pr-walkthrough— agent skill

Walks through a PR's changes interactively, explaining one file and one section at a time - like a human would sit and explain their code. Each step requires user to say "next" to continue.

Optional PR number from user input

"$ARGUMENTS"

Argument Handling

• If PR number provided: Use specified PR
• If empty: Use PR for current branch (via gh pr view)

Process

Step 1: Initialize Review Session

Fetch the PR and map all changes into reviewable blocks:

# Get PR number
if [ -n "$ARGUMENTS" ]; then
  PR_NUM="$ARGUMENTS"
else
  PR_NUM=$(gh pr view --json number --jq '.number' 2>/dev/null)
  if [ -z "$PR_NUM" ]; then
    echo "Error: No PR number provided and current branch has no associated PR"
    exit 1
  fi
fi

# Get PR info
PR_INFO=$(gh pr view "$PR_NUM" --json title,author,url,files)
PR_TITLE=$(echo "$PR_INFO" | jq -r '.title')
PR_URL=$(echo "$PR_INFO" | jq -r '.url')

# Get list of changed files
FILES=$(echo "$PR_INFO" | jq -r '.files[]? | .path')

Step 2: Map All Review Blocks

Create a structured map of all changes to review:

1. For each changed file:

• Get the full diff using gh pr diff "$PR_NUM" -- "$FILE_PATH"
• Parse diff into logical sections (functions, classes, imports, etc.)
• Identify the nature of each change (new file, modified function, etc.)

1. Create review structure:

   File 1: path/to/file.py
     - Section 1.1: New imports (lines X-Y)
     - Section 1.2: Modified function_name() (lines A-B)
     - Section 1.3: New class ClassName (lines C-D)
   File 2: path/to/other.py
     - Section 2.1: ...
   ...

1. Display the map:

Show user the complete structure of what will be reviewed, like a table of contents

Step 3: Interactive Walkthrough

For each section in order:

1. Display current context:

   📍 Currently reviewing: File X/Y - Section A/B
   File: path/to/file.py
   Section: Modified function_name() (lines 42-58)

1. Explain at high level:

• What this section does (1-2 sentences)
• Why this change was needed
• How it fits into the PR's overall goal
• Note any important details that will be covered later

1. Show the actual code change:

• Display the relevant diff section
• Highlight key parts without going into deep details yet

1. Wait for user:

• Explicitly state: "Type 'next' when ready to continue, or ask questions about this section"
• DO NOT proceed until user says "next" or asks a clarifying question
• If user asks questions, answer them in depth before moving on

1. Handle user input:

• If user says "next": Move to next section
• If user asks "why...": Explain the reasoning in depth
• If user asks "how...": Explain the implementation details
• If user asks "what if...": Discuss edge cases and alternatives
• If user says "back": Go to previous section
• If user says "skip file": Jump to next file

Step 4: File Transitions

When finishing a file:

1. Provide a brief summary of what changed in that file
2. Explain how it connects to the next file (if relevant)
3. Show progress: "Completed file X/Y"
4. Wait for "next" before starting the next file

Step 5: Review Complete

When all sections are reviewed:

1. Provide a high-level summary of all changes
2. Highlight the key takeaways
3. Ask if user wants to revisit any specific sections

Important Notes

• Never auto-proceed: Always wait for explicit "next" command
• One section at a time: Never explain multiple sections at once
• High-level first: Save implementation details for when user asks
• Be conversational: Explain like you're pair programming
• Track state: Remember which section we're on throughout the conversation
• Handle questions: When user asks questions, go deeper on that specific topic