A bash script that creates clean, markdown-formatted summaries of commits between main and your current branch - perfect for pull request descriptions and release notes.

README.md

Git Branch Summary Generator

A bash script that creates clean, markdown-formatted summaries of commits between main and your current branch - perfect for pull request descriptions and release notes.

Setup & Usage

1. Save as summary-git in your ~/bin or another directory in your $PATH
2. Make executable: chmod +x summary-git
3. Run from any git repository: summary-git

Features

• Smart commit processing: Strips semantic commit prefixes (feat:, fix:, etc.) and capitalizes messages
• Intelligent list handling: Processes both markdown lists and inline - separated items
• Clean formatting: Word-wraps at 76 characters with proper indentation
• Ready-to-use output: Generates markdown that's perfect for GitHub PR descriptions

Example Output

## Summary based on commit messages

- Implement JWT authentication
  - Add login endpoint
  - Add token validation middleware
  - Update user model with tokens
- Resolve API timeout issues
  Updated connection pooling and added retry logic

summary-git.sh

#!/bin/bash

echo "## Summary based on commit messages"
echo ""

# Function to process and output list items
process_list_content() {
    local content="$1"

    # Collapse all whitespace and newlines into single spaces first
    content=$(echo "$content" | tr '\n' ' ' | sed 's/[[:space:]]\+/ /g' | sed 's/^[[:space:]]*//;s/[[:space:]]*$//')

    # Check if content has inline list separators (space-dash-space)
    if [[ "$content" =~ [[:space:]]-[[:space:]] ]]; then
        # Split on " - " and process each item as a separate list item
        echo "$content" | sed 's/ - /\n- /g' | while IFS= read -r item; do
            if [[ -n "$item" && "$item" != " " ]]; then
                item=$(echo "$item" | sed 's/^[[:space:]]*//;s/[[:space:]]*$//')
                if [[ -n "$item" ]]; then
                    # Add leading dash if it doesn't start with one
                    if [[ ! "$item" =~ ^- ]]; then
                        item="- $item"
                    fi
                    echo "  $item" | fold -s -w 76 | sed 's/^/  /'
                fi
            fi
        done
    else
        # Process line by line for regular list items
        echo "$content" | while IFS= read -r line; do
            if [[ -n "$line" && "$line" != " " ]]; then
                line=$(echo "$line" | sed 's/^[[:space:]]*//;s/[[:space:]]*$//')
                if [[ -n "$line" ]]; then
                    # Check if this line starts with list markers
                    if [[ "$line" =~ ^[[:space:]]*[*-][[:space:]] ]]; then
                        echo "  $line" | fold -s -w 76 | sed 's/^/  /'
                    else
                        # Regular text line
                        echo "  $line" | fold -s -w 76 | sed 's/^/  /'
                    fi
                fi
            fi
        done
    fi
}

# Get the git log and process it
git log --pretty=format:"COMMIT_START%s%nBODY_START%b%nCOMMIT_END" --reverse main..HEAD | \
while IFS= read -r line; do
    if [[ $line == COMMIT_START* ]]; then
        # Extract commit message and remove semantic commit prefixes
        message="${line#COMMIT_START}"
        # Remove common semantic commit prefixes (case insensitive)
        message=$(echo "$message" | sed -E 's/^(feat|fix|docs|style|refactor|test|chore|build|ci|perf|revert)(\([^)]*\))?: ?//i')
        # Capitalize first letter
        message="$(echo ${message:0:1} | tr '[:lower:]' '[:upper:]')${message:1}"
        echo "- $message"
        in_body=false
        body_content=""
    elif [[ $line == BODY_START* ]]; then
        body="${line#BODY_START}"
        body_content="$body"
        in_body=true
    elif [[ $line == COMMIT_END ]]; then
        # Process accumulated body content
        if [[ -n "$body_content" && "$body_content" != " " ]]; then
            # Check if it contains list items (either format)
            if [[ "$body_content" =~ [*-][[:space:]] ]] || [[ "$body_content" =~ [[:space:]]-[[:space:]] ]]; then
                process_list_content "$body_content"
            else
                body_content=$(echo "$body_content" | tr '\n' ' ' | sed 's/[[:space:]]\+/ /g' | sed 's/^[[:space:]]*//;s/[[:space:]]*$//')
                if [[ -n "$body_content" ]]; then
                    echo "  $body_content" | fold -s -w 76 | sed 's/^/  /'
                fi
            fi
        fi
        in_body=false
        body_content=""
    elif [[ $in_body == true && -n "$line" && "$line" != " " ]]; then
        # Accumulate body content
        if [[ -n "$body_content" ]]; then
            body_content="$body_content $line"
        else
            body_content="$line"
        fi
    fi
done