GitHub PR Review Operation

GitHub CLI (gh) for PR review operations.

Prerequisites

• gh installed
• gh auth login completed

Parsing PR URL

Extract from PR URL https://github.com/OWNER/REPO/pull/NUMBER:

• OWNER: Repository owner
• REPO: Repository name
• NUMBER: PR number

Operations

1. Retrieve PR Information

gh pr view NUMBER --repo OWNER/REPO --json title,body,author,state,baseRefName,headRefName,url

2. Retrieve Diff with Line Numbers

gh pr diff NUMBER --repo OWNER/REPO | awk '
/^@@/ {
  match($0, /-([0-9]+)/, old)
  match($0, /\+([0-9]+)/, new)
  old_line = old[1]
  new_line = new[1]
  print $0
  next
}
/^-/ { printf "L%-4d     | %s\n", old_line++, $0; next }
/^\+/ { printf "     R%-4d| %s\n", new_line++, $0; next }
/^ / { printf "L%-4d R%-4d| %s\n", old_line++, new_line++, $0; next }
{ print }
'

Output example:

@@ -46,15 +46,25 @@ jobs:
L46   R46  |            prompt: |
L49       | -            (deleted line)
     R49  | +            (added line)
L50   R50  |              # Review guidelines

• L{number}: Line number on LEFT (base) side → use with side=LEFT for inline comments
• R{number}: Line number on RIGHT (head) side → use with side=RIGHT for inline comments

3. Retrieve Comments

Issue Comments (comments on the entire PR):

gh api repos/OWNER/REPO/issues/NUMBER/comments --jq '.[] | {id, user: .user.login, created_at, body}'

Review Comments (comments on code lines):

gh api repos/OWNER/REPO/pulls/NUMBER/comments --jq '.[] | {id, user: .user.login, path, line, created_at, body, in_reply_to_id}'

4. Post Comment to PR

gh pr comment NUMBER --repo OWNER/REPO --body "Comment text"

5. Post Inline Comment (Code Line Specific)

First, retrieve the head commit SHA:

gh api repos/OWNER/REPO/pulls/NUMBER --jq '.head.sha'

Single line comment:

gh api repos/OWNER/REPO/pulls/NUMBER/comments \
  --method POST \
  -f body="Comment text" \
  -f commit_id="COMMIT_SHA" \
  -f path="src/example.py" \
  -F line=15 \
  -f side=RIGHT

Multi-line comment (lines 10-15):

gh api repos/OWNER/REPO/pulls/NUMBER/comments \
  --method POST \
  -f body="Comment text" \
  -f commit_id="COMMIT_SHA" \
  -f path="src/example.py" \
  -F line=15 \
  -f side=RIGHT \
  -F start_line=10 \
  -f start_side=RIGHT

Important Notes:

• Use -F (uppercase) for numeric parameters (line, start_line). Using -f will convert them to strings and cause errors.
• side: RIGHT (added lines) or LEFT (deleted lines)

6. Reply to Comment

gh api repos/OWNER/REPO/pulls/NUMBER/comments/COMMENT_ID/replies \
  --method POST \
  -f body="Reply text"

Use the id from retrieved comments as COMMENT_ID.

Important Guidelines

All review comments must be written in Japanese to ensure consistency with team communication and maintain clarity for all team members.

Examples:

• Inline comment: "この行でnullチェックが必要です。"
• Review comment: "コードレビュー完了しました。承認します。"
• Reply: "ご指摘ありがとうございます。修正しました。"

Common Workflow

# 1. Get PR info
PR_NUM=123
OWNER_REPO="owner/repo"
gh pr view $PR_NUM --repo $OWNER_REPO --json title,body

# 2. Get diff with line numbers
gh pr diff $PR_NUM --repo $OWNER_REPO | awk '...' > /tmp/diff.txt

# 3. Get existing comments
gh api repos/$OWNER_REPO/pulls/$PR_NUM/comments > /tmp/comments.json

# 4. Get commit SHA
COMMIT_SHA=$(gh api repos/$OWNER_REPO/pulls/$PR_NUM --jq '.head.sha')

# 5. Post inline comments
gh api repos/$OWNER_REPO/pulls/$PR_NUM/comments \
  --method POST \
  -f body="この部分はnullチェックが必要です。" \
  -f commit_id="$COMMIT_SHA" \
  -f path="src/file.ts" \
  -F line=42 \
  -f side=RIGHT

# 6. Submit review
gh api repos/$OWNER_REPO/pulls/$PR_NUM/reviews \
  --method POST \
  -f body="コードレビュー完了しました。承認します。" \
  -f event="APPROVE" \
  -f commit_id="$COMMIT_SHA"

Troubleshooting

Comment on wrong line: Verify line numbers using the diff output with L/R format. Ensure side parameter matches (LEFT for removed, RIGHT for added).

Reply not threaded: Include all required fields and ensure COMMENT_ID is correct.

Comments not retrieved: Fetch both types - issue comments and review comments are separate endpoints.