add issues spec and user agent details to entities

lib/api/entities.rb

@@ -875,5 +875,11 @@ module API
         expose :dependencies, using: Dependency
       end
     end
+
+    class UserAgentDetail < Grape::Entity
+      expose :user_agent
+      expose :ip_address
+      expose :submitted
+    end
   end
 end

spec/requests/api/issues_spec.rb

@@ -1462,6 +1462,25 @@ describe API::Issues do
     end
   end
 
+  describe "GET /projects/:id/issues/:issue_iid/user_agent_detail" do
+    let(:user_agent_detail) { create(:user_agent_detail, subject: issue) }
+
+    it 'exposes known attributes' do
+      get api("/projects/#{project.id}/issues/#{issue.iid}/user_agent_detail", admin)
+
+      expect(response).to have_http_status(200)
+      expect(json_response['user_agent']).to eq(user_agent_detail.user_agent)
+      expect(json_response['ip_address']).to eq(user_agent_detail.ip_address)
+      expect(json_response['submitted']).to be false
+    end
+
+    it "returns unautorized for non-admin users" do
+      get api("/projects/#{project.id}/issues/#{issue.iid}/user_agent_detail", user)
+
+      expect(response).to have_http_status(403)
+    end
+  end
+
   def expect_paginated_array_response(size: nil)
     expect(response).to have_http_status(200)
     expect(response).to include_pagination_headers