fn clean_files(pattern: &str) -> Result<(), Box<dyn Error>> {

    let files: Result<Vec<PathBuf>, _> = glob(pattern)?.collect();

    files?.iter().try_for_each(|path| {

        remove_file(path)?;

        Ok(())

    })

}

pub fn coverage(arguments: Vec<String>) -> Result<(), Box<dyn Error>> {

    let _ = remove_dir_all("target/coverage");

    create_dir_all("target/coverage")?;

    println!("=== running coverage ===");

    let mut base_directory = env::current_dir().unwrap();

    base_directory.push("target");

    base_directory.push("coverage");

    let mut prof_directory = base_directory.clone();

    prof_directory.push("cargo-test-%p-%m.profraw");

    cmd("cargo", arguments)

        .env("CARGO_INCREMENTAL", "0")

        .env("RUSTFLAGS", "-C instrument-coverage -Z coverage-options=condition")

        .env("LLVM_PROFILE_FILE", prof_directory)

        .run()?;

    println!("ok.");

    println!("=== generating report ===");

    let (fmt, file) = ("html", "target/coverage/html");

    cmd!(

        base_directory,

        fmt,

        file,

    .run()?;

    println!("ok.");

    println!("=== cleaning up ===");

    clean_files("**/*.profraw")?;

    println!("ok.");

    println!("report location: {file}");

    Ok(())

}