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
| 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 git log --author = "
" --format = "%H" < upstream .. < branch
For each commit hash, extract touched files: 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: 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 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 git diff --stat < upstream
.. < branch
-- < file 1
< file 2
.. . 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 import subprocess , os os . chdir ( '
' ) UPSTREAM = 'main' AUTHOR = ' '
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