The Tiny Habit That Quietly Kills Bugs Before They Ship

Most bugs don’t come from ignorance.

They come from hurry.

You knew you should have handled the empty array. You meant to add that error check. You planned to write one more test. Then the Slack pinged, the stand-up started, and your half-baked commit slipped into main.

This post is about a ridiculously small practice that acts as a last “quality gate” before your code enters the repo:

The One-Note Coding Nudge — a sub‑minute, single-note pre-commit ritual that forces you to pause, scan for common bug sources, and make your future self’s life easier.

It’s not a tool, not a framework, not a process overhaul. It’s a tiny checklist + a slightly slower commit flow that can quietly cut your defect rate by a lot — in many teams, practices like this eliminate well over half of preventable bugs.

Why You Need a Pre-Commit Ritual (Even if You “Know All This Stuff”)

You’ve seen these best practices before:

• Handle null and empty inputs
• Think about edge cases
• Check error paths
• Write clear commit messages

The problem isn’t knowing them. The problem is remembering them at the moment that matters — right before your code becomes part of the repo’s history.

A pre-commit ritual does three important things:

1. Creates a pause. It breaks the “type → commit → push” autopilot.
2. Surfaces what you forgot. A short checklist reminds you of invisible failure modes.
3. Leaves a trail. Good commit messages document your assumptions, trade-offs, and potential risk areas.

Over days, this feels trivial. Over months, it compounds into a dramatically cleaner codebase.

The One-Note Checklist: Your Last-Second Bug Filter

You don’t need a wiki, a PDF, or a company-wide initiative.

You need one note.

Open your note-taking app, or create a PRE_COMMIT.md in your repo, and add a short bullet list like this:

Pre-Commit Nudge

1. Inputs & edge cases checked?
   - null / undefined / None
   - empty string / list / collection
   - weird sizes (0, 1, max, huge)

2. Errors & failures handled?
   - what happens on network/db/IO failure?
   - do we log or surface meaningful errors?

3. Performance okay for realistic scale?
   - any obvious N+1 loops or O(n^2) on big sets?

4. Clean code pass?
   - names clear?
   - functions small and focused?
   - responsibilities well-separated?

5. Quick debug/verification?
   - targeted tests run?
   - invariants asserted?
   - failure paths walked through mentally?

6. Commit message ready?
   - clear “why”, assumptions, trade-offs?

That’s it. That’s the ritual.

Before every commit, glance at this note and nudge your brain through each item. It should take under a minute for small changes and maybe two for big ones.

This isn’t about perfection. It’s about catching the 20% of issues that cause 80% of production pain.

Using Your Editor to Force the Pause

The easiest way to build this habit is to make your tools slow you down just a little.

Instead of committing directly with a message on the command line, use the editor-based flow:

git commit

Git will open your configured editor (VS Code, Vim, etc.) and give you a blank commit message file. This does two things:

1. You’re forced to stop and think. No more git commit -m "fix" muscle memory.
2. You’re in an editor. That makes it easy to keep your one-note checklist open in a split view.

Suggested setup:

• Left pane: your code diff
• Right pane: your PRE_COMMIT.md (or note) + commit message file

Now your flow becomes:

1. Stage changes.
2. Run git commit.
3. Glance at the checklist and nudge through each point.
4. Write a meaningful subject and description.
5. Save and close to complete the commit.

This tiny bit of friction is a feature, not a bug. You’re buying a few seconds of thinking time in exchange for hours of future debugging.

Treat the Commit Message as a Mini Code Review

Most commit messages are useless:

• fix bug
• update stuff
• changes

They tell you nothing about why the code changed, what you were worried about, or where hidden assumptions live.

Instead, think of each commit message as a short, solo code review:

Subject (50–72 characters):

"Handle empty search queries without calling API"

Body:

• Why this change was needed
• What approach you took
• Assumptions and trade-offs
• Any risk areas or missing tests

Example:

Handle empty search queries without calling API

- Short-circuit search handler when query is empty
- Return empty result set immediately instead of API call
- Assumes empty query should not hit backend (confirmed with PM)
- Trade-off: we no longer log empty queries in analytics
- Missing: edge-case test for whitespace-only queries (TODO)

Notice what this does:

• Future you can instantly see intent.
• Hidden assumptions are documented.
• Known gaps are clearly marked.

