Support squash merges by parsing all commits for PR references

Co-authored-by: Malcolmnixon <1863707+Malcolmnixon@users.noreply.github.com>

Author: Copilot

src/DemaConsulting.BuildMark/RepoConnectors/GitHubRepoConnector.cs

@@ -160,20 +160,23 @@ public override async Task<List<string>> GetPullRequestsBetweenTagsAsync(Version
             range = $"{fromTag}..{toRef}";
         }
 
-        // Get merge commits in range using git log
-        // Arguments: --oneline (one line per commit), --merges (only merge commits)
-        // Output format: "<short-hash> Merge pull request #<number> from <branch>"
-        var output = await RunCommandAsync("git", $"log --oneline --merges {range}");
+        // Get commits in range using git log
+        // Arguments: --oneline (one line per commit)
+        // Output format: "<short-hash> <commit message>"
+        // Parses both merge commits ("Merge pull request #<number>") and squash commits ("... (#<number>)")
+        var output = await RunCommandAsync("git", $"log --oneline {range}");
 
-        // Extract pull request numbers from merge commit messages
+        // Extract pull request numbers from commit messages
         // Each line is parsed for "#<number>" pattern to identify the PR
+        // This works for both traditional merge commits and squash/rebase commits
         var regex = NumberReferenceRegex();
 
         var pullRequests = output
             .Split('\n', StringSplitOptions.RemoveEmptyEntries)
             .Select(line => regex.Match(line))
             .Where(match => match.Success)
             .Select(match => match.Groups[1].Value)
+            .Distinct() // Remove duplicates in case a PR number appears in multiple commits
             .ToList();
 
         return pullRequests;

test/DemaConsulting.BuildMark.Tests/GitHubRepoConnectorTests.cs

@@ -135,7 +135,7 @@ public async Task GitHubRepoConnector_GetPullRequestsBetweenTagsAsync_ReturnsExp
 
         connector.AddCommandResult(
             "git",
-            "log --oneline --merges v1.0.0..v2.0.0",
+            "log --oneline v1.0.0..v2.0.0",
             "abc123 Merge pull request #10 from feature/x\ndef456 Merge pull request #11 from bugfix/y");
 
         // Act
@@ -163,7 +163,7 @@ public async Task GitHubRepoConnector_GetPullRequestsBetweenTagsAsync_HandlesNul
 
         connector.AddCommandResult(
             "git",
-            "log --oneline --merges v1.0.0",
+            "log --oneline v1.0.0",
             "abc123 Merge pull request #10 from feature/x");
 
         // Act
@@ -184,7 +184,7 @@ public async Task GitHubRepoConnector_GetPullRequestsBetweenTagsAsync_HandlesNul
         var connector = new TestableGitHubRepoConnector();
         connector.AddCommandResult(
             "git",
-            "log --oneline --merges v1.0.0..HEAD",
+            "log --oneline v1.0.0..HEAD",
             "abc123 Merge pull request #11 from feature/y");
 
         // Act
@@ -205,7 +205,7 @@ public async Task GitHubRepoConnector_GetPullRequestsBetweenTagsAsync_HandlesBot
         var connector = new TestableGitHubRepoConnector();
         connector.AddCommandResult(
             "git",
-            "log --oneline --merges HEAD",
+            "log --oneline HEAD",
             "abc123 Merge pull request #12 from feature/z");
 
         // Act
@@ -231,7 +231,7 @@ public async Task GitHubRepoConnector_GetPullRequestsBetweenTagsAsync_UsesHeadWh
         // Mock git log with HEAD instead of non-existent tag
         connector.AddCommandResult(
             "git",
-            "log --oneline --merges v1.0.0..HEAD",
+            "log --oneline v1.0.0..HEAD",
             "abc123 Merge pull request #15 from feature/new");
 
         // Act - using a version that doesn't exist as a tag
@@ -244,6 +244,31 @@ public async Task GitHubRepoConnector_GetPullRequestsBetweenTagsAsync_UsesHeadWh
         Assert.AreEqual("15", prs[0]);
     }
 
+    /// <summary>
+    ///     Test that GetPullRequestsBetweenTagsAsync handles squash merge commits.
+    /// </summary>
+    [TestMethod]
+    public async Task GitHubRepoConnector_GetPullRequestsBetweenTagsAsync_HandlesSquashMerges()
+    {
+        // Arrange
+        var connector = new TestableGitHubRepoConnector();
+        
+        // Mock git log with squash merge commits (PR number in parentheses)
+        connector.AddCommandResult(
+            "git",
+            "log --oneline HEAD",
+            "abc123 Fix bug with validation (#18)\ndef456 Add new feature (#19)\nghi789 Update documentation (#20)");
+
+        // Act
+        var prs = await connector.GetPullRequestsBetweenTagsAsync(null, null);
+
+        // Assert
+        Assert.HasCount(3, prs);
+        Assert.AreEqual("18", prs[0]);
+        Assert.AreEqual("19", prs[1]);
+        Assert.AreEqual("20", prs[2]);
+    }
+
     /// <summary>
     ///     Test that GetIssuesForPullRequestAsync returns expected issues.
     /// </summary>