Generate PR Description

You are tasked with generating a comprehensive pull request description following the repository's standard template.

Usage: /describe_pr $1

If no PR number is provided, identify the PR to describe

• Check if the current branch has an associated PR: gh pr view --json url,number,title,state 2>/dev/null
• If no PR exists for the current branch, or if on main/master, list open PRs: gh pr list --limit 10 --json number,title,headRefName,author
• Ask the user which PR they want to describe

Steps to follow:

1. Read the PR description template:

   • Read the template at .github/pull_request_template.md carefully to understand all sections and requirements

2. Gather comprehensive PR information:

   • Get the full PR diff: gh pr diff {number}
   • If you get an error about no default remote repository, instruct the user to run gh repo set-default and select the appropriate repository
   • Get commit history: gh pr view {number} --json commits
   • Review the base branch: gh pr view {number} --json baseRefName
   • Get PR metadata: gh pr view {number} --json url,title,number,state

3. Analyze the changes thoroughly: (ultrathink about the code changes, their architectural implications, and potential impacts)

   • Read through the entire diff carefully
   • For context, read any files that are referenced but not shown in the diff
   • Understand the purpose and impact of each change
   • Identify user-facing changes vs internal implementation details
   • Look for breaking changes or migration requirements

4. Generate the description:

   • Fill out each section from the template thoroughly:
     • Answer each question/section based on your analysis
     • Be specific about problems solved and changes made
     • Focus on user impact where relevant
     • Include technical details in appropriate sections
     • Write a concise changelog entry
   • Ensure all checklist items are addressed (checked or explained)

5. Save the description:

   • Write the completed description to {number}_description.md (DO NOT COMMIT THIS FILE)
   • Show the user the generated description

6. Update the PR:

   • Update the PR description directly: gh pr edit {number} --body-file {number}_description.md
     • This requires the 'project' GitHub scope. If the command fails you can check the scope with gh auth status.

Important notes:

• Be thorough but concise - descriptions should be scannable
• Focus on the "why" as much as the "what"
• Include any breaking changes or migration notes prominently
• If the PR touches multiple components, organize the description accordingly
• Always attempt to run verification commands when possible
• Clearly communicate which verification steps need manual testing