feat: add models and workspace repository layer

YKanBan.Tests/Models/RgbColorTests.cs

@@ -0,0 +1,77 @@
+using YKanBan.Models;
+
+namespace YKanBan.Tests.Models;
+
+/// <summary>
+/// Tests for the RGB color value type: component storage and the text
+/// boundary in both directions.
+/// </summary>
+[TestClass]
+public class RgbColorTests
+{
+    [TestMethod]
+    public void ParseSplitsComponents()
+    {
+        RgbColor color = RgbColor.Parse("#102030");
+        Assert.AreEqual((byte)0x10, color.R);
+        Assert.AreEqual((byte)0x20, color.G);
+        Assert.AreEqual((byte)0x30, color.B);
+    }
+
+    [TestMethod]
+    [DataRow("#a1B2c3")]
+    [DataRow("#A1B2C3")]
+    [DataRow("#a1b2c3")]
+    public void ParseIsCaseInsensitive(string text)
+    {
+        Assert.AreEqual(new RgbColor(0xA1, 0xB2, 0xC3), RgbColor.Parse(text));
+    }
+
+    [TestMethod]
+    [DataRow("")]
+    [DataRow("112233")]
+    [DataRow("#11223")]
+    [DataRow("#1122334")]
+    [DataRow("#GGGGGG")]
+    [DataRow("#12345g")]
+    [DataRow(" #112233")]
+    [DataRow("#112233 ")]
+    public void ParseRejectsMalformedText(string text)
+    {
+        Assert.ThrowsExactly<FormatException>(() => RgbColor.Parse(text));
+    }
+
+    [TestMethod]
+    public void TryParseRejectsNull()
+    {
+        Assert.IsFalse(RgbColor.TryParse(null, out RgbColor color));
+        Assert.AreEqual(default, color);
+    }
+
+    [TestMethod]
+    public void TryParseAcceptsValidText()
+    {
+        Assert.IsTrue(RgbColor.TryParse("#010203", out RgbColor color));
+        Assert.AreEqual(new RgbColor(1, 2, 3), color);
+    }
+
+    [TestMethod]
+    public void ToStringUsesCanonicalLowercase()
+    {
+        Assert.AreEqual("#ff0a00", new RgbColor(0xFF, 0x0A, 0x00).ToString());
+    }
+
+    [TestMethod]
+    public void TextRoundTrips()
+    {
+        var color = new RgbColor(0x12, 0xAB, 0xCD);
+        Assert.AreEqual(color, RgbColor.Parse(color.ToString()));
+    }
+
+    [TestMethod]
+    public void EqualityComparesComponents()
+    {
+        Assert.AreEqual(new RgbColor(1, 2, 3), new RgbColor(1, 2, 3));
+        Assert.AreNotEqual(new RgbColor(1, 2, 3), new RgbColor(1, 2, 4));
+    }
+}