Add Basic Request Validation Middleware

Express.js

Node.js

Technical Specification

Create a middleware validateCreateItem that ensures POST /items has a non-empty 'name' field.

Input/Output Samples

Input:POST /items {}

Output:400 { "error": "name is required" }

Optimal Logic Path

function validateCreateItem(req, res, next) {
  const { name } = req.body;
  if (!name || typeof name !== "string" || !name.trim()) {
    return res.status(400).json({ error: "name is required" });
  }
  next();
}

app.post("/items", validateCreateItem, (req, res) => {
  // create logic...
});

Architectural Deep-Dive

Validation middleware keeps route handlers clean and ensures consistent error responses.