git-vbranch

#!/bin/bash
# Copyright (c) 2010, Nicolas Pouillard
# All rights reserved.
#
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# modification, are permitted provided that the following conditions are
# met:
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#       with the distribution.
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# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

info() {
  echo "$@" > /dev/stderr
}

err() {
  echo "$@" > /dev/stderr
}

usage() {
  cat > /dev/stderr <<EOS
Usage: git vbranch (show|merge|create|reset) [<virtual-branch>]

  # Purpose

  'git vbranch' aims at dealing with your topic branches easily.

  As a contributor to a project you may want to isolate each of your
  contributions as what is called a topic branch. A topic branch is a short
  living branch that fix a particular bug, add a specific feature, etc.  In
  this situation you branch off master for each of your topics.  You propose
  those topics to upstream, but in the mean time you may have to integrate
  upstream changes, improve your topics, and enjoy having all your topics
  merged in a big local branch of yours.  This script is about this last
  branch that I personally name the "my" branch, and that we will call a
  virtual branch.  This script helps to manage which topic branches are
  behind a given virtual branch, and create/merge/reset this
  virtual branch.

  # Setup
  git config virtual.<virtual-branch>.base <base-branch>
  git config virtual.<virtual-branch>.topics <topics>
  git config virtual.default <virtual-branch>

  # Hint: Using a virtual.default configuration allows to omit
  # the <virtual-branch> argument to vbranch commands.

  # Setup Example
  git config virtual.my.base master
  git config virtual.my.topics topic1,topic2,bugfix3,feature4
  git config virtual.default my

  # Show details of a virtual branch (however 'git wtf' is much
  # better at this (http://git-wt-commit.rubyforge.org/).
  git vbranch show [<virtual-branch>]

  # Merge in all the topic branches associated to this virtual branch
  git vbranch merge [<virtual-branch>]

  # Create the virtual branch and 'merge'
  git vbranch create [<virtual-branch>]

  # Hard reset the virtual branch to the base branch and 'merge'
  git vbranch reset [<virtual-branch>]
EOS
  exit 1
}

cmd="$1"
shift
if [ -z "$cmd" ]; then
  err "no command"
  usage
fi

case "$1" in
-*|"")
  vbranch=$(git config virtual.default || :);;
*)
  vbranch="$1"
  shift;;
esac
if [ -z "$vbranch" ]; then
  err "No virtual branch name argument nor configuration value for virtual.default"
  usage
fi

base=$(git config virtual."$vbranch".base)
if [ -z "$base" ]; then
  err "Virtual branch $vbranch not configured."
  err "Configuration option virtual.$vbranch.base is empty"
  exit 1
fi

topics=$(git config virtual."$vbranch".topics)
if [ -z "$topics" ]; then
  err "Virtual branch $vbranch not configured."
  err "Configuration option virtual.$vbranch.topics is empty"
  exit 1
fi

basehash=$(git show-ref -s heads/$base)
if [ -z "$basehash" ]; then
  err "The base branch ('$base') of '$vbranch' should exists."
  exit 1
fi

merge() {
  info "Merging all the topics to branch '$vbranch'..."
  echo -n "$topics" | xargs -d, git merge
}

create() {
  vbranchhash=$(git show-ref -s heads/$vbranch)
  if [ -z "$vbranchhash" ]; then
    info "Making and checking out the virtual branch..."
    git checkout -b "$vbranch" "$base"
    merge "$@"
  else
    err "The branch $vbranch already exists, use 'vbranch reset' to overwrite it."
    exit 1
  fi
}

no_more_args() {
  if [ $# != 0 ]; then
    err "No more arguments expected"
    usage
  fi
}

case "$cmd" in
create|c|cr|cre|crea|creat)
  create "$@";;
merge|m|me|mer|merg|merge)
  merge "$@";;
reset|rese|res|re|r)
  info "Reseting the virtual branch..."
  git checkout "$vbranch"
  git reset --hard "$base"
  merge "$@";;
show)
  no_more_args "$@"
  echo "=== Virtual branch '$vbranch' ==="
  echo "Base branch:"
  echo "* $base"
  echo "Topic branches:"
  echo -n "$topics" | xargs -d, -n 1 echo '*' ;;
*)
  usage;;
esac

This solves a long standing problem for me. Thanks!

Thanks for sharing this! Are there any similar tools in this space? I was surprised that I didn't find lots of different Git branching tools for maintaining forks and being able to push those changes back upstream.