Add BundleColorMap tests

tests/ImageSharp.Tests/Formats/WebP/LosslessUtilsTests.cs

@@ -214,6 +214,62 @@ public class LosslessUtilsTests
         Assert.Equal(expectedResult1, actual1);
     }
 
+    [Fact]
+    public void BundleColorMap_WithXbitsZero_Works()
+    {
+        // arrange
+        byte[] row = { 238, 238, 238, 238, 238, 238, 240, 237, 240, 235, 223, 223, 218, 220, 226, 219, 220, 204, 218, 211, 218, 221, 254, 255 };
+        int xBits = 0;
+        uint[] actual = new uint[row.Length];
+        uint[] expected =
+        {
+            4278251008, 4278251008, 4278251008, 4278251008, 4278251008,
+            4278251008, 4278251520, 4278250752, 4278251520, 4278250240,
+            4278247168, 4278247168, 4278245888, 4278246400, 4278247936,
+            4278246144, 4278246400, 4278242304, 4278245888, 4278244096,
+            4278245888, 4278246656, 4278255104, 4278255360
+        };
+
+        // act
+        LosslessUtils.BundleColorMap(row, actual.Length, xBits, actual);
+
+        // assert
+        Assert.True(actual.SequenceEqual(expected));
+    }
+
+    [Fact]
+    public void BundleColorMap_WithXbitsNoneZero_Works()
+    {
+        // arrange
+        byte[] row =
+        {
+            2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
+            3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
+            2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
+            3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
+            1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+            3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
+            3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
+            3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3
+        };
+        int xBits = 2;
+        uint[] actual = new uint[row.Length];
+        uint[] expected =
+        {
+            4278233600, 4278233600, 4278233600, 4278233600, 4278255360, 4278255360, 4278255360, 4278255360, 4278233600, 4278233600, 4278233600, 4278233600,
+            4278255360, 4278255360, 4278255360, 4278255360, 4278211840, 4278211840, 4278211840, 4278211840, 4278255360, 4278255360, 4278255360, 4278255360,
+            4278255360, 4278255360, 4278255360, 4278255360, 4278255360, 4278255360, 4278255360, 4278206208, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
+        };
+
+        // act
+        LosslessUtils.BundleColorMap(row, actual.Length, xBits, actual);
+
+        // assert
+        Assert.True(actual.SequenceEqual(expected));
+    }
+
     [Fact]
     public void CombinedShannonEntropy_Works() => RunCombinedShannonEntropyTest();