Add null check to Tag

Author: asbjornu

src/GitVersion.LibGit2Sharp/Git/Tag.cs

@@ -1,3 +1,4 @@
+using GitVersion.Extensions;
 using GitVersion.Helpers;
 using LibGit2Sharp;
 
@@ -7,20 +8,17 @@ internal sealed class Tag : ITag
 {
     private static readonly LambdaEqualityHelper<ITag> equalityHelper = new(x => x.Name.Canonical);
     private static readonly LambdaKeyComparer<ITag, string> comparerHelper = new(x => x.Name.Canonical);
-
     private readonly LibGit2Sharp.Tag innerTag;
+
     internal Tag(LibGit2Sharp.Tag tag)
     {
-        this.innerTag = tag;
+        this.innerTag = tag.NotNull();
         Name = new ReferenceName(this.innerTag.CanonicalName);
     }
-    public ReferenceName Name { get; }
 
+    public ReferenceName Name { get; }
     public int CompareTo(ITag other) => comparerHelper.Compare(this, other);
     public bool Equals(ITag? other) => equalityHelper.Equals(this, other);
-    public override bool Equals(object obj) => Equals((obj as ITag));
-    public override int GetHashCode() => equalityHelper.GetHashCode(this);
-    public override string ToString() => Name.ToString();
     public string? TargetSha => this.innerTag.Target.Sha;
 
     public ICommit? PeeledTargetCommit()
@@ -34,4 +32,8 @@ internal Tag(LibGit2Sharp.Tag tag)
 
         return target is LibGit2Sharp.Commit commit ? new Commit(commit) : null;
     }
+
+    public override bool Equals(object obj) => Equals((obj as ITag));
+    public override int GetHashCode() => equalityHelper.GetHashCode(this);
+    public override string ToString() => Name.ToString();
 }