Review Code using an LLM

code_review.md

Please perform a comprehensive code review of this diff file. Analyze the changes for:

1. Potential bugs, edge cases, or logic errors
2. Security vulnerabilities or performance issues
3. Adherence to best practices and design patterns
4. Code readability and maintainability
5. Completeness of implementation
6. Suggestions for improvements or alternative approaches

For each issue found, please explain:

• The specific location in the code
• Why it's problematic
• A recommended solution

The diff includes commit messages at the top for context.

review_code.fish

function review_code --description "Review GitHub PRs or jj commits with LLM"
    argparse 'p/pr=' 'c/commits=' 'o/output=' 'm/model=' h/help -- $argv
    or return 1

    if set -q _flag_help
        echo "Usage: review-code [OPTIONS]"
        echo ""
        echo "Options:"
        echo "  -p, --pr NUMBER         Review GitHub PR by number"
        echo "  -c, --commits BASE..HEAD Review jj commits (e.g., abc123..def456)"
        echo "  -o, --output FILE       Output file (default: auto-generated)"
        echo "  -m, --model MODEL       LLM model to use (default: system default)"
        echo "  -h, --help              Show this help"
        echo ""
        echo "Examples:"
        echo "  review-code --pr 86"
        echo "  review-code --commits abc123..def456"
        echo "  review-code --pr 86 --output my_review.md"
        echo "  review-code --pr 86 --model openrouter/openai/gpt-5.1"
        return 0
    end

    # Validate mutually exclusive options
    if set -q _flag_pr; and set -q _flag_commits
        echo "Error: Cannot use both --pr and --commits" >&2
        return 1
    end

    if not set -q _flag_pr; and not set -q _flag_commits
        echo "Error: Must specify either --pr or --commits" >&2
        echo "Run 'review-code --help' for usage" >&2
        return 1
    end

    # Setup directories
    set review_dir dev_tools/reviews
    mkdir -p $review_dir

    # Ensure review directory exists and is ignored
    set gitignore_path .gitignore
    set ignore_entry (string replace $HOME '~' -- $review_dir)
    if not grep -q "^$ignore_entry\$" $gitignore_path 2>/dev/null
        echo $ignore_entry >>$gitignore_path
    end

    # Generate filenames
    if set -q _flag_pr
        set pr_num $_flag_pr
        set diff_file $review_dir/pr-$pr_num.diff
        set output_file (set -q _flag_output && echo $_flag_output || echo $review_dir/comments_pr_$pr_num.md)
    else
        set commits $_flag_commits
        set safe_name (string replace -a '.' '_' -- $commits)
        set diff_file $review_dir/commits-$safe_name.diff
        set output_file (set -q _flag_output && echo $_flag_output || echo $review_dir/comments_commits_$safe_name.md)
    end

    # Fetch/generate diff with commit messages
    if set -q _flag_pr
        echo "Fetching PR #$pr_num..."

        # Check if gh CLI is available
        if not command -v gh &>/dev/null
            echo "Error: GitHub CLI (gh) not found. Install with: brew install gh" >&2
            return 1
        end

        # Fetch commit messages and diff
        echo "=== Commit Messages ===" >$diff_file
        gh pr view $pr_num --json commits --jq '.commits[] | "commit \(.oid)\nAuthor: \(.authors[0].name) <\(.authors[0].email)>\nDate: \(.committedDate)\n\n\(.messageHeadline)\n\(.messageBody)\n"' >>$diff_file 2>/dev/null
        or begin
            echo "Warning: Could not fetch commit messages" >&2
        end

        echo -e "\n=== Diff ===" >>$diff_file
        gh pr diff $pr_num >>$diff_file
        or begin
            echo "Error: Failed to fetch PR diff" >&2
            return 1
        end

    else if set -q _flag_commits
        echo "Generating diff for commits: $commits..."

        # Parse base and head commits
        set parts (string split '..' -- $commits)
        if test (count $parts) -ne 2
            echo "Error: Commits must be in format BASE..HEAD" >&2
            return 1
        end

        set base_commit $parts[1]
        set head_commit $parts[2]

        # Get commit messages
        echo "=== Commit Messages ===" >$diff_file
        jj log -r "$base_commit::$head_commit" --no-graph -T 'concat(
            "commit ", commit_id, "\n",
            "Author: ", author.name(), " <", author.email(), ">\n",
            "Date: ", author.timestamp(), "\n\n",
            description, "\n\n"
        )' >>$diff_file 2>/dev/null
        or begin
            echo "Warning: Could not fetch commit messages" >&2
        end

        # Generate diff
        echo -e "\n=== Diff ===" >>$diff_file
        jj diff --git --color=never -r "$base_commit::$head_commit" >>$diff_file
        or begin
            echo "Error: Failed to generate diff" >&2
            return 1
        end
    end

    echo "Diff saved to: $diff_file"
    echo "Running LLM review..."

    # Run LLM review
    set prompt_file ~/src/unravel/ai-assisted-coding/v1/prompts/code_review.md
    set code_review_prompt (grep -v '^[[:space:]]*#' $prompt_file | cat -s)
    if test -f $prompt_file
        if set -q _flag_model
            cat $diff_file | llm -m $_flag_model "$code_review_prompt" | tee $output_file
        else
            cat $diff_file | llm "$code_review_prompt" | tee $output_file
        end
        echo "Review completed! Saved to: $output_file"
        echo ""
        echo "Files created:"
        echo "  - Diff: $diff_file"
        echo "  - Review: $output_file"
    else
        echo "Error: Prompt file $prompt_file not found" >&2
        exit 1
    end
end