created custom middleware

__tests__/middleware.test.js

@@ -1,6 +1,6 @@
 // middleware.test.js
 const request = require('supertest');
-const app = require('./index'); // Adjust the path as needed to import your Express app
+const app = require('../index'); // Adjust the path as needed to import your Express app
 
 describe('Conditional Middleware Validation', () => {
   test('POST /validate-data with isValid=true should proceed and return 200', async () => {

index.js

@@ -0,0 +1,19 @@
+const express = require('express');
+const app = express();
+
+const validateRequestData = (req, res, next) => {
+    const isValid = req.body.isValid;
+    if (isValid === true) {
+        next();
+    } else {
+        res.status(400).send('invalid request data');
+    }
+};
+
+app.use(express.json());
+
+app.post('/validate-data', validateRequestData, (req, res) => {
+    res.status(200).send('data is valid');
+});
+
+module.exports = app;