Added customized AppendLine() for StringBuilder

AMWD.Common.Tests/Extensions/StreamExtensionsTests.cs

@@ -7,6 +7,7 @@ using Microsoft.VisualStudio.TestTools.UnitTesting;
 namespace AMWD.Common.Tests.Extensions
 {
 	[TestClass]
+	[System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
 	public class StreamExtensionsTests
 	{
 		[TestMethod]

AMWD.Common.Tests/Extensions/StringExtensionsTests.cs

@@ -333,5 +333,21 @@ namespace AMWD.Common.Tests.Extensions
 			Assert.IsNull(hexDecodeNull);
 			Assert.AreEqual("", hexDecodeEmpty);
 		}
+
+		[TestMethod]
+		public void ShouldAddCustomLineTermination()
+		{
+			// arrange
+			string value = "abc";
+			var sb = new StringBuilder();
+
+			// act
+			sb.AppendLine(value, "\r");
+			sb.AppendLine(value, "\r");
+
+			// assert
+			Assert.AreEqual($"{value}\r{value}\r", sb.ToString());
+			Assert.IsFalse(sb.ToString().Contains('\n'));
+		}
 	}
 }