---
name: fetch-diff
description: Fetch PR diff with filtering and line numbers for code review.
allowed-tools:
- Bash(uv run skills fetch-diff:*)
---
# Fetch PR Diff
Fetches a pull request diff, filters out auto-generated files, and adds line numbers for easier review comment placement.
## Usage
```bash
uv run skills fetch-diff <pr_url> [--files <pattern> ...]
```
Examples:
```bash
# Fetch the full diff
uv run skills fetch-diff https://github.com/mlflow/mlflow/pull/123
# Fetch only Python files
uv run skills fetch-diff https://github.com/mlflow/mlflow/pull/123 --files '*.py'
# Fetch only frontend files
uv run skills fetch-diff https://github.com/mlflow/mlflow/pull/123 --files 'mlflow/server/js/*'
# Multiple patterns
uv run skills fetch-diff https://github.com/mlflow/mlflow/pull/123 --files '*.py' '*.ts'
```
Token is auto-detected from `GH_TOKEN` env var or `gh auth token`.
## Output Example
```
diff --git a/path/to/file.py b/path/to/file.py
index abc123..def456 100644
--- a/path/to/file.py
+++ b/path/to/file.py
@@ -10,7 +10,7 @@
10 10 | import os
11 11 | import sys
12 12 | from typing import Optional
13 | -from old_module import OldClass
14 | +from new_module import NewClass
14 15 |
15 16 | def process_data(input_file: str) -> dict:
```
Each line is annotated as `old_line new_line | <marker> content`:
- `-` marker (left number only) -> deleted line, `side=LEFT`, `line=old_line`
- `+` marker (right number only) -> added line, `side=RIGHT`, `line=new_line`
- No marker (both numbers) -> unchanged line, `side=RIGHT`, `line=new_line`
