How to review a pull request on GitHub as a PM

Alex Tutor

Review day for #134. Before you open a single file: what exactly are you reviewing for?

You

Not the code. The behaviour, I guess?

Alex Tutor

The change as a customer will meet it. Does it do what the issue asked? Does the copy read right? Does it do anything the issue didn't ask for? What happens in the cases nobody wrote down?

Daniel

And leave the code to engineers: naming, structure, performance, which pattern I should have used. Oscar has that covered. He approved an hour ago.

Alex Tutor

Reviews on #134 so far

Oscar
Approved these changes: the code is fine

You

So my review answers "is this the right change for customers?", not "is this good code?"

Alex Tutor

Exactly. And if something in the code does look odd to you, ask a question. Don't give instructions about things you can't judge.

Alex Tutor

Question 1

Which of these belong in Sofia's review of #134? Select all that apply.

Choose all that applyWhether the fix does what issue #131 describesWhether a function in the component has a clear nameThe wording of the hint customers will seeWhether a different library would be fasterWhat happens when a customer empties the cartChanges the issue never asked for

Alex Tutor

Start where customers will: on the preview. Follow Daniel's "How to test" first, then try what he didn't write down.

You

Steps one to three work on my phone. I change quantities, the button stays green. I remove everything, it turns grey with a hint: "Cart is empty. Add items to checkout."

Alex Tutor

Now the edge cases: the paths off the happy route. What else can a customer do to a cart?

You

Remove items one by one with the minus button instead of the bin. Apply a promo code, then change a quantity. Open the cart in two tabs and edit it in both.

Daniel

The two tabs one is evil. I love it.

You

All of them work. Only the hint bothers me: "Add items to checkout" reads like an error message.

Alex Tutor

Question 2

Which of these is an edge case worth trying on the preview of #134, beyond Daniel's "How to test" steps?

Choose one answerChecking that the CatChow logo still loads on the home pageApplying a promo code, then changing a quantity in the cartReading the new test file line by lineSwitching the site language on the delivery page

Alex Tutor

Now Files changed. You don't have to read every file. As of 2026 each file has a Viewed checkbox: tick the ones you've looked at or left to others, and they fold away.

You

The component and the test are Oscar's. That leaves copy/cart.json and styles/checkout.css.

Alex Tutor

Hover over a line in the diff, and a blue + appears. Click it, or drag across several lines, and a comment box opens right under the line.

The box has two buttons. Add single comment posts right away. Start a review keeps the comment as pending, so you can add more and send them all together with a verdict.

Daniel

Please batch. Five single comments are five pings in the middle of my work. One review is one ping with your whole thought in it.

Alex Tutor

Until you submit, the comments are marked Pending, and only you can see them.

Alex Tutor

Question 3

Sofia starts a review and leaves three comments, each marked Pending. Daniel can already read them.

TrueFalse

Alex Tutor

`copy/cart.json` in #134

   "cartTitle": "Your cart",
+  "checkoutDisabledHint": "Cart is empty. Add items to checkout.",
   "promoCodeLabel": "Promo code"

One added line: the hint shown under the grey button.

You

Also, "checkout" is the noun, "check out" the verb. So it's wrong as well as cold.

Alex Tutor

Then don't describe the fix, write it. The comment toolbar has a button for a suggested change (as of 2026, a small icon with a plus and a minus). It inserts a suggestion block with the current line, ready to edit.

Alex Tutor

Daniel

On my side it shows as a mini-diff with a Commit suggestion button. One click, and your line becomes a commit on my branch, with you credited as co-author.

Alex Tutor

Keep suggestions for small, exact fixes: copy, a number, a link. For anything bigger, describe the problem and let the author pick the solution.

Alex Tutor

Question 4

Put Sofia's steps for suggesting new wording in order.

Tap an item, then tap where it should go. You can also drag or use the arrows.

