Added SqlDocument::comment()

Author: janpecha

src/Helpers.php

@@ -40,4 +40,14 @@ public static function formatValue($value, IDriver $driver)
 
 			throw new InvalidArgumentException("Unsupported value type.");
 		}
+
+
+		/**
+		 * @param  string
+		 * @return string
+		 */
+		public static function normalizeNewLines($s)
+		{
+			return str_replace(array("\r\n", "\r"), "\n", $s);
+		}
 	}

src/SqlDocument.php

@@ -132,4 +132,16 @@ public function command($command)
 			$this->addStatement($statement);
 			return $statement;
 		}
+
+
+		/**
+		 * @param  string
+		 * @return Statements\Comment
+		 */
+		public function comment($comment)
+		{
+			$statement = new Statements\Comment($comment);
+			$this->addStatement($statement);
+			return $statement;
+		}
 	}

src/Statements/Comment.php

@@ -0,0 +1,32 @@
+<?php
+
+	namespace CzProject\SqlGenerator\Statements;
+
+	use CzProject\SqlGenerator\Helpers;
+	use CzProject\SqlGenerator\IDriver;
+	use CzProject\SqlGenerator\IStatement;
+
+
+	class Comment implements IStatement
+	{
+		/** @var string */
+		private $comment;
+
+
+		/**
+		 * @param  string
+		 */
+		public function __construct($comment)
+		{
+			$this->comment = $comment;
+		}
+
+
+		/**
+		 * @return string
+		 */
+		public function toSql(IDriver $driver)
+		{
+			return '-- ' . str_replace("\n", "\n-- ", Helpers::normalizeNewLines(trim($this->comment)));
+		}
+	}

tests/SqlGenerator/SqlDocument.comment.phpt

@@ -0,0 +1,30 @@
+<?php
+
+use CzProject\SqlGenerator\Drivers;
+use CzProject\SqlGenerator\SqlDocument;
+use CzProject\SqlGenerator\Statements\IndexDefinition;
+use Tester\Assert;
+
+require __DIR__ . '/../bootstrap.php';
+
+
+test(function () {
+
+	$sql = new SqlDocument;
+	$driver = new Drivers\MysqlDriver;
+
+	$sql->comment('inline comment');
+	$sql->comment("\tblock comment #1\nblock comment #2\n\nblock comment #3\n");
+
+	Assert::same(implode("\n", array(
+		'',
+		'-- inline comment',
+		'',
+		'-- block comment #1',
+		'-- block comment #2',
+		'-- ',
+		'-- block comment #3',
+		'',
+	)), $sql->toSql($driver));
+
+});