Added few unit tests

.gitignore

@@ -1,4 +1,6 @@
 # Hide eclipse project data
 .buildpath
 .project
-.settings
+.settings
+vendor/
+composer.lock

composer.json

@@ -11,11 +11,17 @@
         }
     ],
     "require" : {
-        "doctrine/dbal": "2.*"
+        "doctrine/dbal": "^2.0"
     },
     "autoload": {
         "psr-0": {
             "DoctrineTimestamp": "lib"
         }
+    },
+    "autoload-dev": {
+        "psr-4": { "DoctrineTimestamp\\Tests\\": "tests/" }
+    },
+    "require-dev": {
+        "phpunit/phpunit": "^5.7"
     }
-}
+}

lib/DoctrineTimestamp/DBAL/Types/Timestamp.php

@@ -48,11 +48,15 @@ public function convertToDatabaseValue($value, AbstractPlatform $platform)
             return $value->getTimestamp();
         }
 
-        throw ConversionException::conversionFailedInvalidType(
-            $value,
-            $this->getName(),
-            ['null', 'DateTime']
-        );
+        if (is_callable('ConversionException::conversionFailedInvalidType')) {
+            throw ConversionException::conversionFailedInvalidType(
+                $value,
+                $this->getName(),
+                ['null', 'DateTime']
+            );
+        }
+
+        throw ConversionException::conversionFailed($value, $this->getName());
     }
 
     /**

phpunit.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<phpunit backupGlobals="false"
+         backupStaticAttributes="false"
+         colors="true"
+         processIsolation="false"
+         stopOnFailure="false"
+         failOnWarning="true"
+         bootstrap="./vendor/autoload.php"
+>
+    <testsuites>
+        <testsuite name="Test classes">
+            <directory suffix=".php">./tests/</directory>
+        </testsuite>
+    </testsuites>
+
+    <filter>
+        <whitelist addUncoveredFilesFromWhitelist="true">
+            <directory suffix=".php">lib/</directory>
+        </whitelist>
+    </filter>
+</phpunit>

tests/DBAL/Types/TimestampTest.php

@@ -0,0 +1,129 @@
+<?php
+
+namespace DoctrineTimestamp\Test\DBAL\Types;
+
+use DateTime;
+use DateTimeInterface;
+use Doctrine\DBAL\Types\Type;
+use PHPUnit\Framework\TestCase;
+use DoctrineTimestamp\DBAL\Types\Timestamp;
+use Doctrine\DBAL\Platforms\MySqlPlatform;
+
+class TimestampTest extends TestCase
+{
+    protected $type;
+
+    public function setUp()
+    {
+        if (!Type::hasType(Timestamp::TIMESTAMP)) {
+            Type::addType(Timestamp::TIMESTAMP, Timestamp::class);
+        }
+
+        $this->type = Type::getType(Timestamp::TIMESTAMP);
+    }
+
+    public function testGetName()
+    {
+        $this->assertEquals(
+            Timestamp::TIMESTAMP,
+            $this->type->getName()
+        );
+    }
+
+    public function testGetSqlDeclaration()
+    {
+        $platform = $this->createMock('Doctrine\DBAL\Platforms\AbstractPlatform');
+
+        $expected = 'some integer col definition';
+
+        $platform
+            ->expects($this->any())
+            ->method('getIntegerTypeDeclarationSQL')
+            ->will($this->returnValue($expected))
+        ;
+
+        $this->assertEquals(
+            $expected,
+            $this->type->getSqlDeclaration(array(), $platform)
+        );
+    }
+
+    public function testConvertToDatabaseValueWithNullReturnsNull()
+    {
+        $this->assertNull(
+            $this->type->convertToDatabaseValue(
+                null,
+                new MySqlPlatform()
+            )
+        );
+    }
+
+    /**
+     * @expectedException Doctrine\DBAL\Types\ConversionException
+     */
+    public function testConvertToDatabaseValueWithInvalidTypeThrowsException()
+    {
+        $this->type->convertToDatabaseValue(
+            'string',
+            new MySqlPlatform()
+        );
+    }
+
+    /**
+     * @dataProvider provideSamples
+     */
+    public function testConvertToDatabaseValue(DateTimeInterface $input, $expected)
+    {
+        $this->assertEquals(
+            $expected,
+            $this->type->convertToDatabaseValue(
+                $input,
+                new MySqlPlatform()
+            )
+        );
+    }
+
+    public function provideSamples()
+    {
+        return array(
+            array(
+                new DateTime('1970-01-01 00:00:00 UTC'),
+                0,
+            ),
+            array(
+                new DateTime('1970-01-01 00:00:00 +01:00'),
+                -3600,
+            ),
+            array(
+                new DateTime('1970-01-01 00:00:00 -01:00'),
+                3600,
+            ),
+        );
+    }
+
+    public function testConvertToPHPValueWithNullReturnsNull()
+    {
+        $this->assertNull(
+            $this->type->convertToPHPValue(
+                null,
+                new MySqlPlatform()
+            )
+        );
+    }
+
+    /**
+     * @dataProvider provideSamples
+     */
+    public function testConvertToPHPValue(DateTimeInterface $expected, $input)
+    {
+        $res = $this->type->convertToPHPValue(
+            $input,
+            new MySqlPlatform()
+        );
+
+        $this->assertEquals($expected->getTimestamp(), $res->getTimestamp());
+
+        $res = $res->setTimezone($expected->getTimezone());
+        $this->assertEquals($expected->format('c'), $res->format('c'));
+    }
+}