Validate `triagebot.toml` in tidy/CI

[compiler-errors]

Would've prevented #106102, which broke in #105661.

We should at least validate the toml file is valid syntax, but ideally we'd validate more context-specific stuff.

[jyn514]

Mentoring instructions: Add a new check to tidy around here that parses triagebot.toml to make sure it's valid toml:

rust/src/tools/tidy/src/lib.rs

Lines 41 to 58 in 17395b4

	pub mod alphabetical;
	pub mod bins;
	pub mod debug_artifacts;
	pub mod deps;
	pub mod edition;
	pub mod error_codes_check;
	pub mod errors;
	pub mod extdeps;
	pub mod features;
	pub mod mir_opt_tests;
	pub mod pal;
	pub mod primitive_docs;
	pub mod style;
	pub mod target_specific_tests;
	pub mod ui_tests;
	pub mod unit_tests;
	pub mod unstable_book;
	pub mod walk;

See the existing tidy files for an example of how to write a tidy check.

[aadityadhruv]

Hi, I'm a new contributor here and thought of picking this as my first issue. From what I understand, a new crate (something like triagebot.rs) needs to be made for this issue right? Where we can parse the toml and see if it is valid.

[jyn514]

@aadityadhruv a new module, not a new crate. The module should be part of tidy so check runs on x test tidy.

[aadityadhruv]

Right, that makes sense. Thank you!

[aadityadhruv]

Hi, sorry for the late response, I was out traveling. I'm currently confused about a certain thing. Currently what I am trying to do is manually check the file for valid syntax, by going over it line by line. Is this the correct method to do this, or should I be using an already existing crate like toml? I would assume that extra crate dependencies aren't probably wanted.

Also, I was wondering something about Path in the check function. For this module, would I need to check/filter any paths like some other modules do? I was assuming that I will simply open path + 'tiragebot.toml' and read that file.

Any help is appreciated!

[jyn514]

should I be using an already existing crate like toml?

Yes, please use toml, don't use regex or anything like that.

[ehuss]

I personally would prefer to see this implemented in triagebot itself instead of tidy. That would make it work for all repositories. It should be fairly trivial to add a handler that checks for a PR that modifies triagebot.toml and to validate it, and post a comment if it is not correct. It can even use the Config type to verify that the actual structure matches. Bonus points would to also use serde-ignored to enforce that unknown fields aren't included.

[dotdot0]

@aadityadhruv are you still working on this?

[aadityadhruv]

Hi, yeah I'm sorry, I'm still working on it. I've been pretty busy the last couple of days, I'll get it done this week itself. Hope that's ok!

[dotdot0]

Hi, yeah I'm sorry, I'm still working on it. I've been pretty busy the last couple of days, I'll get it done this week itself. Hope that's ok!

Yeah! it's alright

[aadityadhruv]

I personally would prefer to see this implemented in triagebot itself instead of tidy. That would make it work for all repositories. It should be fairly trivial to add a handler that checks for a PR that modifies triagebot.toml and to validate it, and post a comment if it is not correct. It can even use the Config type to verify that the actual structure matches. Bonus points would to also use serde-ignored to enforce that unknown fields aren't included.

Sorry for being slow with the issue, but along with being busy, I've been kinda stuck, and was unsure if I should ask for help. I am currently unsure if I should be doing work in tidy or the triagebot repository. Should I first try to get the tidy check working and then maybe open an issue on the triagebot repo?

[aadityadhruv]

Here is the code I had written (it does not work since I do not know what the configuration of the toml is):

use crate::walk::{filter_dirs, walk};
use serde::Deserialize;
use std::path::Path;

#[derive(Deserialize)]
struct Config {}

pub fn check(path: &Path, bad: &mut bool) {
    walk(path, &mut |path| filter_dirs(path), &mut |entry, contents| {
        let file = entry.path();
        let filename = file.file_name().unwrap();
        if filename != "triagebot.toml" {
            return;
        }
        let conf: Result<Config, toml::de::Error> = toml::from_str(contents);
        match conf {
            Ok(_) => {}
            Err(_err) => {
                tidy_error!(bad, "{} is an invalid toml file", file.display())
            }
        }
    });
}

I am unsure what would be the right next step here.