--check output is editor-unfriendly.

[eddyb]

While the ergonomic problem will likely go away whenever I get around to moving my setup to VSCode Remote, the current --check diff output is still pretty frustrating, and inconsistent with compiler output.

The head of each diff chunk looks like this: (base dir omitted for clarity)

Diff in .../src/librustc_infer/infer/error_reporting/need_type_info.rs at line 48:

I suspect the at line 48: formatting is trying to be user-friendly or something, but if it was like this, it would be accessible without having to go to the line manually:

Diff at .../src/librustc_infer/infer/error_reporting/need_type_info.rs:48:

For me it's Ctrl+click that I use, but I recall seeing an issue about some other editor (emacs perhaps?), where a more specific format might be needed, I just can't find that issue now.

[calebcartwright]

When you say editor-unfriendly, what's the context? Editor/IDE plugins that facilitate running rustfmt (on-demand, format-on-save) or something else?

Would the json rustfmt output be helpful at all?

[eddyb]

I mean editors/IDE natively handling the text output, where file:line:col is sort of the "standard".

In my case, rustfmt is ran by x.py aka bootstrap/"rustbuild" in the rust-lang/rust repo, and the output is just in a terminal window, but like I was saying earlier, if it were adhering to file:line, Ctrl+click would "just" work to let me jump to that file and line.
Curretly, I have to Ctrl+click to open the file and Ctrl+G to the line manually.

Would the json rustfmt output be helpful at all?

No, since something would have to process it. At that point I should bite the bullet and switch to VSCode Remote to the server, where I could just run RLS, have format on save, etc.

---

What I'm hoping for is a tiny tweak to the --check diff output, to be clear.

[calebcartwright]

if it were adhering to file:line, Ctrl+click would "just" work to let me jump to that file and line.

👍 makes sense, thank you. I'd never noticed that type of navigation in editors before

What I'm hoping for is a tiny tweak to the --check diff output, to be clear.

Seems reasonable to me. It's indeed a really easy change if anyone is interested in making the update, otherwise I can probably get around to it eventually

rustfmt/rustfmt-core/rustfmt-emitter/src/diff.rs

Lines 34 to 38 in 9124dd8

	print_diff(
	mismatch,
	|line_num| format!("Diff in {} at line {}:", filename, line_num),
	&self.config,
	);

[eddyb]

FWIW, I found a way to run rustfmt on save without RLS, so just in case it helps anyone:
https://marketplace.visualstudio.com/items?itemName=pucelle.run-on-save + this config:

    "runOnSave.commands": [
        {
            "match": "\\.rs$",
            "command": "rustfmt --edition=2018 ${file}",
            "runIn": "backend",
        }
    ],

EDIT: added --edition=2018 so that it doesn't break on some rust-lang/rust files.