Script to rewrite a branch's history

gitrewrite.py

#!/usr/bin/env python3


# Rewrite whole history for a branch

import os
import subprocess
from pathlib import Path

class bcolors:
    HEADER = '\033[95m'
    OKBLUE = '\033[94m'
    OKCYAN = '\033[96m'
    OKGREEN = '\033[92m'
    WARNING = '\033[93m'
    FAIL = '\033[91m'
    ENDC = '\033[0m'
    BOLD = '\033[1m'
    UNDERLINE = '\033[4m'


def get_active_branch_name():
    head_dir = Path(".") / ".git" / "HEAD"
    with head_dir.open("r") as f: content = f.read().splitlines()

    for line in content:
        if line[0:4] == "ref:":
            return line.partition("refs/heads/")[2]

current_branch = get_active_branch_name()

print("Current branch: " + current_branch)

base_branch = input("Branch to reset current branch from: ")

# check if branch exists
# branch_exists_command = "git branch --list " + base_branch
branch_exists_command = "git show-ref --verify refs/heads/" + base_branch

print(bcolors.HEADER + "\n|-----------------------------------------------------------------------------| \n" + bcolors.ENDC)
print("Checking if " + base_branch + " exists...")
print(bcolors.OKCYAN + branch_exists_command + bcolors.ENDC)
branch_exists = os.system(branch_exists_command)

print(bcolors.HEADER + "\n|-----------------------------------------------------------------------------| \n" + bcolors.ENDC)

if (branch_exists != 0):
    print(bcolors.FAIL + base_branch + " does not exists" + bcolors.ENDC)
    print(bcolors.HEADER + "\n|-----------------------------------------------------------------------------| \n" + bcolors.ENDC)
    exit()



new_commit_message = input("New message: ")

reset_command = "git reset $(git merge-base " + base_branch + " " + current_branch + ")"

add_all = "git add --all"

commit_message = "git commit -m '" + new_commit_message + "'"

print(bcolors.HEADER + "\n|-----------------------------------------------------------------------------| \n" + bcolors.ENDC)

print(bcolors.OKCYAN + "Running: " + reset_command + bcolors.ENDC)
os.system(reset_command)

print(bcolors.HEADER + "\n|-----------------------------------------------------------------------------| \n" + bcolors.ENDC)

print(bcolors.OKCYAN + "Running: " + add_all + bcolors.ENDC)
os.system(add_all)

print(bcolors.HEADER + "\n|-----------------------------------------------------------------------------| \n" + bcolors.ENDC)

print(bcolors.OKCYAN + "Running: " + commit_message + bcolors.ENDC)
os.system(commit_message)

print(bcolors.HEADER + "\n|-----------------------------------------------------------------------------| \n" + bcolors.ENDC)

print(bcolors.OKGREEN + "Done. \n" + bcolors.ENDC)

Install

get the script

wget https://gist.githubusercontent.com/alexander-alegre/3bd9864b9018082469101aba97cf88e4/raw/ec70084a8fe5fc1cb57f20378295e23b09c7f7dc/gitrewrite.py

make the script an executable

chmod +x gitrewrite.py

add alias to .bashrc or .zshrc

alias gitrewrite="/PathToWhereYouSavedIt/gitrewrite.py"

source file

source ~/.zshrc or source ~/.bashrc

Using

1. gitrewrite
   • you will be asked for a base branch (usually your development branch develop or master)
     • If the give branch does not exists, it will fail and exit
   • If the branch exists you will be asked for the new commit message
     • The script will reset the branch, add all the files and commit with the supplied message
     • All commands that are ran are printed on the console