# docs: fix missing code highlights in tic-tac-toe tutorial

Five code blocks in the tic-tac-toe tutorial had incorrect highlight ranges — either missing newly-introduced lines or over-highlighting lines already present from a prior step.

| | |
| --- | --- |
| Status | COPILOT-WRITTEN · MERGED |
| Source | github:pmndrs/zustand#3527 |
| Original | https://github.com/pmndrs/zustand/pull/3527 |
| Workspace | Showcase |
| Tags | github, code, docs |

## What it does

**A single-file change to tutorial-tic-tac-toe.md, 10 lines.**

Copilot opened this, so there is no author to ask. 1 file changed across 1 area of pmndrs/zustand, 5 added and 5 removed.

Five code blocks in the tic-tac-toe tutorial had incorrect highlight ranges — either missing newly-introduced lines or over-highlighting lines already present from a prior step.

**Diagram: Where the change landed. Node size is not to scale; the line counts are exact.**

- zustand (1 files, 10 lines) [accent]
- Docs (1 file, 10 lines) [neutral]
- tutorial-tic-tac-toe.md (+5 −5) [bad]
- zustand -> Docs
- Docs -> tutorial-tic-tac-toe.md : heaviest

- **Written by an agent.** Copilot authored this change. The usual review shortcut, asking the person who wrote it, is not available, so everything a reviewer needs has to come from the diff itself.
- **Heaviest file.** docs/learn/guides/tutorial-tic-tac-toe.md, +5 −5, which is 100% of the change.
- **No test changed.** 0 source files changed with no accompanying test edit.
- **Spread.** 1 files, 10 changed lines in total.

## How it works

**The largest single edit is in tutorial-tic-tac-toe.md.**

Quoted verbatim from the diff. This is the biggest hunk by changed lines, which is where a reviewer's attention usually belongs first.

```markdown
@@ -567,7 +567,7 @@ To let the players know when the game is over, you can display text such as `'Wi
 display the winner or draw if the game is over and if the game is ongoing you'll display which
 player's turn is next:
 
-```jsx {6-7,9,21}
+```jsx {6-7,9,20-21,40}
 export default function Board() {
   const xIsNext = useGameStore((state) => state.xIsNext)
   const setXIsNext = useGameStore((state) => state.setXIsNext)
```

_docs/learn/guides/tutorial-tic-tac-toe.md, +5 −5. The largest hunk in the largest file._

## File map

**Every file this change touches, heaviest first.**

Role is inferred from the path and risk from the path and the line count. Neither was read from the code.

| File | Role | Change | Risk |
| --- | --- | --- | --- |
| `docs/learn/guides/tutorial-tic-tac-toe.md` | documentation | modified, +5 −5 | none |

## Receipts

**Where each number above comes from.**

All of it is arithmetic over the file list and the check results, so it can be recomputed from the source.

- **Claim.** Em dash density: 6 occurrences.
  - Evidence: …-toe tutorial had incorrect highlight ranges — either missing newly-introduced lines or ove…
  - Where: description and comments
- **Claim.** Copilot wrote this change.
  - Evidence: copilot-swe-agent
  - Where: commit 63e758f
- **Claim.** 1 files changed, +5 −5.
  - Evidence: docs/learn/guides/tutorial-tic-tac-toe.md (+5 −5)
  - Where: https://github.com/pmndrs/zustand/pull/3527
- **Claim.** tutorial-tic-tac-toe.md carries 100% of the changed lines.
  - Evidence: 10 of 10 changed lines
  - Where: docs/learn/guides/tutorial-tic-tac-toe.md
- **Claim.** It arrived as 1 commit.
  - Evidence: docs: fix missing code highlights in tic-tac-toe tutorial
  - Where: commit 63e758f
- **Claim.** CI reports 0 failing of 30.
  - Evidence: Continuous Releases
  - Where: CI check: Continuous Releases
- **Claim.** The change drew 3 comments.
  - Evidence: [vc]: #KWjOSpTccY586VeNj0ssU4wW2e3wOInASdfSfsl5ObA=:eyJpc01vbm9yZXBvIjp0cnVlLCJ0eXBlIjoiZ2l0aHViIiwicHJvamVjdHMiOlt7Im5hbWUiOiJ6dXN0YW5kLWRl…
  - Where: comment by vercel[bot]

## Merge order

**A reading order for the review, not a deployment plan.**

Ordered by how expensive each part is to get wrong, which is a structural property rather than an informed one.

1. **Then tutorial-tic-tac-toe.md.** The largest single file in the change, +5 −5.
2. **Decide whether a test is needed.** Nothing in this change adds or edits one.

## What this brief could not check

- No language model read this change. Every statement here is computed from file paths, line counts, and CI status, so it describes the shape of the diff and not what the diff means.