Endpoint Design Lab for e-commerce checkout backend #1

Code Example

import { z } from "zod";

const createUserSchema = z.object({
  email: z.string().email(),
  password: z.string().min(8),
  role: z.enum(["user", "admin"]).default("user"),
});

export function parseCreateUser(payload: unknown) {
  const result = createUserSchema.safeParse(payload);
  if (!result.success) {
    return {
      ok: false,
      error: result.error.issues.map((issue) => issue.message),
    };
  }
  return { ok: true, data: result.data };
}

console.log("Try endpoint with:", "npm run dev");

Commands & References

• npm init -y
• npm run dev
• node server.js

Lab Steps

1. Prepare environment using: npm init -y
2. Implement endpoint or middleware for this scenario.
3. Test positive/negative cases and inspect response contracts.
4. Document one reliability or security improvement.

Exercises

• Add one edge-case validation and return clear error details.
• Improve one endpoint to be idempotent and test retries.
• Write one test case proving the expected API behavior.