Cannot convert object to primitive value

This is similar to https://github.com/emberjs/ember.js/issues/14187, but I have a reproduction in Ember 2.10 with no addons:

https://ember-twiddle.com/4df2d62bf5f1c05bd74086dc79326020?openFiles=components.my-component.js%2C

The critical ingredient seems to be that I am taking an object created by the hash helper, putting it inside an Array, and passing the array into another component. When such an array hits toString it causes an exception.

(It’s hitting toString in the first place to support an assertion.)

[iStefo]

I have a similar problem when passing a hash into the array helper from https://github.com/DockYard/ember-composable-helpers.

Twiddle that reproduces the issue (note how myComponent.totalLength can’t be computed!): https://ember-twiddle.com/b886a7c23774720188df41e9967aa443?openFiles=templates.application.hbs%2C

“Fixed” by replacing the hash helper with a very simple my-hash helper that returns a full object instead of the EmptyObject that Ember itself uses: (note how now totalLength is shown): https://ember-twiddle.com/208688934ca9599e8607045d3e067fde?openFiles=templates.application.hbs%2C

Edit: The problem occurs in 2.10.2 but also in 2.11 (which is not available in Twiddle)

[rwjblue]

@gabrielgrant / @caseklim - Good spot, I didn’t notice that both were describing the same issue. I’ll close #14922 for now and we can track the issue here.