feat(no-unused-properties): mark $props.<prop> as used

[levchak0910]

fixes #2344

@FloEdelmann could you please mark my issue as open again?

[FloEdelmann]

Looks good to me, thanks for the contribution! 🙂

[ota-meshi]

Thank you! Sorry for the late review. The added source code looks good, but doesn't this PR add support for using this.$props in component methods?

[levchak0910]

Hi @ota-meshi, thanks for the review

Initially, I didn't want to support it in <script> because

1. I was afraid of the implementation's complexity
2. On my personal opinion using this.$props.<prop> should be discouraged

but

• with the understanding that my PR was just a half-solution
• after I searched a bit on GitHub, I saw that many people use this.$props.<prop> in their code
• with some more courage and time

I jumped into the code again and luckily it was not as hard as I expected )

So now the rule supports $props.<prop> in both template and script

[ota-meshi]

LGTM! Thank you!