create: nacho-js-process crate

Cargo.toml

@@ -23,6 +23,7 @@ members = [
     "schnorr-signature",
     "proofs-db",
     "macros",
+    "js-process",
 ]
 
 [workspace.dependencies]
@@ -60,6 +61,7 @@ nacho-processes.path = "processes"
 nacho-proofpool.path = "proofpool"
 nacho-proofs-db.path = "proofs-db"
 nacho-prover.path = "prover"
+nacho-js-process.path = "js-process"
 nacho-rpc-server.path = "rpc-server"
 nacho-schnorr-signature.path = "schnorr-signature"
 nacho-withdrawals-db.path = "withdrawals-db"

js-process/Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+name = "nacho-js-process"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+tokio.workspace = true
+thiserror.workspace = true

js-process/resources/echo.mjs

@@ -0,0 +1,5 @@
+import { stdin, stdout } from "node:process"
+
+stdin.on("data", async (chunk) => {
+    stdout.write(chunk)
+})

js-process/src/error.rs

@@ -0,0 +1,12 @@
+use thiserror::Error;
+
+/// The errors that can occur during spawning and interacting with Node.js processes.
+#[derive(Error, Debug)]
+pub enum JsProcessError {
+    #[error("data store disconnected")]
+    Io(#[from] std::io::Error),
+    #[error("stdout couldn't be taken from the js process")]
+    Stdout,
+    #[error("stdin couldn't be taken from the js process")]
+    Stdin,
+}

js-process/src/js_process.rs

@@ -0,0 +1,96 @@
+use std::process::Stdio;
+
+use tokio::{
+    io::{AsyncReadExt, AsyncWriteExt},
+    process::{ChildStdin, ChildStdout, Command},
+};
+
+use crate::error::JsProcessError;
+
+/// Spawns a Node.js process using the given arguments and returns a the standard input and output streams of the process.
+///
+/// # Examples
+///
+/// Spawn a process:
+///
+/// ```rs
+/// let (stdin, stdout) = nacho_js_process::spawn(&["echo.js"])?;
+/// ```
+///
+pub fn spawn(
+    args: &[&str],
+) -> Result<(&'static mut ChildStdin, &'static mut ChildStdout), JsProcessError> {
+    let mut process = Command::new("node")
+        .args(args)
+        .stdin(Stdio::piped())
+        .stdout(Stdio::piped())
+        .stderr(Stdio::inherit())
+        .kill_on_drop(false)
+        .spawn()?;
+
+    let stdin = process.stdin.take().ok_or(JsProcessError::Stdin)?;
+    let stdout = process.stdout.take().ok_or(JsProcessError::Stdout)?;
+
+    Ok((Box::leak(Box::new(stdin)), Box::leak(Box::new(stdout))))
+}
+
+/// Writes the given input to the standard input stream of the process.
+///
+/// And reads the standart output of the process to the given output.
+///
+/// # Examples
+///
+/// Spawn a process:
+///
+/// ```rs
+/// let (stdin, stdout) = nacho_js_process::spawn(&["greeting.js"])?;
+/// ```
+///
+/// Interact with the process:
+///
+/// ```rs
+/// let input = b"Berzan";
+/// let mut output = [0u8; 11];
+/// nacho_js_process::interact(stdin, stdout, &input, &mut output).await?;
+/// assert_eq!(output, b"Hi, Berzan!");
+/// ```
+///
+pub async fn interact(
+    stdin: &mut ChildStdin,
+    stdout: &mut ChildStdout,
+    input: &[u8],
+    output: &mut [u8],
+) -> Result<(), JsProcessError> {
+    stdin.write_all(input).await?;
+    stdout.read_exact(output).await?;
+
+    Ok(())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[tokio::test]
+    pub async fn test_echo_js_process() {
+        let js_file_path = concat!(env!("CARGO_MANIFEST_DIR"), "/resources/echo.mjs");
+
+        let (stdin, stdout) = spawn(&[js_file_path]).unwrap();
+
+        // First try:
+        let input = [111u8; 5];
+        let mut output = [0u8; 5];
+
+        interact(stdin, stdout, &input, &mut output).await.unwrap();
+
+        assert_eq!(output, input);
+
+        // Second try:
+        let input = [222u8; 40];
+        let mut output = [0u8; 40];
+
+        interact(stdin, stdout, &input, &mut output).await.unwrap();
+
+        assert_eq!(output, input);
+    }
+}

js-process/src/lib.rs

@@ -0,0 +1,5 @@
+mod error;
+mod js_process;
+
+pub use error::JsProcessError;
+pub use js_process::{interact, spawn};