git-review

#!/bin/bash

SVN="svn/trunk"
MASTER="master"

die() { echo "$@" >&2; exit 1; }

ensure_clean()
{
  if ! git diff --no-ext-diff --ignore-submodules --quiet --exit-code; then
    die ">> FATAL: Working tree contains unstaged changes. Aborting"
  elif ! git diff-index --cached --quiet --ignore-submodules HEAD --; then
    die ">> FATA: Index contains uncommitted changes. Aborting"        
  fi
}

ensure_review_branch()
{
  parse_review_branch
  [[ -z "$REVIEW_BRANCH" ]] && die ">> FATAL: Current branch must be in the form 'review/xx'"
}

parse_review_branch()
{
  REVIEW_BRANCH=$(git symbolic-ref HEAD | grep -E 'refs/heads/review/[[:digit:]]' | cut -d '/' -f 3-)
  REVIEW_ID=$(echo "$REVIEW_BRANCH" | cut -d '/' -f 2)
}

label_branch()
{

  local review_id="$1"
  (
    cd "$(git rev-parse --show-toplevel)";
    git filter-branch -f --msg-filter "sed -e \"/Review-ID:/d\" | sed -e :a -e \"/^\\n*$/N;/\\n$/ba\" && echo \"\\nReview-ID: $review_id\"" $SVN..HEAD
  )
  git for-each-ref --format="%(refname)" refs/original/ | xargs -n 1 git update-ref -d
}

branch_name_for_hash()
{
  local hash="$@"
  echo $(git for-each-ref --format="%(objectname)%09%(refname:short)" refs/heads/ | grep "$hash" | cut -f 2 | head -n 1)
}

find_revision_range()
{
  # If they passed --revision-range, we don't add our own
  if [[ "$@" == *--revision-range=* ]]; then
    REVISION_RANGE=""
    return
  fi

  local head=$(git rev-parse HEAD)

  local latest_review=$(git for-each-ref --format="%(objectname)" refs/heads/review/* | { \
    while read commit; do
      # Is it a direct ancestor, but not the current commit?
      if [[ "$commit" != "$head" && "$(git merge-base HEAD "$commit")" = "$commit" ]]; then
        # Is it newer than the previously-stored revision branch?
        if [[ -z "$latest_review" || "$(git merge-base "$commit" "$latest_review")" = "$latest_review" ]]; then
          latest_review="$commit"
        fi
      fi
    done
    echo $latest_review
  })

  if [[ -z "$latest_review" ]]; then
    REVISION_RANGE=""
  else  
    echo ">> Found revision range: $(branch_name_for_hash "$latest_review")"
    REVISION_RANGE="--revision-range=$latest_review"
  fi
}

cmd_label()
{
  ensure_clean
  # They can either pass the review ID as the first arg, or be on a review branch
  local review_id="$1"
  [[ -z "$review_id" ]] && parse_review_branch && review_id="$REVIEW_ID"
  [[ -z "$review_id" ]] && die ">> FATAL: Either be on a review branch, or pass in the review ID as an argument"
  label_branch $review_id
}

cmd_submit()
{
  ensure_clean
  parse_review_branch
  find_revision_range "$@"

  # If it's not an update, and they're on a review branch, it's probably a mistake
  [[ -n "$REVIEW_ID" ]] && die ">> FATAL: It looks like you're on a review branch. This is probably a mistake?" 
  
  local regex="Review request #([[:digit:]]+) posted"
  
  local full_output=$(post-review "$REVISION_RANGE" "$@")
  echo "$full_output"

  local filtered_output=$(echo "$full_output" | grep -E "$regex")

  [[ "$filtered_output" =~ $regex ]] || die ">> FATAL: Could not find review ID in output"
  local review_id=${BASH_REMATCH[1]}
  local review_branch="review/$review_id"

  git show-ref --verify --quiet refs/heads/$review_branch
  [[ $? -eq 0 ]] && die ">> Review branch $review_branch already exists, so not touching it"

  git checkout -b $review_branch
}

cmd_update()
{
  ensure_clean
  ensure_review_branch
  find_revision_range "$@"

  post-review -r "$REVIEW_ID" --diff-only --no-guess-fields --no-guess-summary --no-guess-description "$REVISION_RANGE" "$@"
}

cmd_commit()
{
  ensure_clean
  ensure_review_branch

  # Make sure we're up to date
  git svn fetch
  [[ "$(git merge-base $SVN HEAD)" != "$(git rev-parse $SVN)" ]] && die ">> FATAL: Rebase onto $SVN"

  git checkout $MASTER
  git merge --ff-only $REVIEW_BRANCH || die ">> FATAL: Failed to fast-forward master to $REVIEW_BRANCH"
  git branch -d $REVIEW_BRANCH
  
  label_branch $REVIEW_ID
  
  git svn dcommit

  rbt close --close-type=submitted $REVIEW_ID
}

cmd_apply()
{
  ensure_clean

  local review_id="$1"
  [[ -z "$review_id" ]] && parse_review_branch && review_id=$REVIEW_ID
  [[ -z "$review_id" ]] && die ">> FATAL: Either be on a review branch, or pass in the review ID as an argument"
  local review_branch="review/$review_id"

  if [[ -n "$REVIEW_BRANCH" ]]; then
    echo ">> Branch $REVIEW_BRANCH already exists. Resetting to $SVN"
    [[ "$(git symbolic-ref HEAD)" != "refs/heads/$REVIEW_BRANCH" ]] && git checkout $REVIEW_BRANCH
    git reset --hard $SVN
  else
    local review_branch="review/$review_id"
    echo ">> Creating $review_branch, based on $SVN"
    git checkout -b $review_branch $SVN
  fi

  rbt patch --px=0 $review_id
}

usage()
{
  echo "Usage: $0 [submit|label|update|commit|apply] [review-id] [args]"
  echo
  echo "The commands label,update,apply will grab the review ID from the current branch"
  echo "name if avaible, or from the first argument (e.g. 'git review label 23')."
  echo
  echo "The commit command requires that you're on a review/xx branch, and submit doesn't"
  echo "care what branch you're on."
  echo
  echo "The submit and update commands will automatically determine the --revision-range"
  echo "argument (the latest review/xx branch that's an ancestor of HEAD) if this argument"
  echo "isn't given"
  echo
  echo "Subcommands:"
  echo "    submit: Runs 'post-review $@' on the current branch, and retrieves the ID,"
  echo "            then creates a branch review/xx at the current point."
  echo "    label:  For each commit between HEAD and $SVN, adds a Review-ID: xx line."
  echo "    update: Updates the review with a new patch, derived from the current HEAD."
  echo "    commit: Requires you to be on a review/xx branch. Merges the branch into master,"
  echo "            and dcommits, then closes the related review."
  echo "    apply:  If you're on a review/xx branch, resets it to $SVN and applies the latest"
  echo "            patch from ReviewBoard. If you're not, creates such a branch based on $SVN"
  echo "            and applies the patch. Useful to checking someone else's patch."
}

SUBCOMMAND="$1"
shift

case "$SUBCOMMAND" in
  submit)
    cmd_submit "$@"
    ;;
 
  label)
    cmd_label "$@"
    ;;

  update)
    cmd_update "$@"
    ;;

  commit)
    cmd_commit "$@"
    ;;

  apply)
    cmd_apply "$@"
    ;;

  *)
    usage
    exit 1
esac