Fix: PG::NotNullViolation (MAYBE-RAILS-DP)

app/controllers/budget_categories_controller.rb

@@ -15,7 +15,7 @@ def show
     else
       @budget_category = Current.family.budget_categories.find(params[:id])
       @recent_transactions = @recent_transactions.joins("LEFT JOIN categories ON categories.id = account_transactions.category_id")
-                                                 .where("categories.id = ? OR categories.parent_id = ?", @budget_category.category.id, @budget_category.category.id)
+                                               .where("categories.id = ? OR categories.parent_id = ?", @budget_category.category.id, @budget_category.category.id)
     end
 
     @recent_transactions = @recent_transactions.order("account_entries.date DESC, ABS(account_entries.amount) DESC").take(3)
@@ -30,6 +30,8 @@ def update
 
   private
     def budget_category_params
-      params.require(:budget_category).permit(:budgeted_spending)
+      params.require(:budget_category).permit(:budgeted_spending).tap do |bc_params|
+        bc_params[:budgeted_spending] = 0.0 if bc_params[:budgeted_spending].blank?
+      end
     end
 end

spec/controllers/budget_categories_controller_spec.rb

@@ -0,0 +1,63 @@
+require 'rails_helper'
+
+RSpec.describe BudgetCategoriesController, type: :controller do
+  let(:family) { create(:family) }
+  let(:user) { create(:user, family: family) }
+  let(:budget) { create(:budget, family: family) }
+  let(:category) { create(:category, family: family) }
+  let(:budget_category) { create(:budget_category, budget: budget, category: category) }
+
+  before do
+    sign_in(user)
+  end
+
+  describe 'PATCH #update' do
+    context 'with valid parameters' do
+      it 'updates the budgeted_spending' do
+        patch :update, params: { 
+          id: budget_category.id, 
+          budget_id: budget.id, 
+          budget_category: { budgeted_spending: 100.0 }
+        }
+
+        expect(budget_category.reload.budgeted_spending).to eq(100.0)
+        expect(response).to redirect_to(budget_budget_categories_path(budget))
+      end
+
+      it 'sets budgeted_spending to 0.0 when blank' do
+        patch :update, params: { 
+          id: budget_category.id, 
+          budget_id: budget.id, 
+          budget_category: { budgeted_spending: '' }
+        }
+
+        expect(budget_category.reload.budgeted_spending).to eq(0.0)
+        expect(response).to redirect_to(budget_budget_categories_path(budget))
+      end
+
+      it 'sets budgeted_spending to 0.0 when nil' do
+        patch :update, params: { 
+          id: budget_category.id, 
+          budget_id: budget.id, 
+          budget_category: { budgeted_spending: nil }
+        }
+
+        expect(budget_category.reload.budgeted_spending).to eq(0.0)
+        expect(response).to redirect_to(budget_budget_categories_path(budget))
+      end
+    end
+
+    context 'with invalid parameters' do
+      it 'renders show with unprocessable_entity status when validation fails' do
+        patch :update, params: { 
+          id: budget_category.id, 
+          budget_id: budget.id, 
+          budget_category: { budgeted_spending: 'invalid' }
+        }
+
+        expect(response).to render_template(:show)
+        expect(response).to have_http_status(:unprocessable_entity)
+      end
+    end
+  end
+end