Agent skill

author-contributions

Identify all files a specific author contributed to on a branch vs its upstream, tracing code through renames. Use when asked who edited what, what code an author contributed, or to audit authorship before a merge. This skill should be run as a subagent — it performs many git operations and returns a concise table.

View SKILL.md on GitHub Repository
Stars 183,714
Forks 39,125

Install this agent skill to your Project

npx add-skill https://github.com/microsoft/vscode/tree/main/.github/skills/author-contributions

SKILL.md

When asked to find all files a specific author contributed to on a branch (compared to main or another upstream), follow this procedure. The goal is to produce a simple table that both humans and LLMs can consume.

Run as a Subagent

This skill involves many sequential git commands. Delegate it to a subagent with a prompt like:

Find every file that author "Full Name" contributed to on branch <branch> compared to <upstream>. Trace contributions through file renames. Return a markdown table with columns: Status (DIRECT or VIA_RENAME), File Path, and Lines (+/-). Include a summary line at the end.

Procedure

1. Identify the author's exact git identity

bash
git log --format="%an <%ae>" <upstream>..<branch> | sort -u

Match the requested person to their exact --author= string. Do not guess — short usernames won't match full display names (resolve via git log or the GitHub MCP get_me tool).

2. Collect all files the author directly committed to

bash
git log --author="<Exact Name>" --format="%H" <upstream>..<branch>

For each commit hash, extract touched files:

bash
git diff-tree --no-commit-id --name-only -r <hash>

Union all results into a set (author_files).

3. Build rename map across the entire branch

For every commit on the branch (not just the author's), extract renames:

bash
git diff-tree --no-commit-id -r -M <hash>

Parse lines with R status to build a map: new_path → {old_paths}.

4. Get the merge diff file list

bash
git diff --name-only <upstream>..<branch>

These are the files that will actually land when the branch merges.

5. Classify each file in the merge diff

For each file in step 4:

  • If it's in author_files → DIRECT
  • Else, walk the rename map transitively (follow chains: current → old → older) and check if any ancestor is in author_files → VIA_RENAME
  • Otherwise → not this author's contribution

6. Get diff stats

bash
git diff --stat <upstream>..<branch> -- <file1> <file2> ...

7. Return the table

Format the result as a markdown table:

| Status | File | +/- |
|--------|------|-----|
| DIRECT | src/vs/foo/bar.ts | +120/-5 |
| VIA_RENAME | src/vs/baz/qux.ts | +300 |
| ... | ... | ... |

**Total: N files, +X/-Y lines**

Important Notes

  • Use Python for the heavy lifting. Shell loops with inline comments break in zsh. Write a temp .py script, run it, then delete it.
  • Author matching is exact. Always run step 1 first. --author does substring matching but you must verify the right person is matched (e.g., don't match "Joshua Smith" when looking for "Josh S."). Use the GitHub MCP get_me tool or git log output to resolve the correct full name.
  • Renames can be multi-hop. A file may have moved contrib/chat/ → agentSessions/ → sessions/. The rename map must be walked transitively.
  • Only report files in the merge diff (step 4). Files the author touched that were later deleted entirely should not appear — they won't land in the upstream.
  • The rename map must include all authors' commits, not just the target author's. Other people often do the rename commits (e.g., bulk refactors/moves).

Example Python Script

python
import subprocess, os

os.chdir('<repo_root>')
UPSTREAM = 'main'
AUTHOR = '<Author Name>'  # Resolve via `git log` or GitHub MCP `get_me`

# Step 2: author's files
commits = subprocess.check_output(
    ['git', 'log', f'--author={AUTHOR}', '--format=%H', f'{UPSTREAM}..HEAD'],
    text=True).strip().split('\n')
author_files = set()
for h in (c for c in commits if c):
    files = subprocess.check_output(
        ['git', 'diff-tree', '--no-commit-id', '--name-only', '-r', h],
        text=True).strip().split('\n')
    author_files.update(f for f in files if f)

