Rust and web assembly

Introduction:

Rust is a systems programming language that runs blazingly fast, prevents segfaults, and guarantees thread safety. WebAssembly (Wasm) is a low-level bytecode format for the web that runs in modern web browsers and can be used to execute code faster than JavaScript.

Combining the power of Rust and WebAssembly can offer a number of benefits for web development, such as improved performance, access to low-level APIs, and the ability to reuse existing Rust code in the browser.

React is a popular JavaScript library for building user interfaces, and it can be used in combination with Rust and WebAssembly to create interactive web applications. In this blog post, we'll explore how to set up a Rust and WebAssembly project for React, provide some examples of using Rust and WebAssembly in a React app, and discuss best practices and considerations.

Setting up a Rust and WebAssembly project for React:

To get started with a Rust and WebAssembly project for React, you'll need to install a few tools and dependencies.

First, you'll need to install Rust if you don't already have it. You can do this by following the instructions on the Rust website (https://www.rust-lang.org/).

Next, you'll need to install the wasm-pack tool, which is used to build and publish Rust-generated WebAssembly. You can install wasm-pack by running the following command:

cargo install wasm-pack

Once you have wasm-pack installed, you can create a new Rust and WebAssembly project by running the following command:

wasm-pack new my-project

This will create a new directory called my-project with the basic structure of a Rust and WebAssembly project.

To integrate the Rust and WebAssembly project with a React app, you can use the react-wasm library, which provides a set of utilities for using WebAssembly with React. To install react-wasm, run the following command in your React app's directory:

npm install react-wasm

Once you have react-wasm installed, you can import it into your React app and use it to load and use the WebAssembly module generated by wasm-pack.

Here's an example of how to use react-wasm to load and call a function from the WebAssembly module in a React component:

This example uses the useWasm hook provided by react-wasm to load the WebAssembly module and access the exported functions. The instance object returned by the hook contains the exported functions and values, which can be called like any other JavaScript function.

 
import React from 'react';
import { useWasm } from 'react-wasm';
const MyComponent = () => {
    const { instance, loading } = useWasm('./path/to/wasm-module.wasm');
    if (loading) {
        return <div>Loading...</div>;
    }
    return (
        <div>
          <button onClick={() => instance.exported_function()}>
            Call Exported Function
          </button>
        </div>
    );
};
export default MyComponent;

Examples of using Rust and WebAssembly in a React app:

There are a number of ways that Rust and WebAssembly can be used in a React app to improve performance, access low-level APIs, or reuse existing Rust code.

One example of using Rust and WebAssembly to improve performance is to offload computationally expensive tasks to Rust. For instance, if you have a React app that needs to perform a lot of mathematical calculations or data processing, you can write this code in Rust and compile it to WebAssembly to execute it faster than JavaScript.

Here's an example of how to use Rust and WebAssembly to implement a simple function that calculates the Fibonacci sequence in a React component:


import React from 'react';
import { useWasm } from 'react-wasm';
const MyComponent = () => {
  const { instance, loading } = useWasm('./path/to/fibonacci.wasm');
  if (loading) {
    return <div>Loading...</div>;
  }    
  const fibonacci = (n: number) => instance.exported_function(n);
  return (
    <div>
      <button onClick={() => console.log(fibonacci(10))}>
      Calculate Fibonacci(10)       
      </button>     
    </div>   
  ); 
};  
export default MyComponent;

In this example, the fibonacci function is implemented in Rust and compiled to WebAssembly using wasm-pack. The useWasm hook is used to load the WebAssembly module and access the exported exported_function, which is called with a JavaScript number as an argument and returns the result of the Fibonacci calculation.

Another example of using Rust and WebAssembly in a React app is to access low-level APIs or functionality that is not available in JavaScript. For instance, you might want to use Rust and WebAssembly to access hardware-specific features or to interact with a database.

Here's an example of how to use Rust and WebAssembly to access the filesystem in a React app:


import React from 'react';
import { useWasm } from 'react-wasm';
const MyComponent = () => {
  const { instance, loading } = useWasm('./path/to/fs.wasm');
  if (loading) {
    return <div>Loading...</div>;
  }
  const readFile = (path: string) => instance.exported_read_file(path);
  return (
    <div>
      <button onClick={
        () => console.log(readFile('/path/to/file.txt'))
      }>
        Read File
      </button>
    </div>
  );
};
export default MyComponent;

In this example, the readFile function is implemented in Rust and compiled to WebAssembly using wasm-pack. The useWasm hook is used to load the WebAssembly module and access the exported exported_read_file function, which is called with a JavaScript string as an argument and returns the contents of the specified file.

Finally, you can use Rust and WebAssembly to reuse existing Rust code in a React app. This can be especially useful if you have a large codebase

Best practices and considerations:

When using Rust and WebAssembly with React, there are a few best practices and considerations to keep in mind:

Optimize the size of the generated WebAssembly module: WebAssembly modules can be quite large, especially if they include a lot of code or dependencies. To optimize the size of the generated module, you can use tools like wasm-strip and wasm-gc to remove unnecessary code and data from the module. You can also use wasm-opt to optimize the generated code for size and performance.
Handle updates to the Rust code: If you make changes to the Rust code in your project, you'll need to rebuild the WebAssembly module and update the React app to use the new module. You can use tools like wasm-pack and webpack to automate this process and make it easier to update the Rust code in your React app.
Debug and troubleshoot issues: When using Rust and WebAssembly with React, you may encounter issues such as runtime errors or incorrect behavior. To debug and troubleshoot these issues, you can use the browser's developer console and the console.log function to print out debugging information. You can also use tools like wasm-bindgen-cli to generate TypeScript declarations for the WebAssembly module, which can make it easier to debug type-related issues.
Use TypeScript with Rust and WebAssembly: If you're using TypeScript in your React app, you can also use it with Rust and WebAssembly to provide type definitions for the Rust code and improve type checking and code completion. To use TypeScript with Rust and WebAssembly, you can use the wasm-bindgen-cli tool to generate TypeScript declarations for the WebAssembly module.
Use a testing framework: To ensure the reliability and correctness of your Rust and WebAssembly code, you should consider using a testing framework like wasm-bindgen-test or wasm-test-runner. These tools can help you write and run tests for your Rust code and ensure that it is working correctly in the browser.

Conclusion:

In this blog post, we've explored how to use Rust and WebAssembly with React to create interactive web applications. We've looked at how to set up a Rust and WebAssembly project for React, provided some examples of using Rust and WebAssembly in a React app, and discussed best practices and considerations.

Rust and WebAssembly can offer a number of benefits for web development, such as improved performance, access to low-level APIs, and the ability to reuse existing Rust code in the browser. By combining the power of Rust and WebAssembly with the flexibility and simplicity of React, you can create efficient and effective web applications.

If you're interested in using Rust and WebAssembly with React, we encourage you to try it out in your own projects and see how it works for you. With the right tools and approaches, Rust and WebAssembly can be a valuable addition to your web development toolkit.

Matthew
Castrillon-Madrigal

UI Developer at Sky