compile_rustfmt rewrite

[benluiwj]

No description provided.

[ytmimi]

I've been thinking about what the best return type is for build_rustfmt_from_src, and this is what I've come up with. Happy to change the name, but ultimately we need to associate the LD_LIBRARY_PATH with the binary's path, and I think this would work fairly well:

pub struct RustfmtRunner {
    ld_library_path: String,
    binary_path: PathBuf,
}

impl RustfmtRunner {
    fn run(&self, args: &[&str]) -> std::io::Result<std::process::Output> {
        Command::new(&self.binary_path)
            .env("LD_LIBRARY_PATH", &self.ld_library_path)
            .args(args)
            .output()
    }
}

pub fn build_rustfmt_from_src(output_path: PathBuf) -> Result<RustfmtRunner, CheckDiffError> {
    let ld_library_path = get_ld_lib_path()?;

    Command::new("cargo")
        .args(["build", "-q", "--release", "--bin", "rustfmt"])
        .output()?;

    std::fs::copy("target/release/rustfmt", &output_path)?;

    Ok(RustfmtRunner {
        ld_library_path,
        binary_path: output_path,
    })
}

[benluiwj]

@ytmimi i think the approach on build_rustfmt_from_src with RustfmtRunner is promising.

I was wondering if the error for run be an IO error or do you think its better to have a custom error for RustfmtRunner? I was thinking maybe something like GitError but for RustfmtRunner. What do you think?

Also, instead of returning Result<Output>, we return something like Result<(), RustfmtRunnerError>. How do you feel about this?

[ytmimi]

I was wondering if the error for run be an IO error or do you think its better to have a custom error for RustfmtRunner? I was thinking maybe something like GitError but for RustfmtRunner. What do you think?

Also, instead of returning std::io::Result<std::process::Output>, we return something like Result<(), RustfmtRunnerError>. How do you feel about this?

Personally, I don't think we need to get extremely specific with the errors. At the end of the day we're calling Command::output, and I think it's fine to just return std::io::Result<std::process::Output>.

If we ever need to convert the IO error we should be able to do that easily from the caller with the ? operator. Also, having access to the Output is going to be useful since we'll want access to stdout and stderr once we start formatting files with rustfmt.

[ytmimi]

Thanks for your patience on this one. I've left several inline comments with suggestions for how we can improve this further.

[ytmimi]

Thanks for all your hard work on this one. I'm requesting a few changes here, and then I think we'll be good to go. One question I had is whether or not you plan on adding any unit tests? I don't think it's 100% necessary, but I wanted to ask if that was your plan.

If you make my suggested changes and add the following line to fn main() you can run the program with CHECK_DIFF_LOG=info cargo run --bin check_diff -- https://github.com/ytmimi/rustfmt.git subtree_push_automation and see the following output:

fn main() changes

fn main() {
    tracing_subscriber::fmt()
        .with_env_filter(tracing_subscriber::EnvFilter::from_env("CHECK_DIFF_LOG"))
        .init();
    // rest of the main function
}

Log Output

2024-09-26T02:00:07.108055Z  INFO check_diff: Created tmp_dir TempDir { path: "/Users/ytmimi/Documents/Projects/rust_projects/rustfmt/check_diff/.tmpGoVKYx" }
2024-09-26T02:00:08.774163Z  INFO check_diff: Successfully cloned repository https://github.com/rust-lang/rustfmt.git
2024-09-26T02:00:08.774235Z  INFO check_diff: Current directory: /Users/ytmimi/Documents/Projects/rust_projects/rustfmt/check_diff/.tmpGoVKYx
2024-09-26T02:00:08.778775Z  INFO check_diff: Successfully added remote: https://github.com/ytmimi/rustfmt.git
2024-09-26T02:00:10.284677Z  INFO check_diff: Successfully fetched subtree_push_automation.
2024-09-26T02:00:10.312499Z  INFO check_diff: Compiling with cargo 1.83.0-nightly (c1fa840a8 2024-08-29)
2024-09-26T02:00:10.345363Z  INFO check_diff: Building rustfmt from source
2024-09-26T02:00:29.191443Z  INFO check_diff: Successfully switched to subtree_push_automation
2024-09-26T02:00:29.223861Z  INFO check_diff: Building rustfmt from source
2024-09-26T02:00:37.776857Z  INFO check_diff: RUSFMT_BIN rustfmt 1.8.0-nightly (6157568e1c 2024-09-20)
2024-09-26T02:00:37.776891Z  INFO check_diff: Runtime dependencies for (src) rustfmt -- LD_LIBRARY_PATH: /Users/ytmimi/.rustup/toolchains/nightly-2024-09-10-aarch64-apple-darwin/lib
2024-09-26T02:00:38.457874Z  INFO check_diff: FEATURE_BIN rustfmt 1.7.1-nightly (87d9ff0652 2024-09-19)
2024-09-26T02:00:38.457961Z  INFO check_diff: Runtime dependencies for (feature) rustfmt -- LD_LIBRARY_PATH: /Users/ytmimi/.rustup/toolchains/nightly-2024-09-10-aarch64-apple-darwin/lib