Refactor beneficiary field mapping

app/models/aggregate_data_query.rb

@@ -28,7 +28,7 @@ def apply(scope)
   private
 
   def query_scope(scope)
-    joins_with = group_by_fields.pluck(:relation) + filter_fields.keys.pluck(:relation)
+    joins_with = group_by_fields.map(&:relation) + filter_fields.map { |f, _| f.relation }
     joins_with = joins_with.compact_blank.uniq
     scope = scope.joins(*joins_with) if joins_with.any?
     scope

app/models/beneficiary_field.rb

@@ -0,0 +1,33 @@
+class BeneficiaryField
+  def initialize(name:, column:, relation: nil)
+    @name = name
+    @column = column
+    @relation = relation
+  end
+
+
+  attr_reader :name, :column, :relation
+
+  def self.all
+    @all ||= [
+      self.new(name: "status", column: "status"),
+      self.new(name: "gender", column: "gender"),
+      self.new(name: "date_of_birth", column: "date_of_birth"),
+      self.new(name: "language_code", column: "language_code"),
+      self.new(name: "iso_country_code", column: "iso_country_code"),
+      self.new(name: "address.iso_region_code", column: "beneficiary_addresses.iso_region_code", relation: :addresses),
+      self.new(name: "address.administrative_division_level_2_code", column: "beneficiary_addresses.administrative_division_level_2_code", relation: :addresses),
+      self.new(name: "address.administrative_division_level_2_name", column: "beneficiary_addresses.administrative_division_level_2_name", relation: :addresses),
+      self.new(name: "address.administrative_division_level_3_code", column: "beneficiary_addresses.administrative_division_level_3_code", relation: :addresses),
+      self.new(name: "address.administrative_division_level_3_name", column: "beneficiary_addresses.administrative_division_level_3_name", relation: :addresses),
+      self.new(name: "address.administrative_division_level_4_code", column: "beneficiary_addresses.administrative_division_level_4_code", relation: :addresses),
+      self.new(name: "address.administrative_division_level_4_name", column: "beneficiary_addresses.administrative_division_level_4_name", relation: :addresses)
+    ]
+  end
+
+  def self.find(name)
+    result = all.find { |f| f.name == name }
+    raise ArgumentError, "Unknown field #{name}" if result.nil?
+    result
+  end
+end

app/request_schemas/v1/beneficiary_stats_request_schema.rb

@@ -1,21 +1,5 @@
 module V1
   class BeneficiaryStatsRequestSchema < ApplicationRequestSchema
-    Field = Struct.new(:name, :column, :relation, keyword_init: true)
-    FIELDS = {
-      "status" => Field.new(name: "status", column: "status"),
-      "gender" => Field.new(name: "gender", column: "gender"),
-      "date_of_birth" => Field.new(name: "date_of_birth", column: "date_of_birth"),
-      "language_code" => Field.new(name: "language_code", column: "language_code"),
-      "iso_country_code" => Field.new(name: "iso_country_code", column: "iso_country_code"),
-      "address.iso_region_code" => Field.new(name: "address.iso_region_code", column: "beneficiary_addresses.iso_region_code", relation: :addresses),
-      "address.administrative_division_level_2_code" => Field.new(name: "address.administrative_division_level_2_code", column: "beneficiary_addresses.administrative_division_level_2_code", relation: :addresses),
-      "address.administrative_division_level_2_name" => Field.new(name: "address.administrative_division_level_2_name", column: "beneficiary_addresses.administrative_division_level_2_name", relation: :addresses),
-      "address.administrative_division_level_3_code" => Field.new(name: "address.administrative_division_level_3_code", column: "beneficiary_addresses.administrative_division_level_3_code", relation: :addresses),
-      "address.administrative_division_level_3_name" => Field.new(name: "address.administrative_division_level_3_name", column: "beneficiary_addresses.administrative_division_level_3_name", relation: :addresses),
-      "address.administrative_division_level_4_code" => Field.new(name: "address.administrative_division_level_4_code", column: "beneficiary_addresses.administrative_division_level_4_code", relation: :addresses),
-      "address.administrative_division_level_4_name" => Field.new(name: "address.administrative_division_level_4_name", column: "beneficiary_addresses.administrative_division_level_4_name", relation: :addresses)
-    }.freeze
-
     GROUPS = [
       "gender",
       "language_code",
@@ -68,11 +52,11 @@ def output
       result = super
 
       result[:filter_fields] = result.fetch(:filter, {}).each_with_object({}) do |(filter, value), filters|
-        filters[FIELDS.fetch(filter.to_s)] = value
+        filters[BeneficiaryField.find(filter.to_s)] = value
       end
 
       result[:group_by_fields] = result[:group_by].map do |group|
-        FIELDS.fetch(group)
+        BeneficiaryField.find(group)
       end
 
       result

spec/models/agreegate_data_query_spec.rb → spec/models/aggregate_data_query_spec.rb

