Default values for optional arguments

[willviles]

Optional arguments currently don't work with default values when the argument is undefined or null. This issue has also been observed by @artemgurzhii.

// component.js
@argument(optional('string'))
foo = 'defaultValue'

{{! parent-template.hbs}}
<Component />

{{! component-template.hbs}}
{{log foo}} {{! => undefined}}

Also, setting the value of the optional argument in the component during any point of the component lifecycle does not mutate the value:

// component.js
didInsertElement () {
  super.didInsertElement(...arguments)
  this.set('foo', 'mutatedValue')
}

{{! component-template.hbs}}
{{log foo}} {{! => undefined (still)}}

This is also true when argument values are supplied to the component:

{{! parent-template.hbs}}
<Component @foo="providedValue" />

// component.js
didInsertElement () {
  super.didInsertElement(...arguments)
  this.set('foo', 'mutatedValue')
}

{{! component-template.hbs}}
{{log foo}} {{! => providedValue}}

If this is a bug, I assume it's a problem with the getter logic for optional arguments.

[willviles]

Updating "ember-cli-htmlbars-inline-precompile": "^2.0.0" resolves this issue.

Can you confirm that's the case for you @artemgurzhii?

[artemgurzhii]

@willviles updating ember-cli-htmlbars-inline-precompile still doesn't work for me

[alexlafroscia]

@willviles are you using the beta version? Or the latest "stable" release?

Never mind, your usage examples are obviously the beta version. I should have recognized that -- my bad.

This is interesting for sure. What happens if you drop the optional modifier? It shouldn't be necessary with a default value, since it not being supplied will fall back to your default (and thus actually be of the correct type).

Also, setting the value of the optional argument in the component during any point of the component lifecycle does not mutate the value:

This sounds like a separate problem, potentially. Can you open a separate issue so we can track them independently?