Uncaught ReferenceError with redux-saga

Question

T'm trying to use redux-saga module.

However I have following error.

Uncaught ReferenceError: regeneratorRuntime is not defined
    at eval (saga.js:5)
    at Object../js/sagas/saga.js (saga.js:393)
    at __webpack_require__ (saga.js:20)
    at eval (configureStore.js:8)
    at Object../js/stores/configureStore.js

saga.js is just simple.

export function* helloSaga(){
    console.log('Hello Sagas!');
}

And I have installed following module.

npm install @babel/polyfill --save

What is happening on it?

Martin Kadlec · Answer 1 · 2019-12-23T14:56:32.790

0

Check your babel configuration.

For @babel/preset-env check the exclude and useBuiltIns options: https://babeljs.io/docs/en/babel-preset-env#exclude

For @babel/preset-transform-runtime check the regenerator option:
https://babeljs.io/docs/en/babel-plugin-transform-runtime#regenerator

Also @babel/polyfill has been deprecated in favor of directly using core-js and regenerator-runtime/runtime in babel 7.4:
https://babeljs.io/blog/2019/03/19/7.4.0#migration-from-core-js-2
https://babeljs.io/docs/en/babel-polyfill

Finally, try explicitly setting path to .babelrc in your babel-loader. I have a theory that babel is using different .babelrc name defaults to resolve it for some of its tasks.
https://babeljs.io/docs/en/options#configfile or
https://babeljs.io/docs/en/options#extends

edited Dec 23 '19 at 14:56

answered Dec 23 '19 at 14:46

Martin Kadlec

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my configuration for `babel.rc` is `{ "presets": [ "@babel/preset-env", "@babel/react" ] }` – tajihiro Dec 24 '19 at 07:55
I don't know what is properly settings. I still have same error. – tajihiro Dec 24 '19 at 07:56

score 0 · Accepted Answer · answered Dec 25 '19 at 03:03

0

Finally I get to use @babel/polyfill even if it is duplicated.

npm install @babel/polyfill --save

import '@babel/polyfill';

export function* helloSaga(){
    console.log('Hello Sagas!');
}

The error does not come out. It worked.

answered Dec 25 '19 at 03:03

tajihiro

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try this: https://github.com/redux-saga/redux-saga/issues/280#issuecomment-291133023 , it works for me – S1ngoooor May 03 '20 at 05:11

Uncaught ReferenceError with redux-saga

2 Answers2