README.md

The hello example

In this example, we demonstrate how to call a Rust function from a nodejs host through the SSVM. Read about Getting started with Rust functions in Node.js.

Prerequisites

If you have not done so already, follow these simple instructions to install Rust, Node.js, SSVM, and ssvmup.

Create new project

$ cargo new --lib hello
$ cd hello

Change the cargo config file

Add the following to the Cargo.toml file.

[lib]
name = "hello_lib"
path = "src/lib.rs"
crate-type =["cdylib"]

[dependencies]
wasm-bindgen = "0.2.59"

Write Rust code

Below is the entire content of the src/lib.rs file.

use wasm_bindgen::prelude::*;

#[wasm_bindgen]
pub fn say(s: &str) -> String {
  let r = String::from("hello ");
  return r + s;
}

Build the WASM bytecode

$ ssvmup build --enable-aot

Node.js app

Below is the content of the node/app.js file.

const { say } = require('../pkg/hello_lib.js');

const http = require('http');
const url = require('url');
const hostname = '127.0.0.1';
const port = 8080;

const server = http.createServer((req, res) => {
  const queryObject = url.parse(req.url,true).query;
  res.statusCode = 200;
  res.setHeader('Content-Type', 'text/plain');
  res.end(say(queryObject['name']));
});

server.listen(port, hostname, () => {});

Test

node app.js

Result

curl http://127.0.0.1:8080/?name=World!
hello World!