Add WriteLines to write multi-line text at the current indent [minor]

CLAUDE.md

@@ -82,7 +82,7 @@ The library is built around these types:
      caller's to dispose, its `NewLine` is never changed (the terminator lives on a private
      forwarding writer), and `IsBuffered`/`ToString()` only work over a `StringWriter`
    - Indentation control via `Indent()`, `Outdent()`, and `CurrentIndent` property
-   - Output methods: `Write()`, `WriteLine()`, `NewLine()`
+   - Output methods: `Write()`, `WriteLine()`, `WriteLines()` (multi-line text, every line indented), `NewLine()`
    - Implements `IDisposable` with proper resource cleanup
 
    **Line endings.** `IndentedTextWriter` terminates lines with `Environment.NewLine`;

CodeBlocker.Test/WriteLinesTests.cs

@@ -0,0 +1,98 @@
+// Copyright (c) 2023-2026 ktsu-dev contributors
+
+namespace CodeBlocker.Tests;
+
+using ktsu.CodeBlocker;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+
+/// <summary>
+/// Pins <see cref="CodeBlocker.WriteLines"/>: every line of a multi-line fragment lands at the
+/// current indent, line endings follow the writer, and a verbatim literal's value is left alone.
+/// </summary>
+[TestClass]
+public sealed class WriteLinesTests
+{
+	private const string Nl = CodeBlocker.DefaultNewLineString;
+
+	[TestMethod]
+	public void IndentsEveryLineOfAMultiLineFragment()
+	{
+		using CodeBlocker codeBlocker = CodeBlocker.Create();
+		using (new Scope(codeBlocker))
+		{
+			codeBlocker.WriteLines("int a = 1;\nint b = 2;\n");
+			codeBlocker.WriteLines("x();\n");
+			codeBlocker.WriteLine("y();");
+		}
+
+		Assert.AreEqual($"{{{Nl}\tint a = 1;{Nl}\tint b = 2;{Nl}\tx();{Nl}\ty();{Nl}}}{Nl}", codeBlocker.ToString());
+	}
+
+	[TestMethod]
+	public void NormalisesCrLfAndCrToTheWritersTerminator()
+	{
+		using CodeBlocker codeBlocker = CodeBlocker.Create(CodeBlocker.DefaultIndentString, NewLines.Lf);
+		codeBlocker.Indent();
+		codeBlocker.WriteLines("a();\r\nb();\rc();\r\n");
+
+		Assert.AreEqual("\ta();\n\tb();\n\tc();\n", codeBlocker.ToString());
+	}
+
+	[TestMethod]
+	public void LeavesAVerbatimLiteralsLinesAsWritten()
+	{
+		using CodeBlocker codeBlocker = CodeBlocker.Create();
+		codeBlocker.Indent();
+		codeBlocker.WriteLines("string s = @\"first\r\nsecond\";\nf();\n");
+
+		Assert.AreEqual($"\tstring s = @\"first\r\nsecond\";{Nl}\tf();{Nl}", codeBlocker.ToString());
+	}
+
+	[TestMethod]
+	public void KeepsBlankLinesFreeOfIndentation()
+	{
+		using CodeBlocker codeBlocker = CodeBlocker.Create();
+		codeBlocker.Indent();
+		codeBlocker.WriteLines("a();\n\nb();\n");
+
+		Assert.AreEqual($"\ta();{Nl}{Nl}\tb();{Nl}", codeBlocker.ToString());
+	}
+
+	[TestMethod]
+	public void LeavesTheLastLineOpenWhenTheFragmentHasNoTrailingBreak()
+	{
+		using CodeBlocker codeBlocker = CodeBlocker.Create();
+		codeBlocker.Indent();
+		codeBlocker.WriteLines("a();\nb(");
+		codeBlocker.Write("1);");
+		codeBlocker.NewLine();
+		codeBlocker.WriteLine("c();");
+
+		Assert.AreEqual($"\ta();{Nl}\tb(1);{Nl}\tc();{Nl}", codeBlocker.ToString());
+	}
+
+	[TestMethod]
+	public void EndsALineAlreadyUnderWayAtTheFirstBreak()
+	{
+		using CodeBlocker codeBlocker = CodeBlocker.Create();
+		codeBlocker.Indent();
+		codeBlocker.Write("int a = ");
+		codeBlocker.WriteLines("1;\nint b = 2;\n");
+
+		Assert.AreEqual($"\tint a = 1;{Nl}\tint b = 2;{Nl}", codeBlocker.ToString());
+	}
+
+	[TestMethod]
+	[DataRow(null)]
+	[DataRow("")]
+	public void WritesNothingForNullOrEmpty(string? fragment)
+	{
+		using CodeBlocker codeBlocker = CodeBlocker.Create();
+		codeBlocker.Indent();
+		codeBlocker.WriteLines(fragment!);
+		codeBlocker.NewLine();
+		codeBlocker.WriteLine("a();");
+
+		Assert.AreEqual($"{Nl}\ta();{Nl}", codeBlocker.ToString());
+	}
+}

