Uncaught TypeError: $ is not a function in core-js

Question

I'm trying to install the BigCommerce Open Checkout script, and I'm currently getting this error when I try to run the basic installation locally:

Uncaught TypeError: $ is not a function
at eval (es.array.index-of.js?c975:15)
at Object../node_modules/core-js/modules/es.array.index-of.js

That file is:

'use strict';
var $ = require('../internals/export');
var $indexOf = require('../internals/array-includes').indexOf;
var arrayMethodIsStrict = require('../internals/array-method-is-strict');
var arrayMethodUsesToLength = require('../internals/array-method-uses-to-length');

var nativeIndexOf = [].indexOf;

var NEGATIVE_ZERO = !!nativeIndexOf && 1 / [1].indexOf(1, -0) < 0;
var STRICT_METHOD = arrayMethodIsStrict('indexOf');
var USES_TO_LENGTH = arrayMethodUsesToLength('indexOf', { ACCESSORS: true, 1: 0 });

// `Array.prototype.indexOf` method
// https://tc39.github.io/ecma262/#sec-array.prototype.indexof
$({ target: 'Array', proto: true, forced: NEGATIVE_ZERO || !STRICT_METHOD || !USES_TO_LENGTH }, {
  indexOf: function indexOf(searchElement /* , fromIndex = 0 */) {
    return NEGATIVE_ZERO
      // convert -0 to +0
      ? nativeIndexOf.apply(this, arguments) || 0
      : $indexOf(this, searchElement, arguments.length > 1 ? arguments[1] : undefined);
  }
});

So far, I've tried updating core-js and NPM repeatedly with no luck.

Answer 1

Second time I have been here, I found the solution to this and then forgot, so if for nobody else this is for future me.

From the README https://github.com/bigcommerce/checkout-js

• Node >= v16
• NPM >= v8.
• Unix-based operating system.

The node version didn't matter for me, v18 was fine, but as I'm on windows I needed to do the npm actions in WSL, it won't work on normal windows.

Answer 2

core-js should not be compiled by Babel. When using webpack + babel to compile your code, you need to ensure that the webpack module rule for babel-loader excludes core-js.

Option 1

Tell webpack to not use babel-loader for any of the dependencies in your node_modules. Since core-js is a dependency in node_modules, this excludes core-js from being processed by babel.

// webpack.config.js
// This code snippet shows only the relevant part of the webpack config
module.exports = {
  module: {
    rules: [
      {
        test: /\.m?(j|t)sx?$/,
        // Excluding node_modules means that core-js will not be compiled
        exclude: /node_modules/,
        use: ['babel-loader']
      }
    ]
  }
}

Option 2

Tell webpack to compile all dependencies with babel, except for the core-js dependency:

// webpack.config.js
// This code snippet shows only the relevant part of the webpack config
module.exports = {
  module: {
    rules: [
      {
        test: /\.m?(j|t)sx?$/,
        // Compile all node_modules except core-js
        include: {
          and: [/node_modules/],
          not: [/core-js/]
        },
        use: ['babel-loader']
      }
    ]
  }
}

Relevant Links

• https://github.com/zloirock/core-js/issues/912
• https://webpack.js.org/configuration/module/#ruleexclude
• https://webpack.js.org/configuration/module/#ruleinclude
• https://webpack.js.org/configuration/module/#rule-conditions