Write multiple Controller tests to check logic

This has been educational! I've added four tests to check for how the controller processes the member search journey. I'm happy with where it's got to, and it's meant I've had a chance to clarify my controller code.

Author: jonodrew

app/controllers/admin/member_search_controller.rb

@@ -4,8 +4,8 @@ def index
     @name = @params[:name]
     @members = @name.blank? ? Member.none : Member.find_members(@name).select(:id, :name, :surname, :pronouns)
     @callback_url = @params[:callback] || results_admin_member_search_index_path
-    if (@members.size == 1) && @callback_url.present?
-      query = { member_pick: { members: [@members.pluck(:id)] } }
+    if @members.size == 1
+      query = { member_pick: { members: [@members.first.id] } }
       query_string = query.to_query
       @callback_url = "#{@callback_url}?#{query_string}"
       redirect_to @callback_url and return

spec/controllers/admin/member_search_controller_spec.rb

@@ -0,0 +1,58 @@
+require 'spec_helper'
+
+RSpec.describe Admin::MemberSearchController, type: :controller do
+  let(:member) {Fabricate.build(:member)}
+
+  describe 'GET #index' do
+    context "when user is not logged in" do
+      before do
+        get :index
+      end
+      it "redirects to the home page" do
+        expect(response).to redirect_to(root_path)
+      end
+    end
+
+    context "when user is an admin" do
+      let(:fake_relation) { instance_double('ActiveRecord::Relation') }
+      let(:fake_juliet) { instance_double('Member', id: 1, name: 'Juliet', surname: 'Montague') }
+
+      before do
+        login_as_admin(member)
+        get :index
+      end
+      it "shows user the search page" do
+        expect(response).to have_http_status(:ok)
+      end
+
+      context "and when admin user searches for a single existing user" do
+        before do
+          allow(Member).to receive(:find_members).with('Juliet').and_return(fake_relation)
+          allow(fake_relation).to receive(:select).with(any_args).and_return([fake_juliet])
+          get :index, params: {member_search: {name: "Juliet", callback: root_path}}
+        end
+        it "redirects to the calling service" do
+          expect(response).to have_http_status(:found)
+
+          uri = URI.parse(response.location)
+          redirect_params = Rack::Utils.parse_nested_query(uri.query)
+
+          expect(redirect_params["member_pick"]["members"]).to eq(["1"])
+        end
+      end
+
+      context "and when an admin user searches and there are multiple results" do
+      let(:fake_romeo) { double('Member', id: 2, name: 'Romeo', surname: 'Capulet')}
+
+        before do
+          allow(Member).to receive(:find_members).with('e').and_return(fake_relation)
+          allow(fake_relation).to receive(:select).with(any_args).and_return([fake_juliet, fake_romeo])
+          get :index, params: {member_search: {name: 'e', callback: root_path}}
+        end
+        it "presents the found members on the index page" do
+          expect(response).to have_http_status(:ok)
+        end
+      end
+    end
+  end
+end