Fix GitHub Issue

When to Use

• You have a GitHub Issue number and want to resolve it from scratch
• Debugging a reported bug with a clear reproduction case
• Picking up an issue from the backlog and implementing the fix
• Fast-track for "good first issue" or well-scoped bug reports

Differentiation from github-issue-triage: This skill fixes issues (code changes, tests, PR). github-issue-triage is for organizing and classifying issues in bulk.

Prerequisites

• GitHub MCP server available (built-in to Copilot CLI)
• Write access to the repository for creating a branch and PR
• gh CLI installed (for branch creation and PR fallback)

Workflow

1. Read the Issue

# Via Copilot MCP (structured data, no token needed):
# Tool: github-mcp-server-issue_read
#   method: "get"
#   owner: "my-org"
#   repo: "my-app"
#   issue_number: 123

# Also read any existing comments for additional context:
# Tool: github-mcp-server-issue_read
#   method: "get_comments"
#   owner: "my-org"
#   repo: "my-app"
#   issue_number: 123

Extract:

• Expected behavior vs actual behavior
• Reproduction steps
• Stack trace or error message (if present)
• Labels (bug/enhancement/docs)

2. Search for the Root Cause

# Search for the symbol, function, or error message mentioned in the issue
git --no-pager grep -n "functionNameFromIssue" -- "*.ts" "*.js"

# If it's an error message, search for where it's generated
git --no-pager grep -rn "the exact error string"

# Recent changes to the affected file
git --no-pager log --oneline -10 -- path/to/file.ts

3. Create a Dedicated Branch

$issueNumber = 123
$shortDesc = "fix-null-check-users-api"
git checkout -b "fix/issue-$issueNumber-$shortDesc"

4. Reproduce the Issue (Write a Failing Test First)

If the project has tests, write the test before fixing:

# Run existing tests to confirm baseline
npm test -- --testPathPattern="users"

# Write a failing test that demonstrates the bug
# (Edit the appropriate test file)

# Confirm test fails
npm test -- --testPathPattern="users" 2>&1 | Select-Object -Last 20

5. Implement the Fix

Make the minimal change to fix the root cause. Avoid unrelated cleanup in this commit.

# Verify tests pass after fix
npm test -- --testPathPattern="users"

# Run broader test suite
npm test

6. Commit with Issue Reference

git add -A
git commit -m "🐛 fix(users): handle null response when user not found

Fixes #123. The /api/users/:id endpoint was throwing a 500 error when the
user ID did not exist instead of returning 404. Added null check before
accessing user.profile."

7. Push and Open a PR

git push -u origin HEAD

# Open PR via gh CLI
gh pr create `
  --title "fix: handle null user in /api/users/:id (closes #123)" `
  --body "## Summary
Fixes #123

## Root Cause
The handler called \`user.profile.name\` without checking if \`user\` existed.

## Fix
Added early return with 404 response when user is not found.

## Testing
- Added unit test \`should return 404 when user not found\`
- All existing tests pass" `
  --base main

Examples

Bug: API Returns 500 Instead of 404

Issue #89: GET /api/posts/999 returns 500 Internal Server Error
Expected: 404 Not Found
Actual: TypeError: Cannot read property 'title' of null

Copilot workflow:

1. issue_read → get full issue context
2. grep -n "Cannot read property" → find where null is accessed
3. Create branch fix/issue-89-null-post
4. Write test: expect(response.status).toBe(404)
5. Fix: add if (!post) return res.status(404).json({ error: 'Post not found' })
6. Commit with Fixes #89
7. Open PR

Enhancement: Add Missing Field to API Response

Issue #102: Missing 'updatedAt' field in /api/users response
Expected: response includes updatedAt timestamp
Actual: field not present

Copilot workflow:

1. issue_read + get_comments → clarify which endpoint and format
2. Search for the serializer/transformer function
3. Add updatedAt field
4. Update API docs/types
5. Commit with Fixes #102

Tips

• Always read comments — the reporter or maintainers often add crucial context after filing
• Label check: if issue is labeled needs-repro, ask for reproduction steps before fixing
• Small PRs fix faster: keep fix PRs minimal — reference the issue for full context
• Use Fixes #N in commit: GitHub will auto-close the issue on merge
• Check for duplicates: search for related issues before starting — search_issues with the error message

See Also

• github-issue-triage — organize/classify issues in bulk
• commit-workflow — craft the commit message
• github-pr-workflow — manage the resulting PR
• Inspired by: awesome-claude-code/resources/slash-commands/fix-github-issue