catena/parity/src/bin/regen.rs

//! Regenerates the golden files by running the Python oracles.
//!
//! Never run as part of a test: a golden file that regenerates itself when
//! it fails is a test that cannot fail. Run it deliberately, read the diff,
//! and commit the change with the reason.
//!
//! ```text
//! CATENA_PARITY_PYTHON=... CATENA_PARITY_PYTHONPATH=... \
//!     cargo run -p parity --bin regen
//! ```

use std::process::ExitCode;

/// What one oracle run produces: the golden files it wrote, or why it could
/// not.
type Written = Result<Vec<String>, String>;

/// One oracle and the name it is reported under.
type Job = (&'static str, fn() -> Written);

fn main() -> ExitCode {
    let jobs: [Job; 2] = [("tokens", tokens), ("chunkmd", chunkmd)];

    for (name, job) in jobs {
        match job() {
            Ok(written) => {
                for path in written {
                    eprintln!("wrote {path}");
                }
            }
            Err(e) => {
                eprintln!("regen {name}: {e}");
                return ExitCode::FAILURE;
            }
        }
    }
    ExitCode::SUCCESS
}

fn tokens() -> Written {
    let header = format!(
        "# cl100k_base token counts, one per line of parity::sample::standard()\n\
         # seed={:#018x} lines={}\n",
        parity::sample::SEED,
        parity::sample::LINES,
    );
    let counts = parity::run_oracle("tokens.py", &parity::sample::standard())?;
    let path = parity::golden("tokens.counts");
    std::fs::write(&path, format!("{header}{counts}")).map_err(|e| e.to_string())?;
    Ok(vec![path.display().to_string()])
}

fn chunkmd() -> Written {
    let dir = parity::golden("chunkmd");
    std::fs::create_dir_all(&dir).map_err(|e| e.to_string())?;

    let mut written = Vec::new();
    for case in parity::cases("chunkmd") {
        let markdown = std::fs::read_to_string(&case).map_err(|e| e.to_string())?;
        for (set, budgets) in parity::budgets::SETS {
            let records = parity::run_oracle_with(
                "chunkmd.py",
                &parity::budgets::as_args(budgets),
                &markdown,
            )?;
            let path = dir.join(format!("{}.{set}.ndjson", parity::case_name(&case)));
            std::fs::write(&path, records).map_err(|e| e.to_string())?;
            written.push(path.display().to_string());
        }
    }
    Ok(written)
}