# Step 3: rename map from ALL commits
all_commits = subprocess.check_output(
    ['git', 'log', '--format=%H', f'{UPSTREAM}..HEAD'],
    text=True).strip().split('\n')
rename_map = {}  # new_name -> set(old_names)
for h in (c for c in all_commits if c):
    out = subprocess.check_output(
        ['git', 'diff-tree', '--no-commit-id', '-r', '-M', h],
        text=True, timeout=5).strip()
    for line in out.split('\n'):
        if not line:
            continue
        parts = line.split('\t')
        if len(parts) >= 3 and 'R' in parts[0]:
            rename_map.setdefault(parts[2], set()).add(parts[1])

# Step 4: merge diff
diff_files = subprocess.check_output(
    ['git', 'diff', '--name-only', f'{UPSTREAM}..HEAD'],
    text=True).strip().split('\n')

# Step 5: classify
results = []
for f in (x for x in diff_files if x):
    if f in author_files:
        results.append(('DIRECT', f))
    else:
        # walk rename chain
        chain, to_check = set(), [f]
        while to_check:
            cur = to_check.pop()
            if cur in chain:
                continue
            chain.add(cur)
            to_check.extend(rename_map.get(cur, []))
        chain.discard(f)
        if chain & author_files:
            results.append(('VIA_RENAME', f))

# Step 6: stats
if results:
    stat = subprocess.check_output(
        ['git', 'diff', '--stat', f'{UPSTREAM}..HEAD', '--'] +
        [f for _, f in results], text=True)
    print(stat)

# Step 7: table
for kind, f in sorted(results, key=lambda x: x[1]):
    print(f'| {kind:12s} | {f} |')
print(f'\nTotal: {len(results)} files')

Alternative Script

After following the process above, run this script to cross-check files touched by an author against the branch diff. You can do this both with an without src/vs/sessions.

AUTHOR=""

# 1. Find commits by author on this branch (not on main)
git log main...HEAD --author="$AUTHOR" --format="%H"

# 2. Get unique files touched across all those commits, excluding src/vs/sessions/
git log main...HEAD --author="$AUTHOR" --format="%H" \
  | xargs -I{} git diff-tree --no-commit-id -r --name-only {} \
  | sort -u \
  | grep -v '^src/vs/sessions/'

# 3. Cross-reference with branch diff to keep only files still changed vs main
git log main...HEAD --author="$AUTHOR" --format="%H" \
  | xargs -I{} git diff-tree --no-commit-id -r --name-only {} \
  | sort -u \
  | grep -v '^src/vs/sessions/' \
  | while read f; do git diff main...HEAD --name-only -- "$f" 2>/dev/null; done \
  | sort -u

Recommended Agent Skills

Expand your agent's capabilities with these related and highly-rated skills.

microsoft/vscode

component-fixtures

Use when creating or updating component fixtures for screenshot testing, or when designing UI components to be fixture-friendly. Covers fixture file structure, theming, service setup, CSS scoping, async rendering, and common pitfalls.

183,714 39,125
Explore
microsoft/vscode

memory-leak-audit

Audit code for memory leaks and disposable issues. Use when reviewing event listeners, DOM handlers, lifecycle callbacks, or fixing leak reports. Covers addDisposableListener, Event.once, MutableDisposable, DisposableStore, and onWillDispose patterns.

183,714 39,125
Explore
microsoft/vscode

fix-ci-failures

Investigate and fix CI failures on a pull request. Use when CI checks fail on a PR branch — covers finding the PR, identifying failed checks, downloading logs and artifacts, extracting the failure cause, and iterating on a fix. Requires the `gh` CLI.

183,714 39,125
Explore
microsoft/vscode

azure-pipelines

Use when validating Azure DevOps pipeline changes for the VS Code build. Covers queueing builds, checking build status, viewing logs, and iterating on pipeline YAML changes without waiting for full CI runs.

183,714 39,125
Explore
microsoft/vscode

add-policy

Use when adding, modifying, or reviewing VS Code configuration policies. Covers the full policy lifecycle from registration to export to platform-specific artifacts. Run on ANY change that adds a `policy:` field to a configuration property.

183,714 39,125
Explore
microsoft/vscode

chat-customizations-editor

Use when working on the Chat Customizations editor — the management UI for agents, skills, instructions, hooks, prompts, MCP servers, and plugins.

183,714 39,125
Explore

Didn't find tool you were looking for?

Be as detailed as possible for better results