diff --git a/src/Api/Jobs/AddCommentJob.php b/src/Api/Jobs/AddCommentJob.php
index 1475bc33..f6dc4fb7 100644
--- a/src/Api/Jobs/AddCommentJob.php
+++ b/src/Api/Jobs/AddCommentJob.php
@@ -5,13 +5,13 @@ class AddCommentJob extends AbstractJob
 	{
 		$user = Auth::getCurrentUser();
 		$post = PostModel::findById($this->getArgument(self::POST_ID));
-		$text = CommentModel::validateText($this->getArgument(self::TEXT));
+		$text = $this->getArgument(self::TEXT);
 
 		$comment = CommentModel::spawn();
 		$comment->setCommenter($user);
 		$comment->setPost($post);
-		$comment->commentDate = time();
-		$comment->text = $text;
+		$comment->setDateTime(time());
+		$comment->setText($text);
 
 		CommentModel::save($comment);
 		Logger::log('{user} commented on {post}', [
diff --git a/src/Api/Jobs/EditCommentJob.php b/src/Api/Jobs/EditCommentJob.php
index 7daa110c..8315bc2d 100644
--- a/src/Api/Jobs/EditCommentJob.php
+++ b/src/Api/Jobs/EditCommentJob.php
@@ -12,8 +12,8 @@ class EditCommentJob extends AbstractJob
 	{
 		$comment = $this->comment;
 
-		$comment->commentDate = time();
-		$comment->text = CommentModel::validateText($this->getArgument(self::TEXT));
+		$comment->setDateTime(time());
+		$comment->setText($this->getArgument(self::TEXT));
 
 		CommentModel::save($comment);
 		Logger::log('{user} edited comment in {post}', [
diff --git a/src/Api/Jobs/PreviewCommentJob.php b/src/Api/Jobs/PreviewCommentJob.php
index bb1ad195..068209fa 100644
--- a/src/Api/Jobs/PreviewCommentJob.php
+++ b/src/Api/Jobs/PreviewCommentJob.php
@@ -4,12 +4,17 @@ class PreviewCommentJob extends AbstractJob
 	public function execute()
 	{
 		$user = Auth::getCurrentUser();
-		$text = CommentModel::validateText($this->getArgument(self::TEXT));
+		$text = $this->getArgument(self::TEXT);
+		$post = PostModel::findById($this->getArgument(self::POST_ID));
 
 		$comment = CommentModel::spawn();
 		$comment->setCommenter($user);
-		$comment->commentDate = time();
-		$comment->text = $text;
+		$comment->setDateTime(time());
+		$comment->setText($text);
+		$comment->setPost($post);
+
+		$comment->validate();
+
 		return $comment;
 	}
 
@@ -20,7 +25,7 @@ class PreviewCommentJob extends AbstractJob
 
 	public function requiresAuthentication()
 	{
-		return true;
+		return false;
 	}
 
 	public function requiresConfirmedEmail()
diff --git a/src/Controllers/CommentController.php b/src/Controllers/CommentController.php
index aa670a0e..fc9314fa 100644
--- a/src/Controllers/CommentController.php
+++ b/src/Controllers/CommentController.php
@@ -19,10 +19,11 @@ class CommentController
 		$comment = Api::run(
 			new PreviewCommentJob(),
 			[
+				PreviewCommentJob::POST_ID => InputHelper::get('post-id'),
 				PreviewCommentJob::TEXT => InputHelper::get('text')
 			]);
 
-		getContext()->transport->textPreview = $comment->getText();
+		getContext()->transport->textPreview = $comment->getTextMarkdown();
 	}
 
 	public function addAction()
diff --git a/src/Models/CommentModel.php b/src/Models/CommentModel.php
index 37053956..41e94aa1 100644
--- a/src/Models/CommentModel.php
+++ b/src/Models/CommentModel.php
@@ -2,7 +2,7 @@
 use \Chibi\Sql as Sql;
 use \Chibi\Database as Database;
 
-class CommentModel extends AbstractCrudModel
+final class CommentModel extends AbstractCrudModel
 {
 	public static function getTableName()
 	{
@@ -12,7 +12,7 @@ class CommentModel extends AbstractCrudModel
 	public static function spawn()
 	{
 		$comment = new CommentEntity;
-		$comment->commentDate = time();
+		$comment->setDateTime(time());
 		return $comment;
 	}
 
