pathprepend() {
  for ((i=$#; i>0; i--));
  do
    ARG="$@[$i]"
    if [ -d "$ARG" ] && [[ ":$PATH:" != *":$ARG:"* ]]; then
        PATH="$ARG${PATH:+":$PATH"}"
    fi
  done
}

# paths are prepend in order, so you can manage with version will run
# by the order of this array
CUSTOM_PATHS=(
  "~/polkadot/target/release"
  "~/polkadot/target/testnet"
  "~/cumulus/target/release"
)

pathprepend $CUSTOM_PATHS
export PATH=$PATH