ember-class-constructor-fix

This addon fixes a common bug that occured in versions of Ember prior to 3.13, where if a particular combination of browser targets was used, it was possible to have failures when attempting to zebra-stripe native and Classic class definitions:

class Foo extends EmberObject {}

const Bar = Foo.extend();

class Baz extends Bar {}

const Qux = Baz.extend();

Zebra-striping here refers to the fact that we are extending using native syntax, then classic syntax, then native syntax again.

The bug came down to Ember using a precompiled build that targeted legacy browsers such as IE11. In some cases, it was possible that Ember would use this build, even though classes didn't need to be transformed. The user's classes would not be transformed, but one particular class in Ember would - the class that is created in EmberObject.extend(). Native classes cannot interop with traditional function based classes, at all, so this breaks completely:

// modern class
class Foo {}

// pre-es6 class
function Bar() {
  // constructor "super"
  return Foo.apply(this, arguments) || this;
}

// breaks
new Bar();

This patches Ember's legacy build if and only if Babel says we aren't going to transform classes. Since class syntax is supported according to Babel/targets, patching it back in won't cause issues, in general.

Compatibility

• Ember.js v3.6 or above
• Ember CLI v2.13 or above
• Node.js v8 or above

Installation

ember install ember-class-constructor-fix

Usage

Once installed the addon does not need further setup.

Contributing

See the Contributing guide for details.

License

This project is licensed under the MIT License.