Address more PR feedback

test/Core.Test/Utilities/SpanExtensionsTests.cs

@@ -0,0 +1,52 @@
+using Bit.Core.Utilities;
+using Xunit;
+
+#nullable enable
+
+namespace Bit.Core.Test.Utilities;
+
+public class SpanExtensionsTests
+{
+    [Theory]
+    [InlineData(".", "", "")]
+    [InlineData("T.T", "T", "T")]
+    [InlineData("T.", "T", "")]
+    [InlineData(".T", "", "T")]
+    [InlineData("T.T.T", "T", "T.T")]
+    public void TrySplitBy_CanSplit_Success(string fullString, string firstPart, string secondPart)
+    {
+        var success = fullString.AsSpan().TrySplitBy('.', out var firstPartSpan, out var secondPartSpan);
+        Assert.True(success);
+        Assert.Equal(firstPart, firstPartSpan.ToString());
+        Assert.Equal(secondPart, secondPartSpan.ToString());
+    }
+
+    [Theory]
+    [InlineData("Test", '.')]
+    [InlineData("Other test", 'S')]
+    public void TrySplitBy_CanNotSplit_Success(string fullString, char splitChar)
+    {
+        var success = fullString.AsSpan().TrySplitBy(splitChar, out var splitChunk, out var rest);
+        Assert.False(success);
+        Assert.True(splitChunk.IsEmpty);
+        Assert.Equal(fullString, rest.ToString());
+    }
+
+    [Theory]
+    [InlineData("11111", '1', 5)]
+    [InlineData("Text", 'z', 0)]
+    [InlineData("1", '1', 1)]
+    public void Count_ReturnsCount(string text, char countChar, int expectedInstances)
+    {
+        Assert.Equal(expectedInstances, text.AsSpan().Count(countChar));
+    }
+
+    [Theory]
+    [InlineData(new [] {5, 4}, 5, 1)]
+    [InlineData(new [] { 1 }, 5, 0)]
+    [InlineData(new [] { 5, 5, 5}, 5, 3)]
+    public void CountIntegers_ReturnsCount(int[] array, int countNumber, int expectedInstances)
+    {
+        Assert.Equal(expectedInstances, ((ReadOnlySpan<int>)array.AsSpan()).Count(countNumber));
+    }
+}