Alex Tutor

You

Green to orange. Issue #131 says nothing about colour, and neither does the description.

Daniel

Guilty again. I was in that file anyway, and orange pops more. Admit it.

Alex Tutor

Maybe it does. But it's the main button of the whole shop, changed for every customer, inside a bug fix nobody will read as a redesign. If orders drop next week, nobody will know where to look.

You

And it deserves a proper test: orange against green, as an A/B test, with its own issue.

Alex Tutor

That's the scope check: compare the diff with the issue and the description. Anything extra gets a question, never a silent approval.

Alex Tutor

Question 5

Why shouldn't the colour change ship inside #134?

Choose one answerIt changes what every customer sees, isn't part of #131 or the description, and deserves its own decision and testGit can't merge style files together with code filesOnly designers are allowed to edit styles on GitHubOrange buttons break GitHub's accessibility checks

Alex Tutor

Now write the comment on that line. Remember who reads it: a colleague who spent three days on this and will read your review at six in the evening.

A few habits help. Comment on the change, not the person. Say why, not only what. Ask when you're unsure. Mark small things as optional. And say what's good.

Daniel

"Why did you do this?" and "What's the reason for the colour change?" ask the same thing. Only one of them sounds like an interrogation.

You

So: "The colour change isn't part of #131, and it affects every customer. Could we move it to its own issue and test it there?"

Alex Tutor

That's the one. Specific, with a reason and a way forward.

Alex Tutor

Question 6

Which of these review comments follow the habits above? Select all that apply.

Choose all that apply"Why would you make it orange??""Optional: 'Your cart is empty' might read friendlier than 'Cart is empty'.""This is wrong.""The hint shows up on the preview when the cart is empty. Exactly what #131 needed, nice.""What happens if a promo code expires while the cart is open? I couldn't test that on the preview."

Alex Tutor

Your comments are pending. To send them, use the review button at the top of Files changed: as of 2026 it says Submit review (older layouts say Review changes). It opens a box for a summary and three options.

Comment: feedback without a verdict. Approve: this can be merged. Request changes: something must change before it's merged.

Daniel

People also write "LGTM" in approvals: "looks good to me". Fine, as long as it's true. The rudest review is an LGTM on a pull request nobody opened.

You

And Start a review versus Add single comment? Where does that fit?

Alex Tutor

That comes earlier in the flow. Those two decide whether a comment waits for your verdict or goes out alone. The verdict itself is always one of these three.

Alex Tutor

Question 7

Match each situation with the button or option Sofia should use.

Tap an answer, then tap the row it belongs to. You can also drag.

You will leave several line comments and want to send them together
The preview works, the copy is right, nothing extra is in the diff
The fix works, but the pull request also changes the price of delivery
You only have questions and no verdict yet

Answers left to place

You

The copy is a small fix, but the colour is a real blocker for me. So: Request changes?

Alex Tutor

Yes, as long as the summary says exactly what blocks and why. Don't request changes over a comma, and don't approve while hoping someone else catches the colour.

Daniel

Request changes isn't rude. It's precise. I'd rather know what blocks the merge than guess from a pile of comments.

Alex Tutor

Write the summary now. It's the first thing Daniel reads, above your line comments.

Alex Tutor

Question 8Short answer · AI-checked task

Write the summary for Sofia's Request changes review of #134 (2–4 sentences). Her line comments: a suggestion for the hint copy in copy/cart.json, and a note that the colour change in styles/checkout.css isn't part of #131. The preview worked in every case she tried.

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Alex Tutor

You press Submit review. The merge box at the bottom of Conversation now says "Changes requested", and the merge is blocked, even though Oscar approved.

Alex Tutor

Reviews on #134 after Sofia submits

Oscar
Approved these changes
Sofia
Requested changes: colour change is outside #131

You

Wait, my review blocks it? Daniel said one approval is enough.

Daniel

One approval is required, and a request for changes from anyone with write access holds the merge until that person approves or the review is dismissed. That's our branch protection on main.

