},
		},
		{
			name: "messageExpression inclusion",
			input: schema.Structural{
				Generic: schema.Generic{
					Type: "string",
				},
				ValidationExtensions: schema.ValidationExtensions{
					XValidations: apiextensions.ValidationRules{
						{
							Rule:              "self.startsWith('s')",
							MessageExpression: `"scoped field should start with 's'"`,
						},
					},

  optional string reason = 3;

  // messageExpression declares a CEL expression that evaluates to the validation failure message that is returned when this rule fails.
  // Since messageExpression is used as a failure message, it must evaluate to a string.
  // If both message and messageExpression are present on a validation, then messageExpression will be used if validation fails.

	// messageExpression declares a CEL expression that evaluates to the validation failure message that is returned when this rule fails.
	// Since messageExpression is used as a failure message, it must evaluate to a string.
	// If both message and messageExpression are present on a validation, then messageExpression will be used if validation fails.