CHECK_FILENAME=.gopath

setGoPath() {
  if [ -f "$PWD/$CHECK_FILENAME" ]; then
    if ! [[ "$GOPATH" =~ (^|:)"$PWD"(:|$) ]]; then
      echo "Adding $PWD to GOPATH"
      export GOPATH=$GOPATH:$PWD
      echo $GOPATH
    fi
  fi
}

if [ "$PROMPT_COMMAND" != "*setGoPath*" ]; then
  export PREV_PROMPT_COMMAND=$PROMPT_COMMAND
  export PROMPT_COMMAND="$PROMPT_COMMAND; setGoPath"
fi