Alex Tutor

Branch protection, or a ruleset in newer settings, is a list of rules GitHub enforces on a branch. On main at CatChow: changes only through pull requests, at least one approval, build and test must pass, every conversation resolved, and the branch up to date with main.

Daniel

The last rule appeared after my March adventure with the cookie bar. You'll see it in action tomorrow.

You

And Daniel can't just approve his own pull request?

Daniel

No. GitHub doesn't let authors approve their own pull requests, and only reviews from people with write access count towards the rule.

Alex Tutor

Question 9

CatChow's rules on main require one approval, and both Oscar and Sofia have write access. The checks have passed. Can Daniel merge #134 right now?

Reviews on #134

Oscar
Sofia

Choose one answerYes: one approval is all the rule needsYes, but only with Squash and mergeNo: every requested reviewer has to approve, whatever they saidNo: Sofia's request for changes blocks the merge until Sofia approves or that review is dismissed

Alex Tutor

An hour later. Daniel clicked Commit suggestion on the hint, put the green back in a second commit and replied to both of your comments.

Alex Tutor

fix/checkout-button after the reviewTwo new commits on the branch: c2d7f90 applies Sofia's suggestion, f7a2b61 restores the green button. main hasn't changed.

f02a6d4Update FAQ answers
3a9d1c4Reproduce bug in a test
8be2f70Add cat treats bundle
b7e4a05Re-enable button after cart edits
6f2c8a1Raise free-delivery threshold to 1000 UAH (#133)
a7d93e4Rewrite delivery page copy (#132)main
c2d7f90Update checkout hint copy
f7a2b61Restore checkout button colourfix/checkout-button

Daniel

I typed the message for your suggestion myself: "Update checkout hint copy". GitHub lists you as co-author on that commit. Your first line of code, sort of.

You

His reply under the colour: "Fair. Orange moved to #135, let's test it properly." And he clicked the arrows next to my name to re-request my review.

Alex Tutor

Now close the loop. Each comment thread has a Resolve conversation button, and CatChow's rules block the merge while any thread is open. Here, whoever opened a thread resolves it once satisfied.

You

My line is in, the green is back. Resolving both threads, and this time: Approve.

Alex Tutor

One more pull request for you, start to finish. #154, "Add gift note to checkout", answers issue #139: customers asked to add a note to orders they send as gifts. Oscar has approved the code; the rest is yours.

You

Issue first, then the description, then the preview, then the diff.

Alex Tutor

Good order. Then write the review as you would send it: the line comments, a suggestion where it fits, and a verdict with a summary.

Alex Tutor

Question 10Case · AI-checked task

Write your review of pull request #154: line comments (with a suggestion where it fits), a verdict and a summary.

Issue #139 "Let customers add a gift note" asks for an optional field at checkout, up to 150 characters, printed on the packing slip and not shown on the invoice.

Pull request #154 "Add gift note to checkout", main ← feature/gift-note. Description: adds an optional gift note at checkout, printed on the packing slip; Closes #139. All checks passed; Oscar approved the code.

Files changed (excerpts):

# copy/checkout.json
+  "giftNoteLabel": "Gift mesage (optional)",
+  "giftNotePlaceholder": "A few words for the lucky cat's human",

# components/GiftNote.tsx
+  const MAX_LENGTH = 500;

# config/delivery.json
-  "defaultMethod": "courier",
+  "defaultMethod": "pickup",

On the preview: the note prints on the packing slip. It also appears on the invoice PDF. An emoji in the note shows as an empty box on the packing slip.

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Next lesson: every icon and colour you've seen this week, and a few you haven't, read at a glance.

Daniel

And tomorrow morning I merge #134. Well, as soon as the merge box stops asking me for one more thing.

Alex Tutor

That’s the lesson. You answered every task — nicely done.

Next lesson: Icons and colours: what every state means