First commit

server/lib/errorHandler.js

@@ -0,0 +1,66 @@
+/**
+ * Error Handling Middleware
+ * Centralized error handling for consistent API responses
+ */
+
+/**
+ * Error handler middleware
+ * Catches errors from routes and formats response
+ */
+function errorHandler(err, req, res, next) {
+  // Log error for debugging
+  console.error('Error:', err);
+
+  // Default error response
+  let statusCode = 500;
+  let message = 'Internal server error';
+
+  // Handle specific error types
+  if (err.message) {
+    message = err.message;
+
+    // SQLite constraint errors
+    if (err.message.includes('UNIQUE constraint')) {
+      statusCode = 409; // Conflict
+      message = 'A record with that value already exists';
+    } else if (err.message.includes('FOREIGN KEY constraint')) {
+      statusCode = 400; // Bad Request
+      message = 'Invalid reference to related record';
+    } else if (err.message.includes('NOT NULL constraint')) {
+      statusCode = 400;
+      message = 'Required field is missing';
+    } else if (err.message.includes('CHECK constraint')) {
+      statusCode = 400;
+      message = 'Value does not meet validation requirements';
+    }
+
+    // Custom application errors
+    else if (err.message.includes('not found')) {
+      statusCode = 404;
+    } else if (err.message.includes('Cannot delete')) {
+      statusCode = 400;
+    }
+  }
+
+  // Send error response
+  res.status(statusCode).json({
+    error: message,
+    ...(process.env.NODE_ENV === 'development' && { stack: err.stack })
+  });
+}
+
+/**
+ * 404 Not Found handler
+ * Catches requests to undefined routes
+ */
+function notFoundHandler(req, res) {
+  res.status(404).json({
+    error: 'Route not found',
+    path: req.path
+  });
+}
+
+module.exports = {
+  errorHandler,
+  notFoundHandler
+};