Sync labels between repositories

labels.sh

#!/usr/bin/env bash

# run as: ./labels.sh path/to/source/repository path/to/target/repository
# first check if this is sufficient: gh label clone owner/source-repo
# make sure you won't miss the info of issues and PRs attached to the labels the script will delete

PS4='\033[31m$0:$LINENO: \033[0m'
set -eEo pipefail

test $# -eq 2
test -d "$1"
test -d "$2"

which bash
which comm
which gh
which jq

target="$(cd "$1" && gh label list --json name,description,color)"
current="$(cd "$2" && gh label list --json name,description,color)"
targetTags="$(echo "$target" | jq -r '.[].name' | sort)"
currentTags="$(echo "$current" | jq -r '.[].name' | sort)"
toCreateTags="$(comm -23 <(echo "$targetTags") <(echo "$currentTags"))"
toDeleteTags="$(comm -13 <(echo "$targetTags") <(echo "$currentTags"))"
toUpdateTags="$(comm -12 <(echo "$targetTags") <(echo "$currentTags"))"

if test "$toCreateTags"; then
  echo "Will be created:"
  echo "$toCreateTags"
  echo
fi

if test "$toUpdateTags"; then
  echo "Will be checked to update:"
  echo "$toUpdateTags"
  echo
fi

if test "$toDeleteTags"; then
  echo "Will be deleted:"
  echo "$toDeleteTags"
  echo
fi

read -rn 1 -p "Press any key..."

(
  cd "$2"

  # create new
  echo "$toCreateTags" | while read -r TAG; do
    if test -z "$TAG"; then continue; fi
    DESC="$(echo "$target" | jq -jr --arg TAG "$TAG" '.[] | select(.name == $TAG) | .description')"
    COLR="$(echo "$target" | jq -jr --arg TAG "$TAG" '.[] | select(.name == $TAG) | .color')"
    set -x
    gh label create "$TAG" --description "$DESC" --color "$COLR"
    set +x
  done

  # delete irrelevant
  echo "$toDeleteTags" | while read -r TAG; do
    if test -z "$TAG"; then continue; fi
    set -x
    gh label delete --yes "$TAG"
    set +x
  done

  # update existing
  echo "$toUpdateTags" | while read -r TAG; do
    if test -z "$TAG"; then continue; fi
    CURRNT_DESC="$(echo "$current" | jq -jr --arg TAG "$TAG" '.[] | select(.name == $TAG) | .description')"
    TARGET_DESC="$(echo "$target" | jq -jr --arg TAG "$TAG" '.[] | select(.name == $TAG) | .description')"
    if test -z "$CURRNT_DESC"; then CURRNT_DESC=" "; fi
    if test -z "$TARGET_DESC"; then TARGET_DESC=" "; fi # gh prevents deleting description
    if test "$TARGET_DESC" != "$CURRNT_DESC"; then
      set -x
      gh label edit "$TAG" --description "$TARGET_DESC"
      set +x
    fi

    CURRNT_COLR="$(echo "$current" | jq -jr --arg TAG "$TAG" '.[] | select(.name == $TAG) | .color')"
    TARGET_COLR="$(echo "$target" | jq -jr --arg TAG "$TAG" '.[] | select(.name == $TAG) | .color')"
    if test "$TARGET_COLR" != "$CURRNT_COLR"; then
      set -x
      gh label edit "$TAG" --color "$TARGET_COLR"
      set +x
    fi
  done
)