@@ -1,13 +1,13 @@
 require "rails_helper"
 
-RSpec.describe "AgreegateDataQuery", type: :model do
+RSpec.describe AggregateDataQuery, type: :model do
   it "return results with a simple group by field" do
     create_list(:beneficiary, 2, gender: "M")
     create_list(:beneficiary, 3, gender: "F")
 
     result = AggregateDataQuery.new(
       group_by_fields: [
-        V1::BeneficiaryStatsRequestSchema::FIELDS.fetch("gender")
+        BeneficiaryField.find("gender")
       ],
     ).apply(Contact.all)
 
@@ -35,9 +35,9 @@
 
     result = AggregateDataQuery.new(
       group_by_fields: [
-        V1::BeneficiaryStatsRequestSchema::FIELDS.fetch("iso_country_code"),
-        V1::BeneficiaryStatsRequestSchema::FIELDS.fetch("address.iso_region_code"),
-        V1::BeneficiaryStatsRequestSchema::FIELDS.fetch("address.administrative_division_level_2_code")
+        BeneficiaryField.find("iso_country_code"),
+        BeneficiaryField.find("address.iso_region_code"),
+        BeneficiaryField.find("address.administrative_division_level_2_code")
       ],
     ).apply(Contact.all)
 
@@ -72,12 +72,12 @@
 
     result = AggregateDataQuery.new(
       filter_fields: {
-        V1::BeneficiaryStatsRequestSchema::FIELDS.fetch("address.iso_region_code") => "KH-12"
+        BeneficiaryField.find("address.iso_region_code") => "KH-12"
       },
       group_by_fields: [
-        V1::BeneficiaryStatsRequestSchema::FIELDS.fetch("iso_country_code"),
-        V1::BeneficiaryStatsRequestSchema::FIELDS.fetch("address.iso_region_code"),
-        V1::BeneficiaryStatsRequestSchema::FIELDS.fetch("address.administrative_division_level_2_code")
+        BeneficiaryField.find("iso_country_code"),
+        BeneficiaryField.find("address.iso_region_code"),
+        BeneficiaryField.find("address.administrative_division_level_2_code")
       ],
     ).apply(Contact.all)
 
@@ -115,9 +115,9 @@
     expect {
       AggregateDataQuery.new(
         group_by_fields: [
-          V1::BeneficiaryStatsRequestSchema::FIELDS.fetch("iso_country_code"),
-          V1::BeneficiaryStatsRequestSchema::FIELDS.fetch("address.iso_region_code"),
-          V1::BeneficiaryStatsRequestSchema::FIELDS.fetch("address.administrative_division_level_2_code")
+          BeneficiaryField.find("iso_country_code"),
+          BeneficiaryField.find("address.iso_region_code"),
+          BeneficiaryField.find("address.administrative_division_level_2_code")
         ],
       ).apply(Contact.all)
     }.to raise_error(AggregateDataQuery::TooManyResultsError)

spec/request_schemas/v1/beneficiary_stats_request_schema_spec.rb

@@ -28,13 +28,13 @@ module V1
       ).output
 
       expect(result[:filter_fields]).to include(
-        BeneficiaryStatsRequestSchema::FIELDS.fetch("gender") => "M",
-        BeneficiaryStatsRequestSchema::FIELDS.fetch("iso_country_code") => "KH"
+        BeneficiaryField.find("gender") => "M",
+        BeneficiaryField.find("iso_country_code") => "KH"
       )
       expect(result[:group_by_fields]).to contain_exactly(
-        BeneficiaryStatsRequestSchema::FIELDS.fetch("iso_country_code"),
-        BeneficiaryStatsRequestSchema::FIELDS.fetch("gender"),
-            BeneficiaryStatsRequestSchema::FIELDS.fetch("address.iso_region_code")
+        BeneficiaryField.find("iso_country_code"),
+        BeneficiaryField.find("gender"),
+        BeneficiaryField.find("address.iso_region_code")
       )
     end