CustomFunction Return Error

/**
 * CustomFunction Return Error
 * @customfunction
 * @param {number} errorCase
 * @returns error
 */
function customErrorReturn(errorCase) {
  switch (errorCase) {
    case 1: {
      var error = new CustomFunctions.Error(
        CustomFunctions.ErrorCode.notAvailable, // #N/A
        "An error *case 1* was detected in customErrorReturn"
      );
      return error;
    }
    case 2: {
      var error = new CustomFunctions.Error(
        CustomFunctions.ErrorCode.invalidValue, // #VALUE!
        "An error *case 2* was detected in customErrorReturn"
      );
      return error;
    }
    case 3: {
      var error = new CustomFunctions.Error(
        CustomFunctions.ErrorCode.divisionByZero, // #DIV/0!
        "This message should not appear in UI"
      );
      return error;
    }
    case 4: {
      var error = new CustomFunctions.Error(
        CustomFunctions.ErrorCode.invalidNumber, // #NUM!
        "This message should not appear in UI"
      );
      return error;
    }
    case 5: {
      var error = new CustomFunctions.Error(
        CustomFunctions.ErrorCode.nullReference, // #NULL!
        "This message should not appear in UI"
      );
      return error;
    }
    case 6: {
      var error = new CustomFunctions.Error(
        CustomFunctions.ErrorCode.notAvailable // #N/A!
      );
      return error;
    }
    case 7: {
      var error = new CustomFunctions.Error(); // #VALUE!
      return error;
    }
    case 8: {
      var error = new CustomFunctions.Error(
        undefined, // #VALUE!
        "An error *case 8* was detected in customErrorReturn"
      );
      return error;
    }
    case 9: {
      var error = new CustomFunctions.Error(
        "Customized", // #VALUE!
        "An error *case 9* was detected in customErrorReturn"
      );
      return error;
    }
    case 10: {
      var error = new CustomFunctions.Error(new Error()); // #VALUE!
      return error;
    }
    case 11: {
      return new Error("This message should not appear in UI"); // #VALUE!
    }
    default: {
      var error = new CustomFunctions.Error(
        CustomFunctions.ErrorCode.notAvailable,
        "An unknown error case was detected in customErrorReturn"
      );
      return error;
    }
  }
}

/**
 * CustomFunction Return Error Array
 * @customfunction
 * @param {number} errorCase
 * @returns {any[][]}
 */
function customErrorReturnArray(errorCase) {
  switch (errorCase) {
    case 1: {
      var error = new CustomFunctions.Error(
        CustomFunctions.ErrorCode.notAvailable, // #N/A
        "An error *case 1* was detected in customErrorReturnArray "
      );
      return [["Hello"], [error]];
    }
    case 2: {
      var error1 = new CustomFunctions.Error(
        CustomFunctions.ErrorCode.notAvailable, // #N/A
        "An error *case 1* was detected in customErrorReturnArray "
      );
      var error2 = new CustomFunctions.Error(
        CustomFunctions.ErrorCode.invalidValue, // #VALUE!
        "An error *case 2* was detected in customErrorReturnArray "
      );
      return [[error1], [error2]];
    }
  }
}