fix: cherry-pick commit duplication

When commits are cherry picked from another branch they will be reported
multiple times. Implement equality interface for WalrusCommit and filter
repo commits to Distinct() based on this rule. Commits are equal if they
are from the same local repo (by path, not just name) and have matching
shas.

Signed-off-by: Cory Todd <[email protected]>

Walrus.Core.Tests/MockRepoProvider.cs

@@ -78,6 +78,17 @@ public IEnumerable<WalrusRepository> GetRepositories(string rootDirectory, int s
                         AuthorEmail = "[email protected]",
                         RepoName = "project_2",
                         RepoPath = "/home/user/code/project_2"
+                    },
+                    // A cherry-pick
+                    new WalrusCommit
+                    {
+                        Branch = "feature",
+                        Message = "[bugfix] really fix issue #2252",
+                        Sha = "0335f9a11ec0c5f83c0f412ed49e816f815d9089",
+                        Timestamp = ConstantDateTimes.Today,
+                        AuthorEmail = "[email protected]",
+                        RepoName = "project_2",
+                        RepoPath = "/home/user/code/project_2"
                     }
                 })
             };

Walrus.Core/Repository/WalrusCommit.cs

@@ -42,6 +42,28 @@ public class WalrusCommit
         /// </summary>
         public DateTime Timestamp { get; init; }
 
+        /// <inheritdoc />
+        public override bool Equals(object? obj)
+        {
+            return Equals(obj as WalrusCommit);
+        }
+
+        /// <summary>
+        ///     Commits with the same sha from the same repo path are equal
+        /// </summary>
+        public bool Equals(WalrusCommit? other)
+        {
+            return other != null &&
+                Sha == other.Sha &&
+                RepoPath == other.RepoPath;
+        }
+
+        /// <inheritdoc />
+        public override int GetHashCode()
+        {
+            return HashCode.Combine(Sha, RepoPath);
+        }
+
         /// <inheritdoc />
         public override string ToString()
         {

Walrus.Core/WalrusService.cs

@@ -46,7 +46,9 @@ public IEnumerable<CommitGroup> QueryCommits(WalrusQuery query)
             var commits =
                 QueryRepositories(query)
                     .AsParallel()
-                    .SelectMany(r => r.Commits.Where(preparedQuery.IsMatch));
+                    .SelectMany(r => r.Commits
+                        .Distinct()
+                        .Where(preparedQuery.IsMatch));
 
             // Wrap GroupBy in a CommitGroup so we can have keys of different types
             var grouped = query.GroupBy switch