Add null check to CommitCollection

Author: asbjornu

src/GitVersion.LibGit2Sharp/Git/CommitCollection.cs

@@ -1,17 +1,22 @@
+using GitVersion.Extensions;
 using LibGit2Sharp;
 
 namespace GitVersion;
 
 internal sealed class CommitCollection : ICommitCollection
 {
     private readonly ICommitLog innerCollection;
-    internal CommitCollection(ICommitLog collection) => this.innerCollection = collection;
 
-    public IEnumerator<ICommit> GetEnumerator() => this.innerCollection.Select(commit => new Commit(commit)).GetEnumerator();
+    internal CommitCollection(ICommitLog collection) => this.innerCollection = collection.NotNull();
+
+    public IEnumerator<ICommit> GetEnumerator()
+        => this.innerCollection.Select(commit => new Commit(commit)).GetEnumerator();
 
     IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
 
-    public IEnumerable<ICommit> GetCommitsPriorTo(DateTimeOffset olderThan) => this.SkipWhile(c => c.When > olderThan);
+    public IEnumerable<ICommit> GetCommitsPriorTo(DateTimeOffset olderThan)
+        => this.SkipWhile(c => c.When > olderThan);
+
     public IEnumerable<ICommit> QueryBy(CommitFilter commitFilter)
     {
         static object? GetReacheableFrom(object? item) =>
@@ -24,13 +29,7 @@ public IEnumerable<ICommit> QueryBy(CommitFilter commitFilter)
 
         var includeReachableFrom = GetReacheableFrom(commitFilter.IncludeReachableFrom);
         var excludeReachableFrom = GetReacheableFrom(commitFilter.ExcludeReachableFrom);
-        var filter = new LibGit2Sharp.CommitFilter
-        {
-            IncludeReachableFrom = includeReachableFrom,
-            ExcludeReachableFrom = excludeReachableFrom,
-            FirstParentOnly = commitFilter.FirstParentOnly,
-            SortBy = (LibGit2Sharp.CommitSortStrategies)commitFilter.SortBy
-        };
+        var filter = new LibGit2Sharp.CommitFilter { IncludeReachableFrom = includeReachableFrom, ExcludeReachableFrom = excludeReachableFrom, FirstParentOnly = commitFilter.FirstParentOnly, SortBy = (LibGit2Sharp.CommitSortStrategies)commitFilter.SortBy };
         var commitLog = ((IQueryableCommitLog)this.innerCollection).QueryBy(filter);
         return new CommitCollection(commitLog);
     }