`attribute-hyphenation` rule has no effect on event attributes

[churkin]

ESLint Version: 5.4.0
eslint-plugin-vue Version: 4.7.1

Rule:
"vue/attribute-hyphenation": [2, "always"]

Code:

<data-grid
  :showBorders="true"
  keyExpr="ID"
  @selectionChanged="onSelectionChanged"
>

I get two errors, but should three:

6:7 error Attribute ':showBorders' must be hyphenated vue/attribute-hyphenation
8:7 error Attribute 'keyExpr' must be hyphenated vue/attribute-hyphenation

✖ 2 problems (2 errors, 0 warnings)
2 errors and 0 warnings potentially fixable with the --fix option.

[michalsnik]

This is an expected behaviour @churkin But it might be worth it to add an extra rule for forcing hypenation in events too, the rule could both report:

• listener @someEvent=""
• emitter this.$emit('someEvent') (in template and script tag)
  and automatically fix all of them 👍

This seems like a good rule proposition, especially in regard to info from official documentation: https://vuejs.org/v2/guide/components-custom-events.html

Unlike components and props, event names will never be used as variable or property names in JavaScript, so there’s no reason to use camelCase or PascalCase. Additionally, v-on event listeners inside DOM templates will be automatically transformed to lowercase (due to HTML’s case-insensitivity), so v-on:myEvent would become v-on:myevent – making myEvent impossible to listen to.

I looked at the opened issues, and it seems we already have this proposal here: #356

So I'm closing this issue in favour of the former one, let's continue discussion there :)

[acacia314]

@michalsnik I don't think #356 addressed the hyphenation of the event listener attribute, eg @someEvent is still allowed and there's no rule to enforce '@some-event' format like there is for attributes with attribute-hyphenation.