Ignore a trailing line terminator in comment text [patch]

CodeBlocker.Test/CodeBlockerExtensionsTests.cs

@@ -65,6 +65,32 @@ public void AutoGeneratedHeaderWritesABlankCopyrightLineAsABareComment()
 			codeBlocker.ToString());
 	}
 
+	[TestMethod]
+	[DataRow("\n", DisplayName = "LF")]
+	[DataRow("\r\n", DisplayName = "CRLF")]
+	[DataRow("\r", DisplayName = "CR")]
+	[DataRow("\u0085", DisplayName = "NEL")]
+	[DataRow("\u2028", DisplayName = "LINE SEPARATOR")]
+	[DataRow("\u2029", DisplayName = "PARAGRAPH SEPARATOR")]
+	public void AutoGeneratedHeaderIgnoresATrailingLineTerminatorOnTheCopyright(string terminator)
+	{
+		using CodeBlocker codeBlocker = Create();
+
+		codeBlocker.WriteAutoGeneratedHeader($"Copyright (c) X{terminator}");
+
+		Assert.AreEqual("// Copyright (c) X\n// <auto-generated />\n\n", codeBlocker.ToString());
+	}
+
+	[TestMethod]
+	public void AutoGeneratedHeaderKeepsABlankLineBeforeATrailingLineTerminator()
+	{
+		using CodeBlocker codeBlocker = Create();
+
+		codeBlocker.WriteAutoGeneratedHeader("A\n\nB\n");
+
+		Assert.AreEqual("// A\n//\n// B\n// <auto-generated />\n\n", codeBlocker.ToString());
+	}
+
 	[TestMethod]
 	public void NullableDirectivesAreWrittenVerbatim()
 	{

CodeBlocker.Test/DocCommentTests.cs

@@ -56,6 +56,30 @@ public void AMultiLineSummaryPrefixesEveryLine()
 			Render(documentation));
 	}
 
+	[TestMethod]
+	[DataRow("\n", DisplayName = "LF")]
+	[DataRow("\r\n", DisplayName = "CRLF")]
+	[DataRow("\u2028", DisplayName = "LINE SEPARATOR")]
+	public void ASingleLineSummaryWithATrailingLineTerminatorStaysOnOneLine(string terminator) =>
+		Assert.AreEqual(
+			"/// <summary>Hello.</summary>\n",
+			Render(new DocComment { Summary = $"Hello.{terminator}" }));
+
+	[TestMethod]
+	public void AMultiLineSummaryWithATrailingLineTerminatorHasNoEmptyLine() =>
+		Assert.AreEqual(
+			"/// <summary>\n/// A\n/// B\n/// </summary>\n",
+			Render(new DocComment { Summary = "A\nB\n" }));
+
+	[TestMethod]
+	public void ANamedTagWithATrailingLineTerminatorStaysOnOneLine()
+	{
+		DocComment documentation = new();
+		documentation.Params.Add(new DocTag { Name = "a", Text = "The value.\n" });
+
+		Assert.AreEqual("/// <param name=\"a\">The value.</param>\n", Render(documentation));
+	}
+
 	[TestMethod]
 	public void ABlankLineInsideATagIsWrittenWithoutTrailingWhitespace()
 	{

CodeBlocker/LineTerminators.cs

@@ -23,9 +23,21 @@ internal static class LineTerminators
 	/// the comment and into the code.
 	/// </summary>
 	/// <param name="text">The text to split.</param>
-	/// <returns>The lines, without their terminators. Text with no terminator is a single line.</returns>
-	internal static string[] Split(string text) =>
-		text.Replace("\r\n", "\n").Split(Characters);
+	/// <returns>
+	/// The lines, without their terminators. Text with no terminator is a single line. A trailing
+	/// terminator leaves an empty tail, which is not a line of its own, so <c>"A\n"</c> is the one
+	/// line <c>A</c>; a blank line inside the text, as in <c>"A\n\nB"</c>, is kept.
+	/// </returns>
+	internal static string[] Split(string text)
+	{
+		string[] lines = text.Replace("\r\n", "\n").Split(Characters);
+		if (lines.Length > 1 && lines[^1].Length == 0)
+		{
+			Array.Resize(ref lines, lines.Length - 1);
+		}
+
+		return lines;
+	}
 
 	/// <summary>
 	/// Reports whether text contains any line terminator the C# compiler recognises.