feat: add monetary data validator

app/controllers/api/v1/monetary_data_controller.rb

@@ -1,11 +1,24 @@
 module Api
   module V1
     class MonetaryDataController < ApplicationController
+      before_action :validate_query_params, only: :show
+
       def show
         monetary_data = MonetaryData.new
 
         render json: MonetaryDataSerializer.new(monetary_data, params: { indicator: params[:id] })
       end
+
+      def validate_query_params
+        validator = Validations::DistributionData.new(params)
+
+        if validator.invalid?
+          errors = validator.error_object[:errors]
+          status = validator.error_object[:status]
+
+          render json: errors, status: status
+        end
+      end
     end
   end
 end

app/controllers/validations/monetary_data.rb

@@ -0,0 +1,33 @@
+module Validations
+  class MonetaryData
+    include ActiveModel::Validations
+
+    validate :query_key_format_must_be_correct
+
+    def initialize(params = {})
+      @query_key = params[:id]
+    end
+
+    def error_object
+      api_errors = []
+
+      if invalid?
+        api_errors << Api::V1::Exceptions::IndicatorNameInvalidError.new if :query_key.in?(errors.keys)
+        {
+          status: api_errors.first.status,
+          errors: RequestErrorSerializer.new(api_errors, message: api_errors.first.title)
+        }
+      end
+    end
+
+    private
+
+    attr_accessor :query_key
+
+    def query_key_format_must_be_correct
+      if query_key.blank? || !(query_key.split("-") - ::MonetaryData::VALID_INDICATORS).empty?
+        errors.add(:query_key, "indicator name is invalid")
+      end
+    end
+  end
+end