fix(m2): fix repository tag model issue

YKanBan.Tests/Models/RgbColorTests.cs

@@ -0,0 +1,72 @@
+using YKanBan.Models;
+
+namespace YKanBan.Tests.Models;
+
+/// <summary>Tests for the RGB color value type and its #RRGGBB text conversions.</summary>
+[TestClass]
+public class RgbColorTests
+{
+    [TestMethod]
+    public void ParseExtractsComponents()
+    {
+        RgbColor color = RgbColor.Parse("#ff0a00");
+        Assert.AreEqual(new RgbColor(0xFF, 0x0A, 0x00), color);
+    }
+
+    [TestMethod]
+    public void ParseAcceptsUppercaseAndMixedCaseHex()
+    {
+        Assert.AreEqual(new RgbColor(0xAB, 0xCD, 0xEF), RgbColor.Parse("#ABCDEF"));
+        Assert.AreEqual(new RgbColor(0xAB, 0xCD, 0xEF), RgbColor.Parse("#aBcDeF"));
+    }
+
+    [TestMethod]
+    [DataRow("ff0000")]
+    [DataRow("#ff000")]
+    [DataRow("#ff00000")]
+    [DataRow("#gg0000")]
+    [DataRow("#ff 000")]
+    [DataRow(" #ff0000")]
+    [DataRow("#ff0000 ")]
+    [DataRow("#")]
+    [DataRow("")]
+    public void TryParseRejectsMalformedText(string text)
+    {
+        Assert.IsFalse(RgbColor.TryParse(text, out _));
+    }
+
+    [TestMethod]
+    public void TryParseRejectsNull()
+    {
+        Assert.IsFalse(RgbColor.TryParse(null, out _));
+    }
+
+    [TestMethod]
+    public void ParseThrowsFormatExceptionForMalformedText()
+    {
+        Assert.ThrowsExactly<FormatException>(() => RgbColor.Parse("red"));
+    }
+
+    [TestMethod]
+    public void ToStringProducesCanonicalLowercaseForm()
+    {
+        Assert.AreEqual("#ee0a0a", new RgbColor(0xEE, 0x0A, 0x0A).ToString());
+
+        // Uppercase input normalizes to the canonical lowercase output.
+        Assert.AreEqual("#ee0a0a", RgbColor.Parse("#EE0A0A").ToString());
+    }
+
+    [TestMethod]
+    public void EqualityComparesComponents()
+    {
+        Assert.AreEqual(RgbColor.Parse("#ff0000"), RgbColor.Parse("#FF0000"));
+        Assert.AreNotEqual(RgbColor.Parse("#ff0000"), RgbColor.Parse("#ff0001"));
+    }
+
+    [TestMethod]
+    public void TextRoundTripPreservesColor()
+    {
+        RgbColor original = new(0x12, 0x34, 0x56);
+        Assert.AreEqual(original, RgbColor.Parse(original.ToString()));
+    }
+}

YKanBan.Tests/Storage/Workspace/WorkspaceRepositoryTests.cs

@@ -235,7 +235,7 @@ public class WorkspaceRepositoryTests
         using var fixture = new RepositoryFixture();
         fixture.Clock = 2000;
 
-        TagModel result = fixture.Repository.UpdateTag(fixture.BugTagId, "bug", "#ff0000", "");
+        TagModel result = fixture.Repository.UpdateTag(fixture.BugTagId, "bug", RgbColor.Parse("#ff0000"), "");
 
         Assert.AreEqual("bug", result.Name);
         Assert.AreEqual(0, fixture.AppDb.GetWorkspaces().Count);
@@ -247,10 +247,10 @@ public class WorkspaceRepositoryTests
         using var fixture = new RepositoryFixture();
         fixture.Clock = 3000;
 
-        TagModel updated = fixture.Repository.UpdateTag(fixture.BugTagId, "defect", "#ee0a0a", "desc");
+        TagModel updated = fixture.Repository.UpdateTag(fixture.BugTagId, "defect", RgbColor.Parse("#ee0a0a"), "desc");
 
