hunk-review

name	hunk-review
description	This skill should be used when the user asks to "review code with hunk", "start a hunk review session", "add comments to a hunk diff", "annotate a diff with hunk", "use hunk for code review", or when the user mentions the `hunkdiff` CLI tool. Provides structured guidance for interacting with live Hunk diff review sessions via the daemon CLI.

Hunk Review

Adapted from modem-dev/hunk — MIT License

Overview

Hunk is an interactive terminal diff viewer designed for reviewing code changes, particularly AI-generated ones. This skill controls live Hunk review sessions through the daemon CLI (hunk session, hunk comment). Hunk itself runs as an interactive TUI — do not launch it directly; interact with an already-running session instead.

Installation:

npm i -g hunkdiff

Prerequisite: A Hunk session must already be running (hunk diff, hunk show, or hunk difftool).

---

Workflow

Follow this structured sequence for every review:

1. Discover sessions — identify available sessions and their repository roots
2. Inspect structure — understand files and hunks without loading full diffs
3. Navigate — move to the relevant file or hunk before commenting
4. Reload (if needed) — update session content when the diff changes
5. Comment — annotate specific hunks with focused, high-value notes

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Primary Commands

1. List Sessions

hunk session list

Returns all active sessions. Note the session ID or repository path — both can be used to target sessions in subsequent commands.

Most session commands accept either:

• --repo <path> — match by repository root directory
• <session-id> — explicit session identifier

2. Inspect Session Structure

hunk session review --json

Returns the full file and hunk structure as JSON without loading raw patch text. Use this to understand the shape of the diff before navigating.

Add --include-patch only when examining actual diff content is essential:

hunk session review --json --include-patch

3. Navigate to a Location

Absolute navigation requires --file plus exactly one position target. Hunk indices are zero-based — the first hunk in a file is --hunk 0.

# Jump to a specific hunk index
hunk session navigate --file src/main.py --hunk 2

# Jump to a line in the new version
hunk session navigate --file src/main.py --new-line 42

# Jump to a line in the original version
hunk session navigate --file src/main.py --old-line 17

Relative navigation moves between already-annotated hunks:

hunk session navigate --next-comment
hunk session navigate --prev-comment

Always navigate before adding a comment — this ensures the user sees the relevant code in the Hunk UI at the time the annotation appears.

4. Reload Session Content

Swap the diff content of a running session:

hunk session reload --repo . -- <command>

Note: Reloading replaces the session's diff content. Any comments attached to the previous diff are not preserved — re-apply them after reload using hunk comment apply.

Always include -- before the nested command so its flags are not parsed by Hunk:

# Reload with the latest git diff
hunk session reload --repo . -- git diff HEAD

# Reload with a specific commit
hunk session reload --repo . -- git show abc1234

5. Add Comments

Single comment:

hunk comment add --file src/main.py --hunk 2 "Clarify the intent of this guard clause."

Batch comments (preferred for multiple annotations):

Pipe a JSON array to comment apply via stdin:

hunk comment apply --repo . <<'EOF'
[
  {
    "file": "src/auth.ts",
    "hunk": 1,
    "body": "This token is never invalidated on logout — potential session fixation risk."
  },
  {
    "file": "src/auth.ts",
    "hunk": 3,
    "body": "Prefer `crypto.timingSafeEqual` to avoid timing attacks."
  }
]
EOF

---

Review Best Practices

Prioritise Clarity Over Coverage

Avoid annotating every change. Focus on:

• Intent — is the purpose of the change clear?
• Structure — does the new code fit the existing architecture?
• Risk — are there security, correctness, or performance concerns?
• Follow-ups — what should be addressed before merging?

Work in Narrative Order

Navigate through the diff in the order a reviewer would read it — typically top to bottom within each file, critical files first — rather than strict alphabetical file order.

Batch Where Possible

Prepare all comments for a file or section before calling comment apply. Batching reduces CLI round-trips and produces a coherent annotation set.

Minimal Patch Loading

Do not call --include-patch unless examining the actual diff text is necessary. The JSON structure from hunk session review --json is sufficient for navigation and batch-comment planning in most cases.

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Common Session Patterns

Quick Annotation of a Git Diff

# Start Hunk (user runs this in a separate terminal)
hunk diff HEAD~1

# In this session: list and inspect
hunk session list
hunk session review --json

# Navigate and annotate
hunk session navigate --file src/api.py --hunk 0
hunk comment add --file src/api.py --hunk 0 "Missing input validation before DB write."

Review a PR Locally

# Fetch PR diff and load into Hunk (user runs this)
gh pr diff 42 | hunk diff -

# Reload after new commits are pushed
hunk session reload --repo . -- gh pr diff 42

Full Batch Review

# Inspect structure
hunk session review --json | jq '.files[].name'

# Prepare comments, then apply all at once
hunk comment apply --repo . < review-comments.json

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Troubleshooting

Symptom	Likely Cause	Fix
no session found	No Hunk session running	Start Hunk in a separate terminal first
Navigation has no effect	Wrong --file path	Check exact path with hunk session review --json
-- missing error	Nested command flags parsed by Hunk	Add -- before the nested command
Comments not visible	Session was reloaded after commenting	Re-apply comments after reload