parcel: Uncaught ReferenceError: regeneratorRuntime is not defined

🐛 bug report

When I started using generators in my code. I got the error message when running : Uncaught ReferenceError: regeneratorRuntime is not defined.

🎛 Configuration (.babelrc, package.json, cli command)

{
  "plugins": [
    ["@babel/plugin-transform-runtime", {
      "corejs": 2
    }]
  ]
}

  "devDependencies": {
    "babel-cli": "^7.0.0-beta.3",
    "babel-core": "^7.0.0-beta.3",
    "babel-plugin-transform-class-properties": "^7.0.0-beta.3",
    "babel-plugin-transform-object-assign": "^7.0.0-beta.3",
    "babel-plugin-transform-runtime": "^7.0.0-beta.3",
    "babel-preset-es2015": "^7.0.0-beta.3",
    "babel-preset-react": "^7.0.0-beta.3",
    "babel-preset-stage-0": "^7.0.0-beta.3",
    "babel-runtime": "^7.0.0-beta.3",
    "babelify": "^7.3.0",
    "parcel-bundler": "^1.10.3",
    "qunitjs": "^1.20.0"
  },
  "dependencies": {
    "babel-polyfill": "^7.0.0-beta.3"
  }

🤔 Expected Behavior

generator should just work.

😯 Current Behavior

Uncaught ReferenceError: regeneratorRuntime is not defined
    at Object.parcelRequire.../src/index.js../helpers (index.js:4)
    at newRequire (test.e31bb0bc.js:49)
    at localRequire (test.e31bb0bc.js:55)
    at Object.parcelRequire.graph-edge-traversal.specs.js.qunitjs (graph-edge-traversal.specs.js:2)
    at newRequire (test.e31bb0bc.js:49)
    at localRequire (test.e31bb0bc.js:55)
    at Object.parcelRequire.index.js../graph-edge-traversal.specs (index.js:1)
    at newRequire (test.e31bb0bc.js:49)
    at parcelRequire.../node_modules/process/browser.js (test.e31bb0bc.js:81)
    at test.e31bb0bc.js:107

💁 Possible Solution

This is related to #1762. However, adding import "babel-polyfill" in my index.js made it work. I however cannot do that, I bundle with rollup and that breaks my rollup bundle.

🔦 Context

💻 Code Sample

Cf. test directory Cf. package.json

🌍 Your Environment

    "babel-runtime": "^7.0.0-beta.3",
    "parcel-bundler": "^1.10.3",

Software	Version(s)
Parcel	1.10.3
Node	8.2.0
npm/Yarn	npm
Operating System	windows 10

About this issue

Original URL
State: closed
Created 6 years ago
Reactions: 20
Comments: 15 (1 by maintainers)

Commits related to this issue

In order to fix "regeneratorRuntime is not defined" error See more details here: - https://flaviocopes.com/parcel-regeneratorruntime-not-defined/ - https://github.com/parcel-bundler/parcel/issues/212... — committed to willianantunes/rave-of-phonetics by willianantunes 3 years ago

Most upvoted comments

how to solve ?

If you are targeting modern browsers, a simple solution is to add the browserslist property to your package.json file

{
    "name": "my-app",
    ...
    "browserslist": [
        "last 1 Chrome versions"
    ],
    ...
}

Note: you can change last 1 to last 2 or 3 or however far back you decide to go

+74

felipemullen on Sep 13, 2019

Closing as it’s a duplicate

+21

DeMoorJasper on Nov 14, 2018

how to solve ?

+15

crapthings on Apr 28, 2019

how to solve ?

If you are targeting modern browsers, a simple solution is to add the browserslist property to your package.json file
{
    "name": "my-app",
    ...
    "browserslist": [
        "last 1 Chrome versions"
    ],
    ...
}
Note: you can change last 1 to last 2 or 3 or however far back you decide to go

Hey! I did it, but still the issue.

+12

andreamendi on Oct 4, 2019

I’ve had the same issue. Downgrading to parcel@1.9 solved it.

nihey on Oct 31, 2018

Add to your package.json "browserslist": [ "last 2 Chrome versions" ]

you can change the browser you’re using, It doesn’t have to be only chrome

amrayoub on Jun 14, 2020

 "browserslist": [
        "last 1 Chrome versions"
    ],

does not solve the issue if you need to debug for safari

dy on Mar 29, 2020

Duplicate? https://github.com/parcel-bundler/parcel/issues/1762

wareus on Nov 13, 2018

"browserslist": [
        "last 1 Chrome versions"
    ],

this solved problem for me. @felipemullen thank you!

BobanBg79 on May 23, 2020

It doesn’t appear to be documented within on the parcel website, but looking at the npm package it appears to depend on babel, and babel in turn has a dependency on the browserslist package, which uses that configuration.

You can read more about it and how to configure properly here: https://github.com/browserslist/browserslist

felipemullen on Oct 29, 2019