git-tfs-merge-into

#!/bin/sh

ME=$(basename "$0")

usage () {
        cat <<EOF

Usage: $ME <destination_branch>

  This command merges the currently checked out git branch, whose parent is a
  branch associated with a TFS remote, to <destination_branch> using the
  Git-TFS rcheckin command.

  This script will peform the following actions:

    1. Ensures <destination_branch> is a branch associated with a Git-TFS TFS
       remote.
    2. Ensures your local copy of <destination_branch> is up-to-date with TFS
         - Any changes brought down will be pushed to <destination_branch>'s
           remote tracking branch.
    3. If <destination_branch> was updated, the current branch will be rebased
       on top of <destination_branch>
    4. Your branch's commits will be replayed to the TFS remote for
       <destination_branch> as TFS changesets
    5. Your local copy of <destination_branch> will be updated from TFS again
    6. The new changesets will be pushed to the remote tracking branch for
       <destination_branch>
    7. The local branch you merged will be deleted
    8. The remote tracking branch associated with your local branch will be
       deleted.

EOF
        exit 1
}

die () {
        test $# -gt 0 || echo "$(tput setaf 1)Failed to merge '$SRC_BRANCH' into '$DEST_BRANCH'.$(tput sgr0)" >&2 && echo "$*" >&2
        exit 1
}

write_info () {
        echo "
$(tput setaf 14)$*$(tput sgr0)"
}

write_warning () {
        echo "
$(tput setaf 11)$*$(tput sgr0)" >&2
}

not_rebasing() {
        local retVal;
        test ! -d "${GIT_DIR:-.git}"/rebase-apply
        retVal=$?
        exit $retVal
}

get_upstream() {
        test $# = 2 || exit 1

        case $1 in
                --remote|-r)
                        echo "$2" | sed -e 's|\([^/]*\)/\(.*\)|\1|' ;;
                --branch|-b)
                        echo "$2" | sed -e 's|\([^/]*\)/\(.*\)|\2|' ;;
        esac
}

test $# = 1 || usage

FOUND_GIT_TFS=
SRC_BRANCH=
SRC_BRANCH_UPSTREAM=
DEST_BRANCH=
DEST_BRANCH_UPSTREAM=
DEST_BRANCH_TFS=
REBASING_MSG="
$(tput setaf 1)ERROR: Rebase in progress. Please finish the rebase operation in progress or
abort the rebase and try again.$(tput sgr0)
"

case $1 in
        -h|-help)
                usage
                ;;
        *)
                FOUND_GIT_TFS="$(which git-tfs)" && test -n "$FOUND_GIT_TFS" || die "
$(tput setaf 1)ERROR: git-tfs could not be found. Please ensure you installed git-tfs and that
git-tfs.exe is in your PATH.$(tput sgr0)
"
                DEST_BRANCH_TFS=$(git config --local --get tfs-remote."$(git config --local --get git-tfs-branch."$1".remote)".repository) || die "
$(tput setaf 1)ERROR: '$1' is not associated with a Git-TFS remote.$(tput sgr0)
Did you forget to issue a $(tput setaf 13)'git tfs bootstrap'$(tput sgr0) command on '$1'?
See '$ME -help' for more information.
"
                SRC_BRANCH="$(git rev-parse --abbrev-ref HEAD)"
                SRC_BRANCH_UPSTREAM="$(git rev-parse --abbrev-ref "$SRC_BRANCH"@{u})"
                DEST_BRANCH="$1"
                DEST_BRANCH_UPSTREAM="$(git rev-parse --abbrev-ref "$DEST_BRANCH"@{u})"
                echo
                ;;
esac

test -n "$(get_upstream -b "$SRC_BRANCH_UPSTREAM")" || die "$(tput setaf 1)ERROR: '$SRC_BRANCH' is not tracking a remote branch.$(tput sgr0)
Please issue the following command to setup a remote tracking branch for
'$SRC_BRANCH':

    git branch --set-upstream-to=<remote_name>/<remote_branch_name>

For example:

    git branch --set-upstream-to=origin/feature/my-topic-branch

"

test ! "$SRC_BRANCH" = "$DEST_BRANCH" || die "$(tput setaf 1)ERROR: Cannot merge '$DEST_BRANCH' to '$DEST_BRANCH_TFS'$(tput sgr0)"

cat <<EOF
Branch Information
===============================================================================
Local source branch name:           $SRC_BRANCH
Upstream source branch remote:      $(get_upstream -r "$SRC_BRANCH_UPSTREAM")
Upstream source branch name:        $(get_upstream -b "$SRC_BRANCH_UPSTREAM")

