diff --git a/src/Processor/Processor.php b/src/Processor/Processor.php
index 17dec43..86915cf 100644
--- a/src/Processor/Processor.php
+++ b/src/Processor/Processor.php
@@ -11,6 +11,8 @@
 use scss_compass as CompassCompiler;
 
 /**
+ * @see   ProcessorTest
+ *
  * @since 0.1
  */
 class Processor
diff --git a/src/ScriptHandler.php b/src/ScriptHandler.php
index 3f204bb..d18fd87 100644
--- a/src/ScriptHandler.php
+++ b/src/ScriptHandler.php
@@ -5,6 +5,11 @@
 use Composer\Script\Event;
 use EM\CssCompiler\Processor\Processor;
 
+/**
+ * @see   ScriptHandlerTest
+ *
+ * @since 0.1
+ */
 class ScriptHandler
 {
     const CONFIG_MAIN_KEY          = 'css-compiler';
diff --git a/tests/phpunit/Processor/ProcessorTest.php b/tests/phpunit/Processor/ProcessorTest.php
index 47425a5..64a7f9a 100644
--- a/tests/phpunit/Processor/ProcessorTest.php
+++ b/tests/phpunit/Processor/ProcessorTest.php
@@ -28,10 +28,11 @@ protected function setUp()
     public function attachFiles()
     {
         $paths = [
+            static::getSharedFixturesDirectory() . '/less'             => 1,
             static::getSharedFixturesDirectory() . '/compass'          => 1,
-            static::getSharedFixturesDirectory() . '/scss'             => 4,
             static::getSharedFixturesDirectory() . '/scss/layout.scss' => 1,
-            static::getSharedFixturesDirectory()                       => 6
+            static::getSharedFixturesDirectory() . '/scss'             => 4,
+            static::getSharedFixturesDirectory()                       => 7
         ];
         foreach ($paths as $path => $expectedFiles) {
             $processor = new Processor($this->io);
@@ -61,6 +62,15 @@ public function processFileOnSCSS()
         $this->invokeProcessFileMethod('scss/layout.scss', '');
     }
 
+    /**
+     * @see Processor::processFile
+     * @test
+     */
+    public function processFileOnLESS()
+    {
+        $this->invokeProcessFileMethod('less/print.less', '');
+    }
+
     /**
      * @see Processor::processFile
      * @test
@@ -114,7 +124,7 @@ public function processFileExpectedException()
      * @see Processor::getFormatterClass
      * @test
      */
-    public function getFormatterClass()
+    public function getFormatterClassOnCorrect()
     {
         foreach (Processor::$supportedFormatters as $formatter) {
             $expected = 'Leafo\\ScssPhp\\Formatter\\' . ucfirst($formatter);
@@ -125,4 +135,38 @@ public function getFormatterClass()
             );
         }
     }
+
+    /**
+     * @see Processor::getFormatterClass
+     * @test
+     *
+     * @expectedException \InvalidArgumentException
+     */
+    public function getFormatterClassOnException()
+    {
+        $this->invokeMethod(new Processor($this->io), 'getFormatterClass', ['not-existing']);
+    }
+
+    /**
+     * @see Processor::fetchInputContextIntoFile
+     * @test
+     */
+    public function fetchInputContextIntoFileOnSuccess()
+    {
+        $file = new FileContainer(static::getSharedFixturesDirectory() . '/scss/layout.scss', '');
+        $this->invokeMethod(new Processor($this->io), 'fetchInputContextIntoFile', [$file]);
+
+        $this->assertNotNull($file->getInputContent());
+    }
+
+    /**
+     * @see Processor::fetchInputContextIntoFile
+     * @test
+     *
+     * @expectedException \EM\CssCompiler\Exception\FileException
+     */
+    public function fetchInputContextIntoFileOnException()
+    {
+        $this->invokeMethod(new Processor($this->io), 'fetchInputContextIntoFile', [new FileContainer('input', 'output')]);
+    }
 }
diff --git a/tests/shared-fixtures/less/print.less b/tests/shared-fixtures/less/print.less
new file mode 100644
index 0000000..66e54ab
--- /dev/null
+++ b/tests/shared-fixtures/less/print.less
@@ -0,0 +1,101 @@
+/*! Source: https://github.com/h5bp/html5-boilerplate/blob/master/src/css/main.css */
+
+// ==========================================================================
+// Print styles.
+// Inlined to avoid the additional HTTP request: h5bp.com/r
+// ==========================================================================
+
+@media print {
+    *,
+    *:before,
+    *:after {
+        background: transparent !important;
+        color: #000 !important; // Black prints faster: h5bp.com/s
+        box-shadow: none !important;
+        text-shadow: none !important;
+    }
+
+    a,
+    a:visited {
+        text-decoration: underline;
+    }
+
+    a[href]:after {
+        content: " (" attr(href) ")";
+    }
+
+    abbr[title]:after {
+        content: " (" attr(title) ")";
+    }
+
+    // Don't show links that are fragment identifiers,
+    // or use the `javascript:` pseudo protocol
+    a[href^="#"]:after,
+    a[href^="javascript:"]:after {
+        content: "";
+    }
+
+    pre,
+    blockquote {
+        border: 1px solid #999;
+        page-break-inside: avoid;
+    }
+
+    thead {
+        display: table-header-group; // h5bp.com/t
+    }
+
+    tr,
+    img {
+        page-break-inside: avoid;
+    }
+
+    img {
+        max-width: 100% !important;
+    }
+
+    p,
+    h2,
+    h3 {
+        orphans: 3;
+        widows: 3;
+    }
+
+    h2,
+    h3 {
+        page-break-after: avoid;
+    }
+
+    // Bootstrap specific changes start
+
+    // Bootstrap components
+    .navbar {
+        display: none;
+    }
+    .btn,
+    .dropup > .btn {
+        > .caret {
+            border-top-color: #000 !important;
+        }
+    }
+    .label {
+        border: 1px solid #000;
+    }
+
+    .table {
+        border-collapse: collapse !important;
+
+        td,
+        th {
+            background-color: #fff !important;
+        }
+    }
+    .table-bordered {
+        th,
+        td {
+            border: 1px solid #ddd !important;
+        }
+    }
+
+    // Bootstrap specific changes end
+}