Extended DefineList.concat method throws error in a component viewmodel

[green3g]

http://jsbin.com/saqobubevu/edit?html,js,console,output

If I create a new list type that has '#': DefineMapType, and I use that list type in a view model of a component, the error is thrown. It looks like it might be a bug, but I've been wrong before on this, so bear with me :)

Uncaught TypeError: Right-hand side of 'instanceof' is not an object(…)

https://github.com/canjs/can-define/blob/master/list/list.js#L23

Basically, this is what the jsbin looks like:

can.Component.extend({
  viewModel: can.DefineMap.extend({
    items: can.DefineList.extend({
      '#': can.DefineMap.extend({
        text: 'string',
      })
    })
  })
  tag: 'my-tag',
  view: can.stache('{{#each items}}{{text}}{{/each}}')
});

[phillipskevin]

@roemhildtg I think this is a bug and have a PR in to fix it. Until that gets in, you can also make this work by using a static DefineMap property instead of the # prototype property. Basically, change:

let ChildList = can.DefineList.extend('ChildList', {
  '#': Child
});

to

let ChildList = can.DefineList.extend('ChildList', {
  DefineMap: Child
}, {});

I think the way you did it originally is the correct way since it is what is shown in the docs, but just wanted to give you this option in case this is blocking you.

[green3g]

@phillipskevin sounds good. Thanks for the workaround/fix

[phillipskevin]

@roemhildtg the bug here is that this.constructor.DefineMap was changed to #, so the approach I suggested will not work once this issue is fixed. Sorry for the bad advice. I will have a real fix for you today.

[phillipskevin]

@roemhildtg the fix is released as can-define 1.0.5.