Local destination branch name:      $DEST_BRANCH
Upstream destination branch remote: $(get_upstream -r "$DEST_BRANCH_UPSTREAM")
Upstream destination branch name:   $(get_upstream -b "$DEST_BRANCH_UPSTREAM")
Destination branch TFS remote:      $DEST_BRANCH_TFS
EOF

test "$SRC_BRANCH" = "$(get_upstream -b "$SRC_BRANCH_UPSTREAM")" || (
        CONTINUE=n
        read -n 1 -p "
$(tput setaf 11)WARNING:$(tput sgr0) Your local branch name:

        $(tput setaf 10)'$SRC_BRANCH'$(tput sgr0)

    is different than the remote tracking branch name:

        $(tput setaf 9)'$SRC_BRANCH_UPSTREAM'$(tput sgr0)

Please ensure the branch information above is correct before continuing.

$(tput setaf 15)Do you want to continue merging?$(tput sgr0) [y|$(tput setaf 11)N$(tput sgr0)] ? " CONTINUE

        case "$CONTINUE" in
                y|Y)    echo
                        exit 0
                        ;;
                *)
                        exit 1
                        ;;
        esac
) || die "

$(tput setaf 1)Merging canceled.$(tput sgr0)
"

(case "$DEST_BRANCH" in
        "develop"|"master")
                CONTINUE=n
                read -n 1 -p "
$(tput setaf 11)WARNING:$(tput sgr0) You are merging into $(tput setaf 13)'$DEST_BRANCH'$(tput sgr0), are you sure (y|$(tput setaf 15)N$(tput sgr0))? " CONTINUE
                case "$CONTINUE" in
                        y|Y)    echo
                                exit 0
                                ;;
                        *)
                                exit 1
                                ;;
                esac
        ;;
esac) || die "

$(tput setaf 1)Merging canceled.$(tput sgr0)
"

# Update the local copy of the destination branch from the git server
(write_info "Updating '$DEST_BRANCH' with any upstream commits" &&
        (
                git checkout "$DEST_BRANCH" && \
                git fetch && \
                git rebase "$DEST_BRANCH_UPSTREAM" && \
                not_rebasing
        ) || die "$REBASING_MSG"
) || die

# Update the local copy of the destination branch with any changesets in TFS but not in git
(write_info "Updating '$DEST_BRANCH' with any new changesets from '$DEST_BRANCH_TFS'" && \
        (
                git tfs pull -x -r && \
                not_rebasing
        ) || die "$REBASING_MSG"
) || die

# At this point we can minimally push the new TFS changes to origin
(write_info "Updating '$DEST_BRANCH_UPSTREAM' with any new commits on '$DEST_BRANCH'" && \
        git push $(get_upstream -r "$DEST_BRANCH_UPSTREAM") refs/notes/*:refs/notes/* "$DEST_BRANCH":"$(get_upstream -b "$DEST_BRANCH_UPSTREAM")"
) || die

# Rebase the local topic branch on top of the local copy of the destination branch
(write_info "Rebasing '$SRC_BRANCH' on '$DEST_BRANCH' and updating '$SRC_BRANCH_UPSTREAM'" &&
        (
                git checkout "$SRC_BRANCH" && \
                git rebase "$DEST_BRANCH" && \
                not_rebasing && \
                git push $(get_upstream -r "$SRC_BRANCH_UPSTREAM") +"$SRC_BRANCH":"$(get_upstream -b "$SRC_BRANCH_UPSTREAM")"
        ) || die "$REBASING_MSG"
) || die

# Replay each commit and checkin each commit to TFS
(write_info "Checking in '$SRC_BRANCH' to '$DEST_BRANCH_TFS'" && git tfs rcheckin) || die