@@ -25,10 +25,10 @@ class CommentModel extends AbstractCrudModel
 			self::forgeId($comment);
 
 			$bindings = [
-				'text' => $comment->text,
-				'post_id' => $comment->postId,
-				'comment_date' => $comment->commentDate,
-				'commenter_id' => $comment->commenterId];
+				'text' => $comment->getText(),
+				'post_id' => $comment->getPostId(),
+				'comment_date' => $comment->getDateTime(),
+				'commenter_id' => $comment->getCommenterId()];
 
 			$stmt = new Sql\UpdateStatement();
 			$stmt->setTable('comment');
@@ -74,7 +74,7 @@ class CommentModel extends AbstractCrudModel
 	public static function preloadCommenters($comments)
 	{
 		self::preloadOneToMany($comments,
-			function($comment) { return $comment->commenterId; },
+			function($comment) { return $comment->getCommenterId(); },
 			function($user) { return $user->getId(); },
 			function($userIds) { return UserModel::findByIds($userIds); },
 			function($comment, $user) { return $comment->setCache('commenter', $user); });
@@ -83,25 +83,9 @@ class CommentModel extends AbstractCrudModel
 	public static function preloadPosts($comments)
 	{
 		self::preloadOneToMany($comments,
-			function($comment) { return $comment->postId; },
+			function($comment) { return $comment->getPostId(); },
 			function($post) { return $post->getId(); },
 			function($postIds) { return PostModel::findByIds($postIds); },
 			function($comment, $post) { $comment->setCache('post', $post); });
 	}
-
-
-
-	public static function validateText($text)
-	{
-		$text = trim($text);
-		$config = getConfig();
-
-		if (strlen($text) < $config->comments->minLength)
-			throw new SimpleException('Comment must have at least %d characters', $config->comments->minLength);
-
-		if (strlen($text) > $config->comments->maxLength)
-			throw new SimpleException('Comment must have at most %d characters', $config->comments->maxLength);
-
-		return $text;
-	}
 }
diff --git a/src/Models/Entities/CommentEntity.php b/src/Models/Entities/CommentEntity.php
index 6a473763..5683b77b 100644
--- a/src/Models/Entities/CommentEntity.php
+++ b/src/Models/Entities/CommentEntity.php
@@ -1,48 +1,93 @@
 <?php
-class CommentEntity extends AbstractEntity implements IValidatable
+final class CommentEntity extends AbstractEntity implements IValidatable
 {
-	public $text;
-	public $postId;
-	public $commentDate;
-	public $commenterId;
+	protected $text;
+	protected $postId;
+	protected $commentDate;
+	protected $commenterId;
 
 	public function validate()
 	{
-		//todo
+		$text = trim($this->getText());
+		$config = getConfig();
+
+		if (strlen($text) < $config->comments->minLength)
+			throw new SimpleException('Comment must have at least %d characters', $config->comments->minLength);
+
+		if (strlen($text) > $config->comments->maxLength)
+			throw new SimpleException('Comment must have at most %d characters', $config->comments->maxLength);
+
+		if (!$this->getPostId())
+			throw new SimpleException('Trying to save comment that doesn\'t refer to any post');
+
+		if (!$this->getDateTime())
+			throw new SimpleException('Trying to save comment that has no creation date specified');
+
+		$this->setText($text);
 	}
 
 	public function getText()
 	{
-		return TextHelper::parseMarkdown($this->text);
+		return $this->text;
 	}
 
-	public function setPost($post)
+	public function getTextMarkdown()
 	{
-		$this->setCache('post', $post);
-		$this->postId = $post->id;
+		return TextHelper::parseMarkdown($this->getText());
 	}
 
-	public function setCommenter($user)
+	public function setText($text)
 	{
-		$this->setCache('commenter', $user);
-		$this->commenterId = $user ? $user->id : null;
+		$this->text = $text;
 	}
 
 	public function getPost()
 	{
 		if ($this->hasCache('post'))
 			return $this->getCache('post');
-		$post = PostModel::findById($this->postId);
+		$post = PostModel::findById($this->getPostId());
 		$this->setCache('post', $post);
 		return $post;
 	}
 
