Fixing nits

Author: StanleyGoldman

src/GitHub.App/Services/PullRequestService.cs

@@ -149,11 +149,8 @@ public async Task<Page<PullRequestListItemModel>> ReadPullRequests(
                 item.CommentCount += item.Reviews.Sum(x => x.Count);
                 item.Reviews = null;
 
-                var hasCheckSuites = item.LastCommit.CheckSuites != null
-                                     && item.LastCommit.CheckSuites.Any();
-
-                var hasStatuses = item.LastCommit.Statuses != null
-                                  && item.LastCommit.Statuses.Any();
+                var hasCheckSuites = item.LastCommit?.CheckSuites.Any() ?? false;
+                var hasStatuses = item.LastCommit?.Statuses.Any() ?? false;
 
                 if (!hasCheckSuites && !hasStatuses)
                 {

src/GitHub.App/ViewModels/GitHubPane/PullRequestCheckViewModel.cs

@@ -103,7 +103,7 @@ public static IEnumerable<IPullRequestCheckViewModel> Build(IViewViewModelFactor
                     return pullRequestCheckViewModel;
                 }) ?? new PullRequestCheckViewModel[0];
 
-            return statuses.Union(checks).OrderBy(model => model.Title);
+            return statuses.Concat(checks).OrderBy(model => model.Title);
         }
 
         [ImportingConstructor]

src/GitHub.Exports/Models/PullRequestDetailModel.cs

@@ -95,11 +95,11 @@ public class PullRequestDetailModel
         /// <summary>
         /// Gets or sets a collection of pull request Checks Suites
         /// </summary>
-        public List<CheckSuiteModel> CheckSuites { get; set; }
+        public IReadOnlyList<CheckSuiteModel> CheckSuites { get; set; }
 
         /// <summary>
         /// Gets or sets a collection of pull request Statuses
         /// </summary>
-        public List<StatusModel> Statuses { get; set; }
+        public IReadOnlyList<StatusModel> Statuses { get; set; }
     }
 }