ci/request-reviews/get-code-owners.sh: First-class code owner team review requests

#!/usr/bin/env bash

# Get the code owners of the files changed by a PR, returning one username per line

# Get the code owners of the files changed by a PR, returning one GitHub user/team handle per line

set -euo pipefail

# remove code owners to avoid pinging them

git -C "$gitRepo" show "$baseRef":"$ownersFile" > "$tmp"/codeowners

# Associative array with the user as the key for easy de-duplication

# Associative array with the user/team as the key for easy de-duplication

# Make sure to always lowercase keys to avoid duplicates with different casings

declare -A users=()

declare -A finalOwners=()

for file in "${touchedFiles[@]}"; do

    result=$(codeowners --file "$tmp"/codeowners "$file")

        # The first regex match is everything after the @

        entry=${BASH_REMATCH[1]}

        if [[ "$entry" =~ (.*)/(.*) ]]; then

            # Teams look like $org/$team

            org=${BASH_REMATCH[1]}

            team=${BASH_REMATCH[2]}

            # Instead of requesting a review from the team itself,

            # we request reviews from the individual users.

            # This is because once somebody from a team reviewed the PR,

            # the API doesn't expose that the team was already requested for a review,

            # so we wouldn't be able to avoid rerequesting reviews

            # without saving some some extra state somewhere

            # We could also consider implementing a more advanced heuristic

            # in the future that e.g. only pings one team member,

            # but escalates to somebody else if that member doesn't respond in time.

            gh api \

                --cache=1h \

                -H "Accept: application/vnd.github+json" \

                -H "X-GitHub-Api-Version: 2022-11-28" \

                "/orgs/$org/teams/$team/members" \

                --jq '.[].login' > "$tmp/team-members"

            readarray -t members < "$tmp/team-members"

            log "Team $entry has these members: ${members[*]}"

            for user in "${members[@]}"; do

                users[${user,,}]=

            done

        else

            # Everything else is a user

            users[${entry,,}]=

        fi

        finalOwners[${entry,,}]=

    done

done

printf "%s\n" "${!users[@]}"

printf "%s\n" "${!finalOwners[@]}"