build.rs

use std::path::PathBuf;
use std::{env, fs, io};

/// Base loosely on.
/// See: https://blog.aqd.is/2021/07/rust-protobuf
///
/// License: https://creativecommons.org/licenses/by-sa/4.0/legalcode
fn main() -> io::Result<()> {
    let proto_folder = "proto";

    // Load the files in the resources/proto directory.
    let proto_path = project_root()?.join("resources").join(proto_folder);

    // Save the server output in target/proto/server/*.rs
    let server_out_dir = PathBuf::from(".").join("src").join(proto_folder);

    fs::create_dir_all(server_out_dir.clone())?;

    let proto_include_dir = proto_path.clone();

    let paths = fs::read_dir(proto_path).unwrap();

    // If the filenames change that the build script stays the same!
    for path in paths {
        let path_buf = path.unwrap().path();
        tonic_build::configure()
            .build_server(true)
            .out_dir(server_out_dir.as_path())
            .compile(&[&path_buf.as_path()], &[&proto_include_dir])?;
    }

    println!("cargo:rerun-if-changed=./resources/proto");

    Ok(())
}

fn project_root() -> io::Result<PathBuf> {
    env::current_dir()
}