Add customer update specs

spec/requests/customer/update_spec.rb

@@ -0,0 +1,53 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe 'PATCH - /customers/:id' do
+  let(:customer) { create(:customer) }
+  let(:url) { "/customers/#{customer.id}" }
+
+  context 'when the request is valid' do
+    it 'updates the customer' do
+      customer_params = { name: 'John Doe', limit: 1000 }
+
+      patch(url, params: { customer: customer_params })
+
+      expect(response).to have_http_status(:ok)
+      expect(response.parsed_body['message']).to eq('Customer updated!')
+    end
+
+    it 'updates the customer with the correct attributes' do
+      customer_params = { name: 'John Doe', limit: 1000 }
+
+      patch(url, params: { customer: customer_params })
+
+      customer.reload
+
+      expect(customer.name).to eq('John Doe')
+      expect(customer.limit).to eq(1000)
+    end
+  end
+
+  context 'when the request is invalid' do
+    it 'returns an error message if name is in use' do
+      jack = create(:customer, name: 'Jack Sparrow', limit: 1000)
+      create(:customer, name: 'Will', limit: 1000)
+
+      customer_params = { name: 'Will', limit: 1000 }
+
+      patch("/customers/#{jack.id}", params: { customer: customer_params })
+
+      expect(response).to have_http_status(:unprocessable_entity)
+      expect(response.parsed_body['error']).to eq('The name Will is already in use!')
+    end
+
+    it 'returns an error message if limit is less than 0' do
+      customer_params = { name: 'John Doe', limit: -1 }
+
+      patch(url, params: { customer: customer_params })
+
+      expect(response).to have_http_status(:unprocessable_entity)
+      expect(response.parsed_body['error']).to eq('Validation failed: Limit must be greater than 0')
+    end
+  end
+end