A practical checklist for readable pull requests

Disclosure: This article was created or edited with AI assistance. Revised on 13 October 2026 to remove promotional links and unsupported outcome claims. It is educational guidance, not a verified personal case study or a measured result. Examples are illustrative; use only your own documented experience and measurements.

The sections below present options and illustrative examples. Adapt them to the requirements of your project or role; they do not establish a universal rule or promise a result.

Readability alongside correctness

Every junior developer thinks code review is about finding bugs. It's not.

Sure, we catch bugs. But the real purpose of code review is answering one question: "Can someone else understand and maintain this code six months from now?"

That's it. If the answer is yes, the code passes. If the answer is no, it doesn't matter how technically brilliant it is.

Mistake 1: Giant Pull Requests

This is the number one issue. Someone works on a feature for two weeks, then opens a PR with 47 changed files and 2,000+ lines of code.

Nobody is going to review that properly. They'll skim it, approve it, and pray nothing breaks.

One approach: Keep changes focused and agree on a reviewable size with your team. Line counts alone do not determine review quality.

Mistake 2: Meaningless Variable Names

# Bad
d = get_data()
r = process(d)
x = transform(r)

# Good
user_profiles = fetch_user_profiles()
filtered_profiles = remove_inactive(user_profiles)
profile_summaries = generate_summaries(filtered_profiles)

I see this constantly. Single-letter variables, abbreviations nobody understands, names that describe the type instead of the purpose.

Your variable name is documentation. Treat it that way.

Mistake 3: No Error Handling

// Bad: pretending errors don't exist
const data = await fetch('/api/users').then(r => r.json());

// Good: handling the real world
try {
  const response = await fetch('/api/users');
  if (!response.ok) {
    throw new Error(`Failed to fetch users: ${response.status}`);
  }
  const data = await response.json();
} catch (error) {
  logger.error('User fetch failed', { error });
  showErrorToast('Could not load users. Please try again.');
}

Happy path code is easy. Production code handles the unhappy path. Every network call can fail. Every user input can be wrong. Every file might not exist.

If I see a PR with zero error handling, it goes straight back for revision.

Mistake 4: Comments That Explain "What" Instead of "Why"

# Increment counter by 1
counter += 1

# Increment counter after successful verification
counter += 1

Your code should be readable enough to explain WHAT it does. Comments should explain WHY it does it. The business logic, the edge case it handles, the reason for a weird workaround.

An illustrative comment is: "This looks wrong but it's correct. The API returns dates in UTC-5 even when you request UTC. See ticket PROJ-1234."

The comment identifies the behavior and the context a reader should verify.

Mistake 5: Reinventing the Wheel

Before writing any utility function, check if:

1. Your language/framework has a built-in solution
2. Your project already has a library that does this
3. Someone on your team already wrote this

Mistake 6: Mixing Concerns in One Function

# Bad: this function does everything
def process_order(order):
    validate_items(order.items)
    calculate_tax(order)
    apply_discount(order)
    charge_payment(order)
    send_confirmation_email(order)
    update_inventory(order)
    log_analytics(order)

# Good: each function does one thing
def process_order(order):
    validated_order = validate_order(order)
    priced_order = calculate_pricing(validated_order)
    payment_result = process_payment(priced_order)
    finalize_order(priced_order, payment_result)

Consider splitting a function when separate responsibilities have different reasons to change. Length and conjunctions alone are not a reliable test.

Mistake 7: No Tests for Edge Cases

Most developers test the happy path. Order goes through, user logs in, data loads. Great.

But what about:

• Empty arrays?
• Null values?
• Network timeouts?
• User submits the form twice?
• Input has 10,000 characters?

The bugs that make it to production are almost always edge cases. Test them.

1. Small, Focused Changes

One PR, one purpose. "Add user search" or "Fix date parsing bug." Not "Add search, refactor database layer, update styles, and fix that thing from last week."

2. Self-Documenting Code

When I read the code and don't need to ask any questions, that's good code. Clear function names, obvious variable names, logical file structure.

3. Tests That Cover Edge Cases

When I see tests for empty inputs, error states, and boundary conditions, I know the developer thought about production, not just the demo.

4. Clean Git History

Atomic commits with clear messages. Not "fix stuff" or "WIP" or "asdfgh." Each commit should tell a story.

feat: add user search endpoint
test: add integration tests for user search
docs: update API documentation for search endpoint

5. They Reviewed Their Own Code First

You'd be amazed how many issues you can catch by looking at your own diff before submitting. I always review my own PRs before asking anyone else to. It catches typos, leftover debug logs, and "oh wait, I forgot to handle that case."

How to Write Code That's Easy to Review

Here's my checklist before opening a PR:

Before writing:

• [ ] Is the task clear? Do I understand what "done" looks like?
• [ ] Have I checked if similar code exists in the project?

While writing:

• [ ] Are my functions short and focused?
• [ ] Are my variable names descriptive?
• [ ] Am I handling errors properly?
• [ ] Am I writing tests as I go?

Before submitting:

• [ ] Is the PR focused and practical to review?
• [ ] Did I review my own diff?
• [ ] Did I remove debug logs and commented-out code?
• [ ] Does the PR description explain WHAT and WHY?
• [ ] Do all tests pass?

The Takeaway

Code review isn't about gatekeeping. It's about raising the bar for everyone, including yourself. The best way to get better at writing code is to read a lot of other people's code and have other people read yours.

If you're a junior developer, don't fear code reviews. Request them. Ask for brutal honesty. Specific feedback can reveal assumptions and alternatives you have not considered.

And if you're the reviewer, remember: your job isn't to prove you're smarter than the author. Your job is to help them ship better code.