From a08c1f27a14ef9e4c1a16a0c9ae5c2aa4dd79b25 Mon Sep 17 00:00:00 2001
From: Arthur Campbell <arfa.camble@gmail.com>
Date: Wed, 25 Jan 2023 16:40:47 +0000
Subject: [PATCH] add hard validation that percentage owned after a staircasing
 transaction cannot be less than the percentage bought in that transaction,
 with associated tests

---
 .../pages/staircase_bought_value_check.rb     |  4 +--
 .../sales/financial_validations.rb            |  8 ++++++
 config/locales/en.yml                         |  3 +++
 .../sales/financial_validations_spec.rb       | 27 +++++++++++++++++++
 4 files changed, 40 insertions(+), 2 deletions(-)

diff --git a/app/models/form/sales/pages/staircase_bought_value_check.rb b/app/models/form/sales/pages/staircase_bought_value_check.rb
index 98762dff2..b7b8178ff 100644
--- a/app/models/form/sales/pages/staircase_bought_value_check.rb
+++ b/app/models/form/sales/pages/staircase_bought_value_check.rb
@@ -13,8 +13,8 @@ class Form::Sales::Pages::StaircaseBoughtValueCheck < ::Form::Page
         {
           "key" => "stairbought",
           "i18n_template" => "percentage",
-        }
-      ]
+        },
+      ],
     }
     @informative_text = {}
   end
diff --git a/app/models/validations/sales/financial_validations.rb b/app/models/validations/sales/financial_validations.rb
index 233f32b6b..b6b478478 100644
--- a/app/models/validations/sales/financial_validations.rb
+++ b/app/models/validations/sales/financial_validations.rb
@@ -27,4 +27,12 @@ module Validations::Sales::FinancialValidations
       record.errors.add :cashdis, I18n.t("validations.financial.cash_discount_invalid")
     end
   end
+
+  def validate_percentage_bought_not_greater_than_percentage_owned(record)
+    return unless record.stairbought && record.stairowned
+
+    if record.stairbought > record.stairowned
+      record.errors.add :stairowned, I18n.t("validations.financial.staircasing.percentage_bought_must_be_greater_than_percentage_owned")
+    end
+  end
 end
diff --git a/config/locales/en.yml b/config/locales/en.yml
index 1ec13a304..2775b77c6 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -277,6 +277,9 @@ en:
         out_of_range: "Household rent and other charges must be between %{min_chcharge} and %{max_chcharge} if paying %{period}"
         not_provided: "Enter how much rent and other charges the household pays %{period}"
       cash_discount_invalid: "Cash discount must be £0 - £999,999"
+      staircasing:
+        percentage_bought_must_be_greater_than_percentage_owned: "Total percentage buyer now owns must be more than percentage bought in this transaction"
+
     household:
       reasonpref:
         not_homeless: "Answer cannot be ‘homeless or about to lose their home’ as the tenant was not homeless immediately prior to this letting"
diff --git a/spec/models/validations/sales/financial_validations_spec.rb b/spec/models/validations/sales/financial_validations_spec.rb
index 4bc19afbe..38ccaced9 100644
--- a/spec/models/validations/sales/financial_validations_spec.rb
+++ b/spec/models/validations/sales/financial_validations_spec.rb
@@ -99,4 +99,31 @@ RSpec.describe Validations::Sales::FinancialValidations do
       expect(record.errors["cashdis"]).to be_empty
     end
   end
+
+  describe "#validate_percentage_bought_not_greater_than_percentage_owned" do
+    let(:record) { FactoryBot.create(:sales_log) }
+
+    it "does not add an error if the percentage bought is less than the percentage owned" do
+      record.stairbought = 20
+      record.stairowned = 40
+      financial_validator.validate_percentage_bought_not_greater_than_percentage_owned(record)
+      expect(record.errors["stairbought"]).to be_empty
+      expect(record.errors["stairowned"]).to be_empty
+    end
+
+    it "does not add an error if the percentage bought is equal to the percentage owned" do
+      record.stairbought = 30
+      record.stairowned = 30
+      financial_validator.validate_percentage_bought_not_greater_than_percentage_owned(record)
+      expect(record.errors["stairbought"]).to be_empty
+      expect(record.errors["stairowned"]).to be_empty
+    end
+
+    it "adds an error to stairowned and not stairbought if the percentage bought is more than the percentage owned" do
+      record.stairbought = 50
+      record.stairowned = 40
+      financial_validator.validate_percentage_bought_not_greater_than_percentage_owned(record)
+      expect(record.errors["stairowned"]).to include(match I18n.t("validations.financial.staircasing.percentage_bought_must_be_greater_than_percentage_owned"))
+    end
+  end
 end