From 2c24249a1d9dc37400b7c98e0488119f5e846b11 Mon Sep 17 00:00:00 2001
From: Berzan <berzan@tutanota.com>
Date: Sun, 28 Apr 2024 19:37:42 +0000
Subject: [PATCH] create: `nacho-js-process` crate

---
 Cargo.lock                    |  9 ++++
 Cargo.toml                    |  2 +
 js-process/Cargo.toml         | 10 ++++
 js-process/resources/echo.mjs |  5 ++
 js-process/src/error.rs       | 12 +++++
 js-process/src/js_process.rs  | 96 +++++++++++++++++++++++++++++++++++
 js-process/src/lib.rs         |  5 ++
 7 files changed, 139 insertions(+)
 create mode 100644 js-process/Cargo.toml
 create mode 100644 js-process/resources/echo.mjs
 create mode 100644 js-process/src/error.rs
 create mode 100644 js-process/src/js_process.rs
 create mode 100644 js-process/src/lib.rs

diff --git a/Cargo.lock b/Cargo.lock
index 4cd386a..9e2375e 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -926,6 +926,14 @@ dependencies = [
  "thiserror",
 ]
 
+[[package]]
+name = "nacho-js-process"
+version = "0.1.0"
+dependencies = [
+ "thiserror",
+ "tokio",
+]
+
 [[package]]
 name = "nacho-liquidities-db"
 version = "0.1.0"
@@ -981,6 +989,7 @@ dependencies = [
  "nacho-burns-db",
  "nacho-data-structures",
  "nacho-executor",
+ "nacho-js-process",
  "nacho-liquidities-db",
  "nacho-mempool",
  "nacho-pools-db",
diff --git a/Cargo.toml b/Cargo.toml
index da6915a..c6c7862 100644
--- a/Cargo.toml
+++ b/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"
diff --git a/js-process/Cargo.toml b/js-process/Cargo.toml
new file mode 100644
index 0000000..87ea0fc
--- /dev/null
+++ b/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
diff --git a/js-process/resources/echo.mjs b/js-process/resources/echo.mjs
new file mode 100644
index 0000000..c1b5722
--- /dev/null
+++ b/js-process/resources/echo.mjs
@@ -0,0 +1,5 @@
+import { stdin, stdout } from "node:process"
+
+stdin.on("data", async (chunk) => {
+    stdout.write(chunk)
+})
diff --git a/js-process/src/error.rs b/js-process/src/error.rs
new file mode 100644
index 0000000..aac1f61
--- /dev/null
+++ b/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,
+}
diff --git a/js-process/src/js_process.rs b/js-process/src/js_process.rs
new file mode 100644
index 0000000..9908c80
--- /dev/null
+++ b/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);
+    }
+}
diff --git a/js-process/src/lib.rs b/js-process/src/lib.rs
new file mode 100644
index 0000000..85b1e60
--- /dev/null
+++ b/js-process/src/lib.rs
@@ -0,0 +1,5 @@
+mod error;
+mod js_process;
+
+pub use error::JsProcessError;
+pub use js_process::{interact, spawn};