git-prevent-out-of-sync-commit

#!/bin/bash

# Git hook to prevent operations when branch is behind remote
# Place in .git/hooks/pre-push or pre-commit

# Colors for output
RED='\033[0;31m'
YELLOW='\033[1;33m'
NC='\033[0m' # No Color

# Get the current branch name
current_branch=$(git branch --show-current)

if [ -z "$current_branch" ]; then
    echo -e "${RED}Error: Not on any branch (detached HEAD state)${NC}"
    exit 1
fi

# Get the remote tracking branch
remote_branch=$(git rev-parse --abbrev-ref --symbolic-full-name "@{u}" 2>/dev/null)

if [ -z "$remote_branch" ]; then
    # No remote tracking branch - allow the operation
    exit 0
fi

# Fetch the latest changes from remote
git fetch --quiet 2>/dev/null

# Count commits behind
commits_behind=$(git rev-list --count HEAD.."$remote_branch" 2>/dev/null)

if [ -z "$commits_behind" ]; then
    # If we can't determine, allow the operation
    exit 0
fi

# Check if branch is behind remote
if [ "$commits_behind" -gt 0 ]; then
    echo -e "${RED}✗ ERROR: Branch '$current_branch' is behind '$remote_branch' by $commits_behind commit(s)${NC}"
    echo ""
    echo "Missing commits from remote:"
    git log --oneline --decorate HEAD.."$remote_branch"
    echo ""
    echo -e "${YELLOW}Please pull the latest changes first:${NC}"
    echo "  git pull"
    echo ""
    exit 1
fi

# Branch is not behind - allow the operation
exit 0