Initial commit

server/middleware/errorHandler.js

@@ -0,0 +1,31 @@
+const { errorResponse } = require('../utils/apiResponse');
+
+const errorHandler = (err, req, res, next) => {
+  let statusCode = err.statusCode || res.statusCode === 200 ? 500 : res.statusCode;
+  let message = err.message || 'Server Error';
+
+  // Mongoose bad ObjectId
+  if (err.name === 'CastError') {
+    message = `Resource not found with id ${err.value}`;
+    statusCode = 404;
+  }
+
+  // Mongoose duplicate key
+  if (err.code === 11000) {
+    const field = Object.keys(err.keyValue)[0];
+    message = `Duplicate field value entered for ${field}. Please use another value.`;
+    statusCode = 400;
+  }
+
+  // Mongoose validation error
+  if (err.name === 'ValidationError') {
+    message = Object.values(err.errors).map(val => val.message).join(', ');
+    statusCode = 400;
+  }
+
+  console.error('[Error Handler]:', err);
+  return errorResponse(res, message, err.errors || [], statusCode);
+};
+
+module.exports = errorHandler;
+