You know that moment when your code should work, but it's silently failing? Yeah, that was me last week. I built a user signup API, and it kept throwing vague errors like "Something went wrong" with no details. Super helpful, right?

The Breaking Point

I finally saw this in my logs:

TypeError: Cannot read properties of undefined (reading 'collection')

Turns out, my database connection wasn't actually connecting. I'd forgotten the critical await client.connect()—oops. My connectDB() function was basically a fancy no-op.

What Went Wrong

  1. Ghost Errors

    • My try/catch swallowed errors instead of passing them up
    • Result: Empty error: {} responses. Cool. Very descriptive.

  2. HTTP Codes Gone Wild

    • I used 304 Not Modified for existing users (🤦‍♂️)
    • Reality check: 304 is for caching. 409 Conflict is the correct "user exists" code

  3. Security? What Security?

    • Passwords were flying in plaintext
    • Zero input validation. "What's an injection attack?" – Me, before Google

How I Fixed It

  1. Database Connection Bootcamp

    • Added await client.connect(). Shocking, I know.
    • Cached the connection so it doesn't re-connect every request

  2. Error Handling That Doesn't Suck

    • Started logging errors with console.error
    • Returned actual error messages instead of {}

  3. HTTP Codes That Make Sense

    • 201 Created for new users
    • 409 Conflict for duplicates
    • 500 only for real server meltdowns

  4. Basic Security Hygiene

    • Added bcrypt for password hashing
    • Validated emails (no more "not_an_email" signups)

Lessons Learned

  • Debugging 101: Isolate the damn issue. Test DB connections separately
  • HTTP Codes Matter: A wrong status code confuses everyone (including future you)
  • Never Trust User Input: Validate early, hash passwords, and sanitize everything

Moral of the Story?
If your code fails silently, you're in for a bad time. Log errors, use proper status codes, and always secure user data. Now my signup flow actually works—and doesn't embarrass me. 🎉

— MD Tarekul Islam Sabbir, slightly wiser than last week

User Signup Flow Diagram