         Assert.AreEqual("defect", updated.Name);
-        Assert.AreEqual("#ee0a0a", updated.Color);
+        Assert.AreEqual(new RgbColor(0xEE, 0x0A, 0x0A), updated.Color);
         Assert.AreEqual("desc", updated.Description);
         Assert.AreEqual(3000L, fixture.LastEditedAt);
     }

YKanBan/Models/RgbColor.cs

@@ -0,0 +1,63 @@
+namespace YKanBan.Models;
+
+/// <summary>
+/// An RGB color without an alpha channel, stored as one byte per component
+/// — mirroring the color structures of WinForms, WPF and Avalonia minus
+/// the alpha byte. The type is total: every combination of components is
+/// valid, and all validation happens at the text boundary. Converts to and
+/// from the persisted "#RRGGBB" text form; ToString always produces the
+/// canonical lowercase form (e.g. "#ff0a00").
+/// </summary>
+public readonly record struct RgbColor(byte R, byte G, byte B)
+{
+    /// <summary>Parses a "#RRGGBB" text with case-insensitive hex digits.</summary>
+    /// <exception cref="FormatException">The text is not in #RRGGBB form.</exception>
+    public static RgbColor Parse(string text) =>
+        TryParse(text, out RgbColor color)
+            ? color
+            : throw new FormatException($"Not a valid #RRGGBB color: '{text}'.");
+
+    /// <summary>Attempts to parse a "#RRGGBB" text; no whitespace tolerance.</summary>
+    public static bool TryParse(string? text, out RgbColor color)
+    {
+        color = default;
+        if (text is not { Length: 7 } || text[0] != '#')
+        {
+            return false;
+        }
+
+        // Two hex digits per component: R, G, B.
+        if (TryHexPair(text, 1, out byte r) && TryHexPair(text, 3, out byte g) && TryHexPair(text, 5, out byte b))
+        {
+            color = new RgbColor(r, g, b);
+            return true;
+        }
+        return false;
+    }
+
+    /// <summary>Returns the canonical lowercase "#RRGGBB" form used by the database and exports.</summary>
+    public override string ToString() => $"#{R:x2}{G:x2}{B:x2}";
+
+    /// <summary>Parses exactly two hex digits into a byte value.</summary>
+    private static bool TryHexPair(string text, int start, out byte value)
+    {
+        value = 0;
+        int high = HexDigit(text[start]);
+        int low = HexDigit(text[start + 1]);
+        if (high < 0 || low < 0)
+        {
+            return false;
+        }
+        value = (byte)((high << 4) | low);
+        return true;
+    }
+
+    /// <summary>Converts one hex digit to its value; -1 for any other character.</summary>
+    private static int HexDigit(char character) => character switch
+    {
+        >= '0' and <= '9' => character - '0',
+        >= 'a' and <= 'f' => character - 'a' + 10,
+        >= 'A' and <= 'F' => character - 'A' + 10,
+        _ => -1,
+    };
+}

YKanBan/Models/TagModel.cs

@@ -3,6 +3,6 @@ namespace YKanBan.Models;
 /// <summary>A tag assignable to cards. Tags are never garbage-collected: unreferenced tags stay until deleted explicitly.</summary>
 /// <param name="Id">Row id.</param>
 /// <param name="Name">Arbitrary non-empty text; no charset or length rules.</param>
-/// <param name="Color">Fixed #RRGGBB form.</param>
+/// <param name="Color">The tag color; persisted as #RRGGBB text.</param>
 /// <param name="Description">Free-form description, possibly empty.</param>
-public sealed record TagModel(long Id, string Name, string Color, string Description);
+public sealed record TagModel(long Id, string Name, RgbColor Color, string Description);

