codegen/src/file.rs

use crate::error::Result;
use proc_macro2::TokenStream;
use std::fs::File;
use std::io::{BufWriter, Write};
use std::path::Path;

pub fn write<P: AsRef<Path>>(path: P, content: TokenStream) -> Result<()> {
    let mut file = File::create(path).map(BufWriter::new)?;
    write!(
        file,
        "// THIS FILE IS AUTOMATICALLY GENERATED; DO NOT EDIT\n\n"
    )?;
    let mut config = rustfmt::Config::default();
    config.set().emit_mode(rustfmt::EmitMode::Stdout);
    config.set().verbose(rustfmt::Verbosity::Quiet);
    config.set().format_macro_matchers(true);
    config.set().normalize_doc_attributes(true);
    let mut session = rustfmt::Session::new(config, Some(&mut file));
    session.format(rustfmt::Input::Text(content.to_string()))?;
    Ok(())
}