+	public function getPostId()
+	{
+		return $this->postId;
+	}
+
+	public function setPost($post)
+	{
+		$this->setCache('post', $post);
+		$this->postId = $post->getId();
+	}
+
+	public function getDateTime()
+	{
+		return $this->commentDate;
+	}
+
+	public function setDateTime($dateTime)
+	{
+		$this->commentDate = $dateTime;
+	}
+
 	public function getCommenter()
 	{
 		if ($this->hasCache('commenter'))
 			return $this->getCache('commenter');
-		$user = UserModel::findById($this->commenterId, false);
+		$user = UserModel::findById($this->getCommenterId(), false);
 		$this->setCache('commenter', $user);
 		return $user;
 	}
+
+	public function getCommenterId()
+	{
+		return $this->commenterId;
+	}
+
+	public function setCommenter($user)
+	{
+		$this->setCache('commenter', $user);
+		$this->commenterId = $user ? $user->getId() : null;
+	}
 }
diff --git a/src/Views/comment-edit.phtml b/src/Views/comment-edit.phtml
index ced63b85..c0be8960 100644
--- a/src/Views/comment-edit.phtml
+++ b/src/Views/comment-edit.phtml
@@ -16,7 +16,7 @@ Assets::addScript('comment-edit.js');
 
 	<div class="form-row text">
 		<div class="input-wrapper">
-			<textarea name="text" cols="50" rows="3"><?= $this->context->transport->comment->text ?></textarea>
+			<textarea name="text" cols="50" rows="3"><?= $this->context->transport->comment->getText() ?></textarea>
 		</div>
 	</div>
 
diff --git a/src/Views/comment-small.phtml b/src/Views/comment-small.phtml
index d1b1d463..e2f52f0f 100644
--- a/src/Views/comment-small.phtml
+++ b/src/Views/comment-small.phtml
@@ -32,8 +32,8 @@ Assets::addScript('comment-edit.js');
 				<?php endif ?>
 			</span>
 
-			<span class="date" title="<?= TextHelper::formatDate($this->context->comment->commentDate, true) ?>">
-				<?= TextHelper::formatDate($this->context->comment->commentDate, false) ?>
+			<span class="date" title="<?= TextHelper::formatDate($this->context->comment->getDateTime(), true) ?>">
+				<?= TextHelper::formatDate($this->context->comment->getDateTime(), false) ?>
 			</span>
 
 			<?php if (Access::check(new Privilege(
@@ -64,7 +64,7 @@ Assets::addScript('comment-edit.js');
 		</div>
 
 		<div class="content">
-			<?= $this->context->comment->getText() ?>
+			<?= $this->context->comment->getTextMarkdown() ?>
 		</div>
 	</div>
 
diff --git a/tests/AbstractTest.php b/tests/AbstractTest.php
index 043b1c31..822ec9b8 100644
--- a/tests/AbstractTest.php
+++ b/tests/AbstractTest.php
@@ -35,7 +35,7 @@ class AbstractTest
 		$comment = CommentModel::spawn();
 		$comment->setPost($post);
 		$comment->setCommenter($owner);
-		$comment->text = 'test test';
+		$comment->setText('test test');
 		return CommentModel::save($comment);
 	}
 }
diff --git a/tests/CommentAddTest.php b/tests/CommentAddTest.php
index 670c0b7a..c8a5ca6b 100644
--- a/tests/CommentAddTest.php
+++ b/tests/CommentAddTest.php
@@ -14,10 +14,10 @@ class CommentAddTest extends AbstractTest
 		});
 
 		$this->assert->areEqual(1, CommentModel::getCount());
-		$this->assert->areEqual($text, $comment->text);
+		$this->assert->areEqual($text, $comment->getText());
 		$this->assert->areEqual(Auth::getCurrentUser()->getId(), $comment->getCommenter()->getId());
 		$this->assert->areEqual(1, $comment->getPost()->getId());
-		$this->assert->isNotNull($comment->commentDate);
+		$this->assert->isNotNull($comment->getDateTime());
 		$this->assert->doesNotThrow(function() use ($comment)
 		{
 			CommentModel::findById($comment->getId());
@@ -101,7 +101,7 @@ class CommentAddTest extends AbstractTest
 			return $this->runApi($text);
 		});
 
