New rule: no-empty-component-block

[TheAlexLichter]

Please describe what the rule should do:
The rule should avoid empty <style scoped></style>, script or template tags. If there are no style rules, a style tag is not necessary.

Edge case: Tags that have a src attribute (should be valid).

What category should the rule belong to?

• Enforces code style
• Warns about a potential error
• Suggests an alternate way of doing something
• Other (please specify:)

Provide 2-3 code examples that this rule should warn about:

<template>
  <h1>Hey</h1>
</template>

<script></script>

<style scoped></style>

<template>
  <h1>Hey</h1>
</template>

<style scoped></style>

<template>
</template>

<script>
export default { 
  render (h) { return h('div','Hi') }  // Or so
}
</script>

[daerodriguezme]

Do you know if this has any performance impact?

[TheAlexLichter]

Do you know if this has any performance impact?

No, I don't 🙈

[tyankatsu0105]

@ota-meshi
How about refactoring no-empty-pattern or adding an option to the rule?

[ota-meshi]

Hi @tyankatsu0105
I think it's good to add a new rule vue/no-empty-component-block.

Probably with some attributes it should be ignored. e.g. <style src="...">

https://vue-loader.vuejs.org/spec.html#src-imports

[tjx666]

Why this rule can't get auto fix? Any unsafe situation? @ota-meshi @tyankatsu0105

[FloEdelmann]

Please open a new issue to discuss that.