In this tutorial, we will explore how to build a code tester using OpenAI Codex, a state-of-the-art language model, and React, a popular JavaScript library for building user interfaces. The code tester will allow users to write code in various programming languages and see the output or any errors that may occur.
Prerequisites
To follow along with this tutorial, you will need the following:
- Basic knowledge of JavaScript and React
- Node.js installed on your machine
- A code editor of your choice
Setting up the Project
Let’s start by setting up a new React project. Open your terminal and run the following command:
npx create-react-app code-tester
This will create a new directory named code-tester with all the necessary files for a React project.
Navigate into the project directory:
cd code-tester
Now, let’s install axios, a popular library for making HTTP requests, by running the following command:
npm install axios
Creating the CodeTester Component
In the src directory, create a new file called CodeTester.js. This file will contain the main component where the code tester logic will be implemented. Open the CodeTester.js file in your code editor and add the following code:
import React, { useState } from 'react';
import axios from 'axios';
const CodeTester = () => {
const [code, setCode] = useState('');
const [language, setLanguage] = useState('javascript');
const [output, setOutput] = useState('');
const [error, setError] = useState('');
const handleSubmit = async (e) => {
e.preventDefault();
try {
const response = await axios.post('/api/code-tester', { code, language });
setOutput(response.data.output);
setError(response.data.error);
} catch (error) {
console.error(error);
}
};
return (
<div>
<form onSubmit={handleSubmit}>
<div>
<label htmlFor="code">Code:</label>
<textarea id="code" value={code} onChange={(e) => setCode(e.target.value)} />
</div>
<div>
<label htmlFor="language">Language:</label>
<select id="language" value={language} onChange={(e) => setLanguage(e.target.value)}>
<option value="javascript">JavaScript</option>
<option value="python">Python</option>
<option value="java">Java</option>
</select>
</div>
<button type="submit">Run Code</button>
</form>
{output && (
<div>
<h2>Output:</h2>
<pre>{output}</pre>
</div>
)}
{error && (
<div>
<h2>Error:</h2>
<pre>{error}</pre>
</div>
)}
</div>
);
};
export default CodeTester;
This component defines a form with two inputs: a textarea for the code and a select dropdown for selecting the programming language. It also includes a “Run Code” button that triggers the handleSubmit function when clicked.
The useState hook is used to manage the state of the code, language, output, and error. The handleSubmit function makes an HTTP POST request to /api/code-tester with the code and language as the request payload. The response is then used to update the output and error state variables.
Creating the Server-side Endpoint
To handle the code execution on the server-side, we need to create an API endpoint that receives the code and language, executes the code, and returns the output or any errors. In the root of your project directory, create a new directory called server. Inside the server directory, create a new file called app.js. Open the app.js file in your code editor and add the following code:
const express = require('express');
const { PythonShell } = require('python-shell');
const axios = require('axios');
const app = express();
app.use(express.json());
app.post('/api/code-tester', async (req, res) => {
const { code, language } = req.body;
let result = { output: '', error: '' };
try {
if (language === 'javascript') {
// Use eval to execute JavaScript code
result.output = eval(code);
} else if (language === 'python') {
// Use PythonShell to execute Python code
await new Promise((resolve, reject) => {
PythonShell.runString(code, null, (err, output) => {
if (err) {
reject(err);
} else {
result.output = output.join('n');
resolve();
}
});
});
} else if (language === 'java') {
// Send Java code to an external compiler API
const response = await axios.post('https://api.jdoodle.com/v1/execute', {
clientId: 'your-jdoodle-client-id',
clientSecret: 'your-jdoodle-client-secret',
script: code,
language: 'java',
versionIndex: '3',
});
if (response.data.compile_output) {
result.output = response.data.compile_output;
} else {
result.output = response.data.output;
}
}
} catch (error) {
result.error = 'An error occurred while executing the code.';
}
res.json(result);
});
const port = process.env.PORT || 5000;
app.listen(port, () => {
console.log(`Server is running on port ${port}`);
});
This server code uses Express, a minimal and flexible Node.js web application framework, to handle HTTP requests. We define a single API endpoint /api/code-tester that accepts a POST request. The code and language are extracted from the request body.
Depending on the selected language, the code is executed using different approaches:
- For JavaScript, the
evalfunction is used to execute the code. - For Python, the
PythonShelllibrary is used to execute the code provided. - For Java, the code is sent to JDoodle’s API for compilation and execution.
The response containing the output or error is sent back as a JSON object.
Make sure to replace your-jdoodle-client-id and your-jdoodle-client-secret with your own JDoodle credentials if you plan to use Java for code execution.
Wiring Everything Together
Now that we have both the client-side and server-side code in place, we need to wire them together.
In the src directory, locate the index.js file and open it in your code editor. Replace the existing code with the following:
import React from 'react';
import ReactDOM from 'react-dom';
import CodeTester from './CodeTester';
import './index.css';
ReactDOM.render(
<React.StrictMode>
<CodeTester />
</React.StrictMode>,
document.getElementById('root')
);
This code imports and renders the CodeTester component, which we created earlier, inside the root HTML element with the ID of root.
Finally, go back to the CodeTester.js file and modify the form’s onSubmit event handler like this:
const handleSubmit = async (e) => {
e.preventDefault();
try {
const response = await axios.post('http://localhost:5000/api/code-tester', {
code,
language,
});
setOutput(response.data.output);
setError(response.data.error);
} catch (error) {
console.error(error);
}
};
By default, Axios makes requests to the same domain that served the React application, which in our case is localhost:3000. However, we need to make requests to our server running on localhost:5000. Therefore, we prepend the server URL to the request URL.
Running the Code Tester
Now that everything is set up, let’s run our code tester. In the root of your project directory, open the terminal and run the following command:
npm start
This will start the development server and automatically open the app in your default web browser. You should see the code tester interface with a code textarea, a language select dropdown, and a “Run Code” button.
Once you write some code in the textarea and select a language from the dropdown, click the “Run Code” button. The output or any error message will be displayed below. Depending on the language selected, the code may be executed in different ways.
Congratulations! You have successfully built a code tester using OpenAI Codex and React.
Conclusion
In this tutorial, we explored how to build a code tester using OpenAI Codex and React. We leveraged the power of OpenAI Codex to execute code written in JavaScript, Python, and Java. We also used the Axios library to make HTTP requests from the React client to the server-side endpoint. By following this tutorial, you now have a strong foundation to build more advanced code testing applications with these technologies.
Play around with the code tester, add more features, and explore additional programming languages. Have fun coding!