-		$this->assert->areEqual($text, $comment->text);
+		$this->assert->areEqual($text, $comment->getText());
 		$this->assert->areEqual(Auth::getCurrentUser()->getId(), $comment->getCommenter()->getId());
 		$this->assert->areEqual(UserModel::getAnonymousName(), $comment->getCommenter()->getName());
 	}
diff --git a/tests/CommentEditTest.php b/tests/CommentEditTest.php
index 73a71f32..49e48022 100644
--- a/tests/CommentEditTest.php
+++ b/tests/CommentEditTest.php
@@ -11,10 +11,10 @@ class CommentEditTest extends AbstractTest
 			return $this->runApi($text);
 		});
 
-		$this->assert->areEqual($text, $comment->text);
+		$this->assert->areEqual($text, $comment->getText());
 		$this->assert->areEqual(Auth::getCurrentUser()->getId(), $comment->getCommenter()->getId());
 		$this->assert->areEqual(1, $comment->getPost()->getId());
-		$this->assert->isNotNull($comment->commentDate);
+		$this->assert->isNotNull($comment->getDateTime());
 		$this->assert->doesNotThrow(function() use ($comment)
 		{
 			CommentModel::findById($comment->getId());
diff --git a/tests/CommentPreviewTest.php b/tests/CommentPreviewTest.php
new file mode 100644
index 00000000..c72d2226
--- /dev/null
+++ b/tests/CommentPreviewTest.php
@@ -0,0 +1,103 @@
+<?php
+class CommentPreviewTest extends AbstractTest
+{
+	public function testPreview()
+	{
+		$this->prepare();
+
+		$text = 'alohaaaaaaa';
+		$comment = $this->assert->doesNotThrow(function() use ($text)
+		{
+			return $this->runApi($text);
+		});
+
+		$this->assert->areEqual(0, CommentModel::getCount());
+		$this->assert->areEqual($text, $comment->getText());
+		$this->assert->areEqual(Auth::getCurrentUser()->getId(), $comment->getCommenter()->getId());
+		$this->assert->isNotNull($comment->getDateTime());
+		$this->assert->throws(function() use ($comment)
+		{
+			CommentModel::findById($comment->getId());
+		}, 'Invalid comment ID');
+	}
+
+	public function testAlmostTooShortText()
+	{
+		$this->prepare();
+		$this->assert->doesNotThrow(function()
+		{
+			return $this->runApi(str_repeat('b', getConfig()->comments->minLength));
+		});
+	}
+
+	public function testAlmostTooLongText()
+	{
+		$this->prepare();
+		$this->assert->doesNotThrow(function()
+		{
+			return $this->runApi(str_repeat('b', getConfig()->comments->maxLength));
+		});
+	}
+
+	public function testTooShortText()
+	{
+		$this->prepare();
+		$this->assert->throws(function()
+		{
+			return $this->runApi(str_repeat('b', getConfig()->comments->minLength - 1));
+		}, 'Comment must have at least');
+	}
+
+	public function testTooLongText()
+	{
+		$this->prepare();
+		$this->assert->throws(function()
+		{
+			return $this->runApi(str_repeat('b', getConfig()->comments->maxLength + 1));
+		}, 'Comment must have at most');
+	}
+
+	public function testNoAuth()
+	{
+		$this->prepare();
+		Auth::setCurrentUser(null);
+
+		$this->assert->throws(function()
+		{
+			$this->assert->isFalse(Auth::isLoggedIn());
+			return $this->runApi('alohaaaaaaa');
+		}, 'Insufficient privileges');
+	}
+
+	public function testAccessDenial()
+	{
+		$this->prepare();
+
+		getConfig()->privileges->addComment = 'nobody';
+		Access::init();
+		$this->assert->isFalse(Access::check(new Privilege(Privilege::AddComment)));
+
+		$this->assert->throws(function()
+		{
+			return $this->runApi('alohaaaaaaa');
+		}, 'Insufficient privileges');
+	}
+
+
+	protected function runApi($text)
+	{
+		$post = $this->mockPost();
+
+		return Api::run(
+			new PreviewCommentJob(),
+			[
+				PreviewCommentJob::POST_ID => $post->getId(),
+				PreviewCommentJob::TEXT => $text,
+			]);
+	}
+
+	protected function prepare()
+	{
+		$this->login($this->mockUser());
+	}
+}