IMA.js Babel 6 Polyfill

0.12.0 verified Sat Apr 25 auth: no javascript maintenance

Provides a polyfill for IE9 and IE10 to fix super-constructor calls in the Babel 6 runtime, addressing transpilation issues that affect applications using Babel 6 class inheritance on legacy Internet Explorer versions. Version 0.12.0 is the latest stable release, but the package is in maintenance mode and not actively developed. It is part of the IMA.js ecosystem and intended for use with IMA.js applications, though it can be used as a standalone fix. Alternatives include using Babel 7's @babel/polyfill or core-js for broader IE support.

Common errors

error ReferenceError: Super constructor may not be called in IE9/10 ↓

cause Babel 6 transpiles super() calls incorrectly for IE9 and IE10.

fix

Import ima-babel6-polyfill as the first line of your application entry point.

error polyfill is not a function ↓

cause Trying to use the polyfill as a function or assign its result.

fix

Use bare import or require: import 'ima-babel6-polyfill';

Warnings

deprecated Babel 6 is outdated and no longer supported. Consider migrating to Babel 7+. ↓

fix Upgrade to Babel 7 and use @babel/polyfill or core-js.

gotcha This polyfill only fixes super-constructor calls for IE9 and IE10. It does not cover other Babel 6 polyfills or features. ↓

fix For full polyfill support, consider using @babel/polyfill or core-js with appropriate config.

gotcha Since the package has no exports, importing it in a way that expects a value will return undefined. ↓

fix Use bare import (import '...') or bare require (require('...')).

Install

npm install ima-babel6-polyfill

yarn add ima-babel6-polyfill

pnpm add ima-babel6-polyfill

Imports

imaBabel6Polyfill
wrong
```
const imaBabel6Polyfill = require('ima-babel6-polyfill');
```
correct
```
import 'ima-babel6-polyfill';
```
This is a side-effect polyfill; import without binding. Use ESM import for bundlers.
require polyfill
wrong
```
const polyfill = require('ima-babel6-polyfill');
```
correct
```
require('ima-babel6-polyfill');
```
For CommonJS environments, use bare require. Do not assign to a variable as it returns undefined.

Quickstart

Shows how to import the polyfill and verifies that super constructor works in IE9/10.

// Ensure this is imported before any other code
import 'ima-babel6-polyfill';

class Parent {
  constructor() {
    this.x = 1;
  }
}

class Child extends Parent {
  constructor() {
    super();
    this.y = 2;
  }
}

const child = new Child();
console.log(child.x); // Should log 1 in IE9/10 with polyfill