Add RemoveNoteLinks method to sanitize note links before Mastodon sync

Author: davidwei

src/HappyNotes.Common/StringExtensions.cs

@@ -11,6 +11,8 @@ public static partial class StringExtensions
     private static readonly Regex NoteId = _NoteId();
     private static readonly Regex ImagePattern = _ImagePattern();
     private static readonly Regex ImagesSuffixPattern = _ImagesSuffixPattern();
+    private static readonly Regex LeadingNoteLinks = _LeadingNoteLinks();
+    private static readonly Regex TrailingNoteLinks = _TrailingNoteLinks();
     private static readonly Converter MarkdownConverter = new();
 
     /// <summary>
@@ -31,6 +33,12 @@ public static partial class StringExtensions
     [GeneratedRegex(@"(?<=(?:^|[^\\]))@[1-9][0-9]{0,31}(?=[^\d]|$)", RegexOptions.Singleline)]
     private static partial Regex _NoteId();
 
+    [GeneratedRegex(@"^(?:@[1-9][0-9]{0,31}\s*)+", RegexOptions.Singleline)]
+    private static partial Regex _LeadingNoteLinks();
+
+    [GeneratedRegex(@"\s*(?:@[1-9][0-9]{0,31}\s*)+$", RegexOptions.Singleline)]
+    private static partial Regex _TrailingNoteLinks();
+
     public static bool IsLong(this string? str)
     {
         var content = str?.Trim() ?? string.Empty;
@@ -132,6 +140,19 @@ public static string RemoveImageReference(this string? markdownInput)
         return markdownInput;
     }
 
+    public static string RemoveNoteLinks(this string? text)
+    {
+        if (text is null) return string.Empty;
+
+        // Remove leading note links (@123 @456 at the start)
+        text = LeadingNoteLinks.Replace(text, string.Empty);
+
+        // Remove trailing note links (@123 @456 at the end)
+        text = TrailingNoteLinks.Replace(text, string.Empty);
+
+        return text.Trim();
+    }
+
     [GeneratedRegex(@"!\[(.*?)\]\((.*?)\)", RegexOptions.Compiled)]
     private static partial Regex _ImagePattern();
 

src/HappyNotes.Services/MastodonTootService.cs

@@ -24,6 +24,8 @@ public async Task<Status> SendTootAsync(string instanceUrl, string accessToken,
 
         try
         {
+            // Remove note links (@123) from beginning and end before sending to Mastodon
+            text = text.RemoveNoteLinks();
             var fullText = _GetFullText(text, isMarkdown);
             if (fullText.Length > Constants.MastodonTootLength)
             {
@@ -66,6 +68,7 @@ private async Task<Status> _SendLongTootAsPhotoAsync(string instanceUrl, string
         logger.LogDebug("Converting long text to image for {InstanceUrl}, textLength: {TextLength}",
             instanceUrl, longText.Length);
 
+        // Note: longText has already been sanitized by RemoveNoteLinks() in the caller
         var client = new MastodonClient(instanceUrl, accessToken);
         var filePath = Path.GetTempFileName();
 
@@ -113,6 +116,8 @@ public async Task<Status> EditTootAsync(
 
         try
         {
+            // Remove note links (@123) from beginning and end before editing on Mastodon
+            newText = newText.RemoveNoteLinks();
             var fullText = _GetFullText(newText, isMarkdown);
             if (fullText.Length > Constants.MastodonTootLength)
             {
@@ -226,6 +231,7 @@ private async Task<Status> _EditLongTootAsPhotoAsync(
         logger.LogDebug("Editing long toot as photo for {InstanceUrl}, tootId: {TootId}, textLength: {TextLength}",
             instanceUrl, tootId, longText.Length);
 
+        // Note: longText has already been sanitized by RemoveNoteLinks() in the caller
         try
         {
             var client = new MastodonClient(instanceUrl, accessToken);

tests/HappyNotes.Common.Tests/StringExtensionsTests.cs

@@ -133,4 +133,28 @@ public void IsHtmlTest(string input, bool expected)
         Assert.That(result, Is.EqualTo(expected));
     }
 
+    [TestCase("@123 This is content", "This is content")]
+    [TestCase("@123 @456 This is content", "This is content")]
+    [TestCase("This is content @123", "This is content")]
+    [TestCase("This is content @123 @456", "This is content")]
+    [TestCase("@123 This is content @456", "This is content")]
+    [TestCase("@123 @456 This is content @789", "This is content")]
+    [TestCase("This is content", "This is content")]
+    [TestCase("@123", "")]
+    [TestCase("@123 @456 @789", "")]
+    [TestCase(null, "")]
+    [TestCase("", "")]
+    [TestCase("This @123 is content", "This @123 is content")]
+    [TestCase(@"\@123 This is content", @"\@123 This is content")]
+    [TestCase("@123\nThis is content", "This is content")]
+    [TestCase("This is content\n@123", "This is content")]
+    public void RemoveNoteLinksTest(string input, string expected)
+    {
+        // Act
+        var result = input.RemoveNoteLinks();
+
+        // Assert
+        Assert.That(result, Is.EqualTo(expected));
+    }
+
 }

tests/HappyNotes.Services.Tests/MastodonSyncNoteServiceTests.cs

@@ -95,4 +95,49 @@ public async Task SyncNewNote_ShouldSyncNoteToMastodon(string fullContent, bool
             _mockSyncQueueService.Verify(s => s.EnqueueAsync(It.IsAny<string>(), It.IsAny<SyncTask<object>>()), Times.Never);
         }
     }
+
+    [TestCase("@123 This is content", "This is content")]
+    [TestCase("@123 @456 This is content", "This is content")]
+    [TestCase("This is content @123", "This is content")]
+    [TestCase("@123 This is content @456", "This is content")]
+    [TestCase("This @123 is content", "This @123 is content")]
+    public async Task SyncNewNote_WithNoteLinks_ShouldEnqueueWithOriginalContent(string fullContent, string expectedCleanContent)
+    {
+        // Arrange
+        var note = new Note
+        {
+            Id = 100,
+            UserId = 1,
+            IsPrivate = false,
+            TagList = []
+        };
+
+        var mastodonUserAccounts = new List<MastodonUserAccount>
+        {
+            new()
+            {
+                Id = 1,
+                UserId = 1,
+                AccessToken = TextEncryptionHelper.Encrypt("test token", "test_key"),
+                InstanceUrl = "https://mastodon.instance",
+                SyncType = MastodonSyncType.All
+            }
+        };
+
+        _mockMastodonUserAccountCacheService
+            .Setup(s => s.GetAsync(note.UserId))
+            .ReturnsAsync(mastodonUserAccounts);
+
+        // Act
+        await _mastodonSyncNoteService.SyncNewNote(note, fullContent);
+
+        // Assert - The original content should be enqueued (cleaning happens in MastodonTootService)
+        _mockSyncQueueService.Verify(s => s.EnqueueAsync("mastodon",
+            It.Is<SyncTask<MastodonSyncPayload>>(task =>
+                task.Action == "CREATE" &&
+                task.EntityId == note.Id &&
+                task.UserId == note.UserId &&
+                ((MastodonSyncPayload)task.Payload).FullContent == fullContent)),
+            Times.Once);
+    }
 }