CodeBlocker/CodeBlocker.cs

@@ -278,6 +278,73 @@ public void Write(string text)
 		isMidLine = true;
 	}
 
+	/// <summary>
+	/// Write text that may span several lines, indenting every line at the current level.
+	/// </summary>
+	/// <param name="fragment">The text to write. Writing <see langword="null"/> or an empty string does nothing.</param>
+	/// <remarks>
+	/// <para>
+	/// <see cref="WriteLine(string)"/> and <see cref="Write"/> indent only the first line of what they
+	/// are given, so a snippet from elsewhere (a doc block, a user-supplied fragment, another
+	/// generator's output) would land with every line after the first at column 0. This writes each
+	/// line separately instead, so every one picks up the current indentation.
+	/// </para>
+	/// <para>
+	/// The fragment is split at <c>\r\n</c>, <c>\n</c> and <c>\r</c>, and each line is ended with
+	/// <see cref="NewLineString"/>, so the output never mixes line endings. A line break inside a
+	/// verbatim string literal (<c>@"..."</c>, <c>$@"..."</c>) is part of the string's value rather
+	/// than the code's layout, so it is written exactly as given and the literal's continuation lines
+	/// get no indentation.
+	/// </para>
+	/// <para>
+	/// When the fragment ends in a line break, so does the output. When it does not, its last line is
+	/// left open, exactly as <see cref="Write"/> leaves it.
+	/// </para>
+	/// </remarks>
+	public void WriteLines(string fragment)
+	{
+		if (string.IsNullOrEmpty(fragment))
+		{
+			return;
+		}
+
+		bool[] inVerbatimText = Templates.VerbatimStringScanner.FindVerbatimText(fragment);
+		int lineStart = 0;
+		int position = 0;
+		while (position < fragment.Length)
+		{
+			char c = fragment[position];
+			if ((c != '\n' && c != '\r') || inVerbatimText[position])
+			{
+				position++;
+				continue;
+			}
+
+			WriteWholeLine(fragment[lineStart..position]);
+			bool isCrLf = c == '\r' && position + 1 < fragment.Length && fragment[position + 1] == '\n';
+			position += isCrLf ? 2 : 1;
+			lineStart = position;
+		}
+
+		Write(fragment[lineStart..]);
+	}
+
+	/// <summary>
+	/// Writes one line and ends it, keeping a blank line free of indentation.
+	/// </summary>
+	/// <param name="line">The line, without a terminator.</param>
+	private void WriteWholeLine(string line)
+	{
+		if (line.Length == 0)
+		{
+			NewLine();
+		}
+		else
+		{
+			WriteLine(line);
+		}
+	}
+
 	/// <summary>
 	/// Increase the indentation level.
 	/// </summary>

README.md

@@ -536,6 +536,7 @@ The main class for building indented code blocks.
 | `WriteLine()` | `void` | Writes an empty line with current indentation |
 | `Write(string text)` | `void` | Writes text without adding a new line |
 | `NewLine()` | `void` | Writes an empty line without indentation |
+| `WriteLines(string fragment)` | `void` | Writes text that may span several lines, indenting every line at the current level and ending each with `NewLineString`. A line break inside a verbatim string literal is left as written |
 | `Indent()` | `void` | Increases the indent level |
 | `Outdent()` | `void` | Decreases the indent level |
 | `ToString()` | `string` | Returns the generated code as a string |