git-mark-reviewed

#!/usr/bin/env bash

set -o pipefail
. "$(git --exec-path)/git-sh-setup"
#
# Also see "$(git --exec-path)/git-filter-branch" for, e.g., a list of
# functions available in the commit filter.

# set_reflog_action

contains() {
    local match="$1"; shift
    local el
    for el; do [[ $el == $match ]] && return 0; done
    return 1
}

default_author() {
    local a_tree=$(git cat-file -p @ | sed -n -e 's/tree //p')
    local a_commit=$(git commit-tree -m '' $a_tree </dev/null)
    git cat-file -p $a_commit \
        | sed -n -e 's/ [0-9]* +[0-9]*$//' -e 's/author //p'
}

branches_with() {
    [[ -n $1 || -z $2 ]] || die "INTERNAL ERROR: branches: bad args"
    git branch --list --format='%(refname)' --contains "$1"
}

############################################################
# Main

reviewer="$(default_author)"
branch=
dry_run=false
force=false
while true; do case "$1" in
    -b|--branch)        shift; branch="$1"; shift;;
    -f|--force)         shift; force=true;;
    -n|--dry-run)       shift; dry_run=true;;
    -r|--reviewer)      shift; reviewer="$1"; shift;;
    *)                  break;;
esac; done

# Canonicalize ref name (HEAD if not specified)
ref="$(git rev-parse --symbolic-full-name --short ${branch:-@} 2>/dev/null)"
[[ -z $ref ]] && die "Unknown ref: $branch"

# Create list of individual commits (in abbreviated hash format)
commits=()
for i in "$@"; do
    if [[ $i =~ \.\. ]]; then
        commits+=($(git log --format=%h "$i"))
    else
        commits+=($(git log --format=%h -1 "$i"))
    fi
done
#for i in "${commits[@]}"; do echo commit: $i; done

# Ensure all commits are on the given branch
for i in "${commits[@]}"; do
    # XXX For some reason, `git-branch` says that `refs/heads/foo` doesn't
    # contain a commit when `foo` contains it. We hack by removing the
    # `refs/heads` prefix, but there must be a better/more reliable way....
    [[ -n $(git branch --contains "$i" "${ref#refs/heads/}") ]] \
        || die "Branch $ref doesn't contain commit $i"
done

# Here it would be nice to figure out the earliest commit so we didn't
# have to rewrite the entire branch back to the beginning. It would also
# reduce the amount of output generated by progress mesages, which can
# be considerable. (There's no way to disable the progress messages, and
# if they're longer than a terminal line there are many, many lines of
# output due to `\n` going back to beginning of line instead of message.)

echo "Marking these commits on $ref as"
echo "  Reviewed-by: $reviewer"
for i in "${commits[@]}"; do
    git log -n 1 --format='%h %ae %s' "$i" | sed -e 's/@[^ ]*/@/'
done
$dry_run && exit 1
$force || {
    read -p 'OK? [y/N]' ok
    [[ $ok =~ ^[Yy] ]] || die "Aborted"
}
echo

trailer_config="-c trailer.where=after \
    -c trailer.ifmissing=add -c trailer.ifexists=addIfDifferent \
" # User may override trailer.separators (default `:`) if he likes.

# To avoid halting due to the existence of a `refs/original` entry
# from a previous `git filter-branch` we use `--force` to wipe it out
# (which wipes out its reflog, too). We compensate by ensuring a
# reflog is created for the branch we're filtering.
#
echo XXX rewriting "'$ref'"
commits="${commits[@]}"     # convert to space separated due to quoting below
git -c core.logAllRefUpdates=always  filter-branch --force \
    --msg-filter "
        for id in $commits; do
            [[ \$GIT_COMMIT =~ ^\$id ]] && {
                git $trailer_config interpret-trailers \
                    --trailer 'Reviewed-by: $reviewer'
                exit
            }
        done
        cat
    " "$ref"