Suppress changelog link when versions are not git tags

src/DemaConsulting.BuildMark/RepoConnectors/GitHubRepoConnector.cs

@@ -104,7 +104,7 @@ public override async Task<BuildInformation> GetBuildInformationAsync(Version? v
             : null;
 
         // Generate full changelog link for GitHub
-        var changelogLink = GenerateGitHubChangelogLink(owner, repo, fromVersion?.Tag, toVersion.Tag);
+        var changelogLink = GenerateGitHubChangelogLink(owner, repo, fromVersion?.Tag, toVersion.Tag, lookupData.BranchTagNames);
 
         // Create and return build information with all collected data
         return new BuildInformation(
@@ -135,7 +135,8 @@ internal sealed record LookupData(
         List<Release> BranchReleases,
         Dictionary<string, RepositoryTag> TagsByName,
         Dictionary<string, Release> TagToRelease,
-        List<Version> ReleaseVersions);
+        List<Version> ReleaseVersions,
+        HashSet<string> BranchTagNames);
 
     /// <summary>
     ///     Fetches all required data from GitHub API in parallel.
@@ -222,7 +223,8 @@ internal static LookupData BuildLookupData(GitHubData data)
             branchReleases,
             tagsByName,
             tagToRelease,
-            releaseVersions);
+            releaseVersions,
+            branchTagNames);
     }
 
     /// <summary>
@@ -731,15 +733,22 @@ internal static (string owner, string repo) ParseOwnerRepo(string path)
     /// <param name="repo">Repository name.</param>
     /// <param name="oldTag">Old tag name (null if from beginning).</param>
     /// <param name="newTag">New tag name.</param>
-    /// <returns>WebLink to GitHub compare page, or null if no baseline tag.</returns>
-    internal static WebLink? GenerateGitHubChangelogLink(string owner, string repo, string? oldTag, string newTag)
+    /// <param name="branchTagNames">Set of tag names on the current branch.</param>
+    /// <returns>WebLink to GitHub compare page, or null if no baseline tag or if tags not found in branch.</returns>
+    internal static WebLink? GenerateGitHubChangelogLink(string owner, string repo, string? oldTag, string newTag, HashSet<string> branchTagNames)
     {
         // Cannot generate comparison link without a baseline tag
         if (oldTag == null)
         {
             return null;
         }
 
+        // Suppress changelog link if either tag is not in the branch
+        if (!branchTagNames.Contains(oldTag) || !branchTagNames.Contains(newTag))
+        {
+            return null;
+        }
+
         // Build comparison label and URL
         var comparisonLabel = $"{oldTag}...{newTag}";
         var comparisonUrl = $"https://github.com/{owner}/{repo}/compare/{comparisonLabel}";

test/DemaConsulting.BuildMark.Tests/GitHubRepoConnectorTests.cs

@@ -288,8 +288,11 @@ public void GitHubRepoConnector_GetCommitsInRange_ToHashNotFound_ReturnsEmptyLis
     [TestMethod]
     public void GitHubRepoConnector_GenerateGitHubChangelogLink_ValidTags_ReturnsWebLink()
     {
+        // Arrange
+        var branchTagNames = new HashSet<string> { "v1.0.0", "v2.0.0" };
+
         // Act
-        var link = GitHubRepoConnector.GenerateGitHubChangelogLink("owner", "repo", "v1.0.0", "v2.0.0");
+        var link = GitHubRepoConnector.GenerateGitHubChangelogLink("owner", "repo", "v1.0.0", "v2.0.0", branchTagNames);
 
         // Assert
         Assert.IsNotNull(link);
@@ -303,8 +306,59 @@ public void GitHubRepoConnector_GenerateGitHubChangelogLink_ValidTags_ReturnsWeb
     [TestMethod]
     public void GitHubRepoConnector_GenerateGitHubChangelogLink_NullOldTag_ReturnsNull()
     {
+        // Arrange
+        var branchTagNames = new HashSet<string> { "v2.0.0" };
+
+        // Act
+        var link = GitHubRepoConnector.GenerateGitHubChangelogLink("owner", "repo", null, "v2.0.0", branchTagNames);
+
+        // Assert
+        Assert.IsNull(link);
+    }
+
+    /// <summary>
+    ///     Test that GenerateGitHubChangelogLink returns null when oldTag is not in branch tags.
+    /// </summary>
+    [TestMethod]
+    public void GitHubRepoConnector_GenerateGitHubChangelogLink_OldTagNotInBranch_ReturnsNull()
+    {
+        // Arrange
+        var branchTagNames = new HashSet<string> { "v2.0.0" };
+
         // Act
-        var link = GitHubRepoConnector.GenerateGitHubChangelogLink("owner", "repo", null, "v2.0.0");
+        var link = GitHubRepoConnector.GenerateGitHubChangelogLink("owner", "repo", "v1.0.0", "v2.0.0", branchTagNames);
+
+        // Assert
+        Assert.IsNull(link);
+    }
+
+    /// <summary>
+    ///     Test that GenerateGitHubChangelogLink returns null when newTag is not in branch tags.
+    /// </summary>
+    [TestMethod]
+    public void GitHubRepoConnector_GenerateGitHubChangelogLink_NewTagNotInBranch_ReturnsNull()
+    {
+        // Arrange
+        var branchTagNames = new HashSet<string> { "v1.0.0" };
+
+        // Act
+        var link = GitHubRepoConnector.GenerateGitHubChangelogLink("owner", "repo", "v1.0.0", "v2.0.0", branchTagNames);
+
+        // Assert
+        Assert.IsNull(link);
+    }
+
+    /// <summary>
+    ///     Test that GenerateGitHubChangelogLink returns null when neither tag is in branch tags.
+    /// </summary>
+    [TestMethod]
+    public void GitHubRepoConnector_GenerateGitHubChangelogLink_NoTagsInBranch_ReturnsNull()
+    {
+        // Arrange
+        var branchTagNames = new HashSet<string>();
+
+        // Act
+        var link = GitHubRepoConnector.GenerateGitHubChangelogLink("owner", "repo", "v1.0.0", "v2.0.0", branchTagNames);
 
         // Assert
         Assert.IsNull(link);
@@ -325,6 +379,7 @@ public void GitHubRepoConnector_DetermineTargetVersion_ProvidedVersion_ReturnsPr
             [],
             [],
             [],
+            [],
             []);
 
         // Act
@@ -349,6 +404,7 @@ public void GitHubRepoConnector_DetermineTargetVersion_NoVersionNoReleases_Throw
             [],
             [],
             [],
+            [],
             []);
 
         InvalidOperationException? caughtException = null;
@@ -386,6 +442,7 @@ public void GitHubRepoConnector_DetermineBaselineVersion_NoReleases_ReturnsNull(
             [],
             [],
             [],
+            [],
             []);
 
         // Act