# Rebase the local copy of the destination branch on top of the remote TFS branch
write_info "Pulling from '$DEST_BRANCH_TFS' into '$DEST_BRANCH'" &&
(
        git checkout "$DEST_BRANCH" && \
        git tfs pull -x -r && \
        not_rebasing
) || \
die "$(write_warning "WARNING: Encountered an error while pulling from '$DEST_BRANCH_TFS'.
The branch '$SRC_BRANCH' was successfully merged into '$DEST_BRANCH'.
However, no other clean up operations will be performed.
Please resolve the issue and run the following commands:

    $ git tfs pull -x -r
    $ git push $(get_upstream -r "$DEST_BRANCH_UPSTREAM") refs/notes/*:refs/notes/* "$DEST_BRANCH":"$(get_upstream -b "$DEST_BRANCH_UPSTREAM")"
    $ git branch -f "$SRC_BRANCH" "$DEST_BRANCH"
    $ git push $(get_upstream -r "$SRC_BRANCH_UPSTREAM") +"$SRC_BRANCH":"$(get_upstream -b "$SRC_BRANCH_UPSTREAM")"
    $ git push $(get_upstream -r "$SRC_BRANCH_UPSTREAM") :"$(get_upstream -b "$SRC_BRANCH_UPSTREAM")"
    $ git branch -d "$SRC_BRANCH"
")"

# Push the updated local copy of the destination branch to the Git server
(write_info "Updating '$SRC_BRANCH_UPSTREAM' with '$SRC_BRANCH' and
'$DEST_BRANCH_UPSTREAM' with '$DEST_BRANCH'" && \
        git branch -f "$SRC_BRANCH" "$DEST_BRANCH" && \
        git push $(get_upstream -r "$SRC_BRANCH_UPSTREAM") +"$SRC_BRANCH":"$(get_upstream -b "$SRC_BRANCH_UPSTREAM")" && \
        git push $(get_upstream -r "$DEST_BRANCH_UPSTREAM") refs/notes/*:refs/notes/* "$DEST_BRANCH":"$(get_upstream -b "$DEST_BRANCH_UPSTREAM")" 
) || \
die "$(write_warning "WARNING: Encountered an error while updating branches.

The branch '$SRC_BRANCH' was successfully merged into '$DEST_BRANCH'.
However, no other clean up operations will be performed.
Please ensure everything is OK and then run the following commands:

    $ git push $(get_upstream -r "$DEST_BRANCH_UPSTREAM") refs/notes/*:refs/notes/* "$DEST_BRANCH":"$(get_upstream -b "$DEST_BRANCH_UPSTREAM")"
    $ git branch -f "$SRC_BRANCH" "$DEST_BRANCH"
    $ git push $(get_upstream -r "$SRC_BRANCH_UPSTREAM") +"$SRC_BRANCH":"$(get_upstream -b "$SRC_BRANCH_UPSTREAM")"
    $ git push $(get_upstream -r "$SRC_BRANCH_UPSTREAM") :"$(get_upstream -b "$SRC_BRANCH_UPSTREAM")"
    $ git branch -d "$SRC_BRANCH"
")"

(write_info "Deleting '$SRC_BRANCH'" && \
        git checkout "$DEST_BRANCH" && \
        git branch -d "$SRC_BRANCH"
) || \
write_warning "WARNING: Unable to delete '$SRC_BRANCH'."

(write_info "Deleting '$SRC_BRANCH_UPSTREAM'" && \
        git push $(get_upstream -r "$SRC_BRANCH_UPSTREAM") :"$SRC_BRANCH"
) || \
write_warning "WARNING: Unable to delete the remote branch '$SRC_BRANCH_UPSTREAM'.
Please ensure everything is OK and then run the following command:

    git push $(get_upstream -r "$SRC_BRANCH_UPSTREAM") :\"$SRC_BRANCH\"
"

echo "
$(tput setaf 10)SUCCESS: Checked in '$SRC_BRANCH' to '$DEST_BRANCH_TFS',
updated '$DEST_BRANCH',
and '$DEST_BRANCH_UPSTREAM'.$(tput sgr0)
"