread",
        "@babel/plugin-transform-object-assign"
    ]
}

Run npx envinfo --preset jest

  System:
    OS: macOS High Sierra 10.13.6
    CPU: x64 Intel(R) Core(TM) i7-4750HQ CPU @ 2.00GHz
  Binaries:
    Node: 10.10.0 - /usr/local/bin/node
    Yarn: 1.7.0 - /usr/local/bin/yarn
    npm: 6.4.1 - /usr/local/bin/npm
  npmPackages:
    jest: ^23.4.1 => 23.6.0

[MSmashal]

rimraf node_modules
rimraf package-lock.json

"resolutions": { "babel-core": "7.0.0-bridge.0" },
in package.json

install by yarn,it works.

[SimenB]

You don't need resolutions, see example https://github.com/facebook/jest/tree/master/examples/babel-7

You're missing babel-jest dependency.
You might need babel.config.js instead of .babelrc depending in your repo

Please note this issue tracker is not a help forum. We recommend using StackOverflow or our discord channel for questions.

[salmankhann]

You are right I was missing babel-jest (although adding resolutions without babel-jest works too). I had it earlier and it wasn't working and I removed it due to one of the recommendations on SO. Weird its working now, but now I have a different compilation error about exports with jest even though it compiles properly with webpack. I'll try creating an issue on SO for that.

I wanted to create this issue on SO instead of here but thought its a bug with jest because I followed the instructions on the site and it wasn't working.

[mbenadda]

If this may help someone: in some setups you might need the bridge resolution.

Notably if you have some files compiled through ts-jest + babel-jest, and others through an explicitly specified babel-jest only (for example a project in TypeScript that imports lodash-es or some non-compiled react native lib).

In our case ts-jest with babelConfig compiled files using babel 7 as intended, but babel-jest specified directly in transform attempted and failed to compile using babel 6.

[ghost]

I searched on the internet and tried different solutions (attempts). Nothing worked. Among others I also removed package.json and node_modules. What worked is to uninstall babel-jest with having jest as the only module coming from the jest team.
This confuses me because I thought the jest module's responsibility is only parsing test (\(...).+\.test.js\) files. Or does babel the job? Would be a pleasure to enlighten me.
PS: Of course I tried the normal and officially documented way of installation.

{
  (...)
  "devDependencies": {
    "@babel/cli": "^7.2.3",
    "@babel/core": "^7.2.2",
    "@babel/preset-env": "^7.2.3",
    "@babel/preset-typescript": "^7.1.0",
    "@types/jest": "^23.3.12",
    "babel-core": "^7.0.0-bridge.0",
    "jest": "^23.6.0",
    "regenerator-runtime": "^0.13.1",
    "tslint": "^5.12.0",
    "typescript": "^3.2.2"
  },
  "dependencies": {}
}