Formatter: Show formatting errors before auto-correct (squiggly lines, problem pane)

[Splines]

Thanks a lot for taking a stab at this long-standing issue of no good html+erb linting/formatting options, you really fill a gap there!

I was wondering if the Herb LSP in VSCode could also show formatting-related issues as problems in the problem pane as well as directly in the code, just like the Herb linter does:

For example, from html-eslint I'm used to squiggly lines whenever I don't have the correct indentation. Currently, the Herb Formatter corrects these mistakes on save, I'd just like to also see them directly, even before I hit save.

[marcoroth]

Hey @Splines, thank you for the support and for opening this issue!

That's an interesting feature I haven't really thought about yet. The squiggly lines are currently all provided by the linter, which doesn't know anything about how the formatter formats.

I guess we we could do is to format the document (without writing the the file) and then diff each character that is different from what's currently in the document and add a generic "Document isn't formatted" diagnostic for each character that is different.

[Splines]

and then diff each character that is different from what's currently in the document and add a generic "Document isn't formatted" diagnostic for each character that is different.

Not too sure about this since this wouldn't allow the users to know why part of their code is marked as problematic.

In comparison, here is how ESLint Stylistic shows formatting issues in VSCode. Notice how I can hover over squiggly lines under misplaced spaces or single quotes (instead of double quotes) in order to see the exact error message. The latter even includes a link to their docs: https://eslint.style/rules/no-multi-spaces (just like the Herb linter already does). All problems are listed in the problems pane. Those shown in the image are all gone automatically when I save the document (adjustable).

Further links

• ESLint Core and Formatting
• Linters vs. Formatters

[marcoroth]

Opened a sketch/prototype for this: #1364

Though I'm not 100% sure this is really headed in the right direction