City Merge was Broken (#735)

* keyword argument defaults need to be keyword-ized

* Regression test for city merge bug

app/controllers/cities_controller.rb

@@ -50,7 +50,7 @@ def create
   # PATCH/PUT /cities/1.json
   def update
     if params[:approval_action]
-      approver = CityApprover.new(@city)
+      approver = CityApprover.new(@city.id)
       case params[:approval_action]
       when "merge"
         approver.merge!(params[:merge_city_id])

app/services/city_approver.rb

@@ -25,7 +25,7 @@ def merge!(existing_city_id)
     existing = City.find(existing_city_id)
     approval_gate do
       User.where(home_city: @city.id).update_all(home_city_id: existing.id)
-      self.reject!(false)
+      self.reject!(mail_user: false)
       UserMailer.delay.notify_city_suggestor(@city, :merged)
     end
   end

spec/controllers/cities_controller_spec.rb

@@ -0,0 +1,38 @@
+require 'spec_helper'
+
+describe CitiesController do
+  before do
+    [:away_ye_waitlisted, :authenticate_user!, :authorized?].each do |s|
+      allow(controller).to receive(s).and_return true
+    end
+  end
+
+  describe '#update' do
+    let(:unapproved_city) { 
+      city = create(:city, :unapproved) 
+      (1..10).each { |i| create(:user, home_city: city) }
+      city
+    }
+
+    let(:merge_request) {
+      {
+        id: unapproved_city.city_code,
+        city: {id: unapproved_city.id},
+        merge_city_id: create(:city).id,
+        approval_action: "merge"
+      }
+    }
+
+    it 'should move all users from City A to City B upon merge' do
+      city_a = unapproved_city
+      city_a_users = city_a.users
+      city_b_id = merge_request[:merge_city_id]
+
+      patch :update, merge_request
+      expect(response).to redirect_to(city_path(city_a))
+      expect(city_a_users.map { 
+        |u| u.reload.home_city_id == city_b_id 
+      }.all?).to eq(true)
+    end
+  end
+end