fix(utils): also recognize .tsx files as Vue files

[haoqunjiang]

I was testing eslint-config-vue integration with TypeScript projects.
I was surprised to find out that the rule vue/multi-word-component-names does not error on .tsx files, such as Foo.tsx, while it correctly showed errors for Foo.jsx and Foo.vue.

Digging into the rule source code I found that it's because isVueFile('Foo.tsx') always returns false:

eslint-plugin-vue/lib/rules/multi-word-component-names.js

Line 120 in 2dc606c

utils.isVueFile(fileName) &&

[FloEdelmann]

Could you please add a test case?

[haoqunjiang]

Thanks for the feedback!
Initially, I didn't know there were corresponding tests for this simple utility function.
Now I've found them and added the TSX case.

[FloEdelmann]

Great, thank you!

[ota-meshi]

Thank you!