Feat: Add ReadOnlySpan<char> extension methods for escaped character checks with tests

Author: AnnaSasDev

src/CodeOfChaos.Extensions/ReadOnlySpanOfCharExtensions.cs

@@ -0,0 +1,22 @@
+// ---------------------------------------------------------------------------------------------------------------------
+// Imports
+// ---------------------------------------------------------------------------------------------------------------------
+// ReSharper disable once CheckNamespace
+namespace System;
+// ---------------------------------------------------------------------------------------------------------------------
+// Code
+// ---------------------------------------------------------------------------------------------------------------------
+public static class ReadOnlySpanOfCharExtensions {
+    public static bool IsNotEscapedCharacterAtIndex(this scoped ReadOnlySpan<char> source, int atIndex) {
+        int backslashCount = 0;
+        for (int i = atIndex - 1; i >= 0 && source[i] is '\\'; i--) {
+            backslashCount++;
+        }
+        return backslashCount % 2 == 0;
+    }
+
+    public static bool IsEscapedCharacterAtIndex(this scoped ReadOnlySpan<char> source, int atIndex) {
+        return !IsNotEscapedCharacterAtIndex(source, atIndex);
+    }
+    
+}

tests/Tests.CodeOfChaos.Extensions/ReadOnlySpanOfCharExtensionsTests.cs

@@ -0,0 +1,44 @@
+// ---------------------------------------------------------------------------------------------------------------------
+// Imports
+// ---------------------------------------------------------------------------------------------------------------------
+namespace Tests.CodeOfChaos.Extensions;
+
+// ---------------------------------------------------------------------------------------------------------------------
+// Code
+// ---------------------------------------------------------------------------------------------------------------------
+public class ReadOnlySpanOfCharExtensionsTests {
+
+    [Test]
+    [Arguments("", 0, true)]
+    [Arguments("a", 0, true)]
+    [Arguments(@"a\", 0, true)]
+    [Arguments(@"a\b", 2, false)]
+    [Arguments(@"\a", 1, false)]
+    public async Task IsNotEscapedCharacterAtIndex_ShouldWork(string input, int index, bool expected) {
+        // Arrange
+        ReadOnlySpan<char> span = input.AsSpan();
+        
+        // Act
+        bool result = span.IsNotEscapedCharacterAtIndex(index);
+
+        // Assert
+        await Assert.That(result).IsEqualTo(expected);
+    }
+    
+    [Test]
+    [Arguments("", 0, false)]
+    [Arguments("a", 0, false)]
+    [Arguments(@"a\", 0, false)]
+    [Arguments(@"a\b", 2, true)]
+    [Arguments(@"\a", 1, true)]
+    public async Task IsEscapedCharacterAtIndex_ShouldWork(string input, int index, bool expected) {
+        // Arrange
+        ReadOnlySpan<char> span = input.AsSpan();
+        
+        // Act
+        bool result = span.IsEscapedCharacterAtIndex(index);
+
+        // Assert
+        await Assert.That(result).IsEqualTo(expected);
+    }
+}