added phpunit

.travis.yml

@@ -0,0 +1,11 @@
+language: php
+
+php:
+  - 5.6
+  - 7.0
+
+install: travis_retry composer install --no-interaction --prefer-source
+
+script: vendor/bin/phpunit tests --coverage-clover clover.xml --whitelist src
+
+after_script: bash <(curl -s https://codecov.io/bash)

phpunit.xml

@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<phpunit backupGlobals="false"
+         backupStaticAttributes="false"
+         bootstrap="vendor/autoload.php"
+         colors="true"
+         convertErrorsToExceptions="true"
+         convertNoticesToExceptions="true"
+         convertWarningsToExceptions="true"
+         processIsolation="false"
+         stopOnFailure="false"
+         syntaxCheck="false"
+        >
+    <filter>
+        <whitelist processUncoveredFilesFromWhitelist="true">
+            <directory suffix=".php">./src</directory>
+        </whitelist>
+    </filter>
+    <testsuites>
+        <testsuite name="php-qrcode test suite">
+			<file>tests/BitBufferTest.php</file>
+        </testsuite>
+    </testsuites>
+</phpunit>

tests/BitBufferTest.php

@@ -0,0 +1,48 @@
+<?php
+/**
+ * @filesource   BitBufferTest.php
+ * @created      08.02.2016
+ * @author       Smiley <smiley@chillerlan.net>
+ * @copyright    2015 Smiley
+ * @license      MIT
+ */
+
+use chillerlan\QRCode\BitBuffer;
+use chillerlan\QRCode\QRConst;
+
+class BitBufferTest extends PHPUnit_Framework_TestCase{
+
+	/**
+	 * @var \chillerlan\QRCode\BitBuffer
+	 */
+	protected $bitBuffer;
+
+	protected function setUp(){
+		$this->bitBuffer = new BitBuffer;
+	}
+
+	public function bitProvider(){
+		return [
+			[QRConst::MODE_NUMBER,    16],
+			[QRConst::MODE_ALPHANUM,  32],
+			[QRConst::MODE_BYTE,      64],
+			[QRConst::MODE_KANJI,    128],
+		];
+	}
+
+	/**
+	 * @dataProvider bitProvider
+	 */
+	public function testPut($data, $value){
+		$this->bitBuffer->put($data, 4);
+		$this->assertEquals($value, $this->bitBuffer->buffer[0]);
+		$this->assertEquals(4, $this->bitBuffer->length);
+	}
+
+	public function testClear(){
+		$this->bitBuffer->clear();
+		$this->assertEquals([], $this->bitBuffer->buffer);
+		$this->assertEquals(0, $this->bitBuffer->length);
+	}
+
+}