YKanBan/Storage/Workspace/WorkspaceRepository.cs

@@ -145,7 +145,7 @@ public sealed class WorkspaceRepository : IDisposable
             }
             if (!reader.IsDBNull(6))
             {
-                tags.Add(new TagModel(reader.GetInt64(6), reader.GetString(7), reader.GetString(8), reader.GetString(9)));
+                tags.Add(new TagModel(reader.GetInt64(6), reader.GetString(7), RgbColor.Parse(reader.GetString(8)), reader.GetString(9)));
             }
         }
         return cards;
@@ -183,7 +183,7 @@ public sealed class WorkspaceRepository : IDisposable
             }
             if (!reader.IsDBNull(6))
             {
-                tags.Add(new TagModel(reader.GetInt64(6), reader.GetString(7), reader.GetString(8), reader.GetString(9)));
+                tags.Add(new TagModel(reader.GetInt64(6), reader.GetString(7), RgbColor.Parse(reader.GetString(8)), reader.GetString(9)));
             }
         }
         return card;
@@ -313,13 +313,13 @@ public sealed class WorkspaceRepository : IDisposable
     }
 
     /// <summary>Creates a tag.</summary>
-    /// <exception cref="SqliteException">The name is empty/not unique, or the color is not #RRGGBB.</exception>
-    public TagModel AddTag(string name, string color, string description)
+    /// <exception cref="SqliteException">The name is empty/not unique.</exception>
+    public TagModel AddTag(string name, RgbColor color, string description)
     {
         using var transaction = _connection.BeginTransaction();
         long id = ExecuteInsert(transaction,
             "INSERT INTO tags (name, color, description) VALUES ($name, $color, $description);",
-            ("$name", name), ("$color", color), ("$description", description));
+            ("$name", name), ("$color", color.ToString()), ("$description", description));
         transaction.Commit();
 
         TouchEdited();
@@ -328,8 +328,8 @@ public sealed class WorkspaceRepository : IDisposable
 
     /// <summary>Rewrites name, color and description; a no-change call writes nothing.</summary>
     /// <exception cref="InvalidOperationException">The tag does not exist.</exception>
-    /// <exception cref="SqliteException">The new name is empty/not unique, or the color is not #RRGGBB.</exception>
-    public TagModel UpdateTag(long tagId, string name, string color, string description)
+    /// <exception cref="SqliteException">The new name is empty/not unique.</exception>
+    public TagModel UpdateTag(long tagId, string name, RgbColor color, string description)
     {
         TagModel existing = GetTag(tagId)
             ?? throw new InvalidOperationException($"Tag {tagId} does not exist.");
@@ -343,7 +343,7 @@ public sealed class WorkspaceRepository : IDisposable
         using var command = CreateCommand(
             "UPDATE tags SET name = $name, color = $color, description = $description WHERE id = $id;");
         command.Parameters.AddWithValue("$name", name);
-        command.Parameters.AddWithValue("$color", color);
+        command.Parameters.AddWithValue("$color", color.ToString());
         command.Parameters.AddWithValue("$description", description);
         command.Parameters.AddWithValue("$id", tagId);
         command.ExecuteNonQuery();
@@ -394,9 +394,9 @@ public sealed class WorkspaceRepository : IDisposable
     private static ColumnModel ReadColumn(SqliteDataReader reader) =>
         new(reader.GetInt64(0), reader.GetString(1), reader.GetString(2), reader.GetInt64(3), reader.GetInt64(4));
 
-    /// <summary>Reads a tags row from the reader cursor.</summary>
+    /// <summary>Reads a tags row from the reader cursor; color text converts to components.</summary>
     private static TagModel ReadTag(SqliteDataReader reader) =>
-        new(reader.GetInt64(0), reader.GetString(1), reader.GetString(2), reader.GetString(3));
+        new(reader.GetInt64(0), reader.GetString(1), RgbColor.Parse(reader.GetString(2)), reader.GetString(3));
 
     /// <summary>Creates a command bound to this connection.</summary>
     private SqliteCommand CreateCommand(string sql, SqliteTransaction? transaction = null)