Weeks later, when a bug appears (“Why aren’t empty queries in analytics?”), you don’t start from zero. You already know the reasoning and trade-offs.

Baking Best Practices into the Checklist

The best time to enforce coding best practices is right before your code becomes part of history.

Add a “clean code” pass to your one-note ritual:

• Naming

  • Does each function/variable name say what it represents?
  • Are you using domain language, not vague names like data, info, handle?

• Small functions

  • Does any function try to do 3–4 things at once?
  • Can you extract one small, well-named helper?

• Clear responsibilities

  • Is this function/module doing I/O and business logic and formatting?
  • Can you split responsibilities across clearer boundaries?

You don’t need to refactor the entire system on every commit. Just make sure your changes aren’t adding new confusion or complexity.

Think of it as: no new mess.

The Proactive Debugging Pass: Fail in Your Head First

Most developers mentally execute the happy path.

Your pre-commit ritual is a reminder to give equal time to the failure paths:

• What if this returns null?
• What if the API times out or returns malformed data?
• What if the input is massive (10,000 items, not 10)?
• What if this function is called in a tight loop?

Turn that into a quick, proactive debugging pass:

1. Run targeted tests

   • Unit tests for the functions you touched
   • One or two integration tests that exercise the new behavior

2. Add or verify invariants

   • Assertions like: id is never null, array lengths match, states are consistent
   • Guard clauses at the top of functions for invalid inputs

3. Mentally walk failure paths

   • Imagine the DB is down — what does the user see?
   • Imagine the config is missing — do you crash or degrade gracefully?

This takes 30–60 seconds, but it’s eerily effective:

• You spot missing checks before users do.
• You realize which tests you haven’t written yet.
• You harden your code where it’s weakest, not where it’s easiest.

How a Sub-Minute Ritual Compounds to Fewer Bugs

Spending an extra 30–60 seconds per commit may sound like overhead.

In practice, it’s one of the highest-ROI investments you can make in code quality:

• Many teams find that simple checklists + better commits cut defects by 50–80%.
• Bugs that do slip through are easier to trace, because commit messages document assumptions.
• Code stays more maintainable because you’re re-verifying naming, structure, and responsibilities on every commit.

This is compounding in action:

• Today you prevent one null-pointer bug.
• Tomorrow you avoid an N+1 performance issue.
• Next week your clear commit history turns a 3-hour investigation into 10 minutes.

No new tool. No heavyweight process. Just a tiny, consistent pause.

How to Start Today (and Actually Stick With It)

You can implement the One-Note Coding Nudge in 10 minutes:

1. Create your one-note checklist

   • Use the sample above or customize it to your team’s usual bug sources.

2. Switch to editor-based commits

   • Use git config --global core.editor "code --wait" (or your editor of choice).
   • Start using git commit without -m so you always see the editor.

3. Keep the note visible

   • Pin it in your editor.
   • Or keep PRE_COMMIT.md open in a split.

4. Commit to 7 days

   • For one week, use the ritual on every commit.
   • At the end of the week, list bugs you caught because you paused.

You’ll almost certainly find at least one bug or design flaw you would have shipped. That’s your proof it’s working.

Conclusion: The Smallest Possible Process With the Biggest Payoff

You don’t need a new methodology to write better code.

You need a tiny, repeatable pause that asks:

• Did I handle the weird inputs?
• Did I think about errors and failures?
• Is this code clear, small, and readable?
• Did I verify the critical paths?
• Did I explain why this change exists?

The One-Note Coding Nudge is that pause.

It’s one note. One minute. One small habit that, over time, keeps an astonishing number of future bugs out of your repo—and keeps future you from cursing past you in a git blame.

Start with your next commit.