Pug plugin doesn't work for the .vue files

Environments:

• Prettier Version: 1.18.2
• Running Prettier via: CLI
• Runtime: node.js v8.15.0
• Operating System: MacOS

Steps to reproduce:

• clone https://github.com/xorik/prettier-pug-vue
• run prettier --write *.vue

Expected behavior: Template inside the pug.vue should be prettified

Actual behavior: template inside the pug.vue isn’t touched by prettier

If you run prettier --write *.pug, you can see that the plugin itself works perfectly. The plugin developers suggested to write here: (https://github.com/prettier/plugin-pug/issues/5)

[alexander-akait]

/cc @prettier/core thoughts?

[xavxyz]

👋, @prettier/core team! I may have found a hint for people wanting to use @prettier/plugin-pug and Vue templates.

https://github.com/prettier/prettier/issues/5371 references a time when there were troubles with Vue templates written with Pug, Prettier formatting Pug templates as HTML templates.

As far as I understand, it got fixed by ignoring template tags with a lang attribute different to html thanks to a shouldPreserveElementContent function: https://github.com/prettier/prettier/pull/5388/files#diff-0558c7e4048f9cad5b9156aecca77883R40-R47

Should a modification be done directly to shouldPreserveElementContent in prettier/language-html/utils to check for other kind of templating engines depending on the plugins installed?

Or in prettier/language-html/syntax-vue ?

@Shinigami92 (maintainer of @prettier/plugin-pug) also suggested in https://github.com/prettier/plugin-pug/issues/5#issuecomment-536993369:

In my opinion I would suggest to create something like prettier/language-pug/utils.

I would be happy to help for this issue, but I don’t know where to start (yet)! 💯