Error: Decorating class property failed. Please ensure that proposal-class-properties is enabled and runs after the decorators transform.

[NullVoxPopuli]

This error occurs when I'm consuming a V2 addon that has not complied away class properties.

This is incorrect behavior, because

• my browsertargets all support class properties
• the app has proposal-class-properties, so it should use that
• how does this end up working for regular v2 packages? have we always not been able to use class properties?

Is there a way to tell ember-cli-babel to ignore v2 addons? or maybe only run "if it needs to"?
I guess maybe a core_er_ issue is that ember-cli-babel is incorrectly determining that it needs to run on the v2 addons?

[NullVoxPopuli]

Here is a reproduction: NullVoxPopuli/ember-resources#616
this PR demonstrates that by not compiling away properties, you can see from a 5% to 68% reduction in files size (after minification)

the ember app gives this error:

Error: Decorating class property failed. 
Please ensure that proposal-class-properties is enabled and runs after the decorators transform.

[NullVoxPopuli]

ah ok, getting context back now -- I saw this in the babel output:

function _initializerWarningHelper(descriptor, context) {
  throw new Error('Decorating class property failed. Please ensure that ' + 'proposal-class-properties is enabled and runs after the decorators transform.');
}

how rude