PR Reference Generation Skill
Overview
Queries git for commit metadata and diff output, then produces a structured XML document. Both bash and PowerShell implementations are provided.
Use cases:
- PR description generation from commit history
- Code review preparation with structured diff context
- Work item discovery by analyzing branch changes
- Security analysis of modified files
After successful generation, include a file link to the absolute path of the XML output in the response.
Prerequisites
The repository must have at least one commit diverging from the base branch.
| Platform | Runtime |
|---|---|
| macOS / Linux | Bash (pre-installed) |
| Windows | PowerShell 7+ (pwsh) |
| Cross-platform | PowerShell 7+ (pwsh) |
Quick Start
Run the following command to generate a PR reference with default settings (compares against origin/main):
scripts/generate.sh
scripts/generate.sh --base-branch auto --merge-base --exclude-ext yml,jsonscripts/generate.ps1
scripts/generate.ps1 -BaseBranch auto -MergeBase -ExcludeExt yml,jsonOutput saves to .copilot-tracking/pr/pr-reference.xml by default.
Parameters Reference
| Parameter | Flag (bash) | Flag (PowerShell) | Default | Description |
|---|---|---|---|---|
| Base branch | --base-branch | -BaseBranch | origin/main (bash) / main (PowerShell) | Target branch for comparison. Use auto to detect remote default. |
| Merge base | --merge-base | -MergeBase | false | Use git merge-base for three-way comparison |
| Exclude markdown | --no-md-diff | -ExcludeMarkdownDiff | false | Exclude markdown files (*.md) from the diff |
| Exclude extensions | --exclude-ext | -ExcludeExt | (none) | Comma-separated extensions to exclude (e.g., yml,yaml,json,png) |
| Exclude paths | --exclude-path | -ExcludePath | (none) | Comma-separated path prefixes to exclude (e.g., docs/,.github/) |
| Output path | --output | -OutputPath | .copilot-tracking/pr/pr-reference.xml | Custom output file path |
Both defaults resolve to the same remote comparison. The PowerShell script automatically resolves origin/<branch> when a bare branch name is provided.
Additional Scripts Reference
After generating the PR reference, use these utility scripts to query the XML.
List Changed Files
Run the list script to extract file paths from the diff:
scripts/list-changed-files.sh # all changed files
scripts/list-changed-files.sh --type added # filter by single type
scripts/list-changed-files.sh --type added,modified,renamed # filter by multiple types
scripts/list-changed-files.sh --exclude-type deleted # exclude specific types
scripts/list-changed-files.sh --format markdown # output as markdown tablescripts/list-changed-files.ps1 # all changed files
scripts/list-changed-files.ps1 -Type Added # filter by single type
scripts/list-changed-files.ps1 -Type Added,Modified,Renamed # filter by multiple types
scripts/list-changed-files.ps1 -ExcludeType Deleted # exclude specific types
scripts/list-changed-files.ps1 -Format Json # output as JSON| Parameter | Flag (bash) | Flag (PowerShell) | Default | Description |
|---|---|---|---|---|
| Input path | --input, -i | -InputPath | (auto) | Path to pr-reference.xml |
| Type filter | --type, -t | -Type | all | Change types to include (comma-separated: added, modified, etc.) |
| Exclude type | --exclude-type | -ExcludeType | (none) | Change types to exclude. Mutually exclusive with --type (non-all) |
| Format | --format, -f | -Format | plain | Output format: plain, json, or markdown |
Read Diff Content
Run the read script to inspect diff content with chunking for large diffs:
scripts/read-diff.sh --info # chunk info (count, line ranges)
scripts/read-diff.sh --chunk 1 # read a specific chunk
scripts/read-diff.sh --file src/main.ts # extract diff for one file
scripts/read-diff.sh --summary # file stats summaryscripts/read-diff.ps1 -Info # chunk info
scripts/read-diff.ps1 -Chunk 1 # read a specific chunk
scripts/read-diff.ps1 -File "src/main.ts" # extract diff for one fileOutput Format
The generated XML wraps commit metadata and unified diff output in a <commit_history> root element. See the reference guide for the complete XML schema, element reference, output path variations, and workflow integration patterns.
Troubleshooting
| Symptom | Cause | Resolution |
|---|---|---|
| "No commits found" or empty XML | No diverging commits from base branch | Verify the branch has commits ahead of the base with git log base..HEAD |
| "Branch not found" error | Base branch ref missing locally | Run git fetch origin to update remote tracking refs |
| "git: command not found" | git is not on PATH | Install git or verify PATH includes the git binary directory |
*🤖 Crafted with precision by ✨Copilot following brilliant human instruction, then carefully refined by our team of discerning human reviewers.*