diff --git a/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/AsyncTest.php b/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/AsyncTest.php
new file mode 100644
index 00000000000..049869c357d
--- /dev/null
+++ b/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/AsyncTest.php
@@ -0,0 +1,85 @@
+<?php
+
+namespace Swagger\Client;
+
+use Swagger\Client\Api\PetApi;
+use Swagger\Client\Model\Pet;
+
+class AsyncTest extends \PHPUnit_Framework_TestCase
+{
+    /** @var PetApi */
+    private $api;
+
+    /** @var  int */
+    private $petId;
+
+    public function setUp()
+    {
+        $this->api = new Api\PetApi();
+
+        $this->petId = 10005;
+        $pet = new Model\Pet;
+        $pet->setId($this->petId);
+        $pet->setName("PHP Unit Test");
+        $pet->setPhotoUrls(array("http://test_php_unit_test.com"));
+        // new tag
+        $tag= new Model\Tag;
+        $tag->setId($this->petId); // use the same id as pet
+        $tag->setName("test php tag");
+        // new category
+        $category = new Model\Category;
+        $category->setId($this->petId); // use the same id as pet
+        $category->setName("test php category");
+
+        $pet->setTags(array($tag));
+        $pet->setCategory($category);
+
+        $pet_api = new Api\PetApi();
+        // add a new pet (model)
+        $add_response = $pet_api->addPet($pet);
+    }
+
+    public function testAsyncRequest()
+    {
+        $promise = $this->api->getPetByIdAsync(10005);
+
+        $promise2 = $this->api->getPetByIdAsync(10005);
+
+        $pet = $promise->wait();
+        $pet2 = $promise2->wait();
+        $this->assertInstanceOf(Pet::class, $pet);
+        $this->assertInstanceOf(Pet::class, $pet2);
+    }
+
+    public function testAsyncRequestWithHttpInfo()
+    {
+        $promise = $this->api->getPetByIdAsyncWithHttpInfo($this->petId);
+
+        list($pet, $status, $headers) = $promise->wait();
+        $this->assertEquals(200, $status);
+        $this->assertInternalType('array', $headers);
+        $this->assertInstanceOf(Pet::class, $pet);
+    }
+
+    public function testAsyncThrowingException()
+    {
+        $this->setExpectedException(ApiException::class);
+
+        $promise = $this->api->getPetByIdAsync(0);
+        $promise->wait();
+    }
+
+    public function testAsyncApiExceptionWithoutWaitIsNotThrown()
+    {
+        $promise = $this->api->getPetByIdAsync(0);
+        sleep(1);
+    }
+
+    public function testAsyncHttpInfoThrowingException()
+    {
+        $this->setExpectedException(ApiException::class);
+
+        $promise = $this->api->getPetByIdAsyncWithHttpInfo(0);
+        $promise->wait();
+    }
+}
diff --git a/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/AuthTest.php b/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/AuthTest.php
new file mode 100644
index 00000000000..d0204352558
--- /dev/null
+++ b/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/AuthTest.php
@@ -0,0 +1,62 @@
+<?php
+
+namespace Swagger\Client;
+
+use Swagger\Client\Api\FakeApi;
+use Swagger\Client\Api\PetApi;
+use Swagger\Client\Model\Pet;
+
+require_once __DIR__ . '/FakeHttpClient.php';
+
+class AuthTest extends \PHPUnit_Framework_TestCase
+{
+    public function testCustomApiKeyHeader()
+    {
+        $authConfig = new Configuration();
+        $authConfig->setApiKey('api_key', '123qwe');
+
+        $fakeHttpClient = new FakeHttpClient();
+        $api = new PetApi($fakeHttpClient, $authConfig);
+        $api->getPetById(123);
+
+        $headers = $fakeHttpClient->getLastRequest()->getHeaders();
+
+        $this->assertArrayHasKey('api_key', $headers);
+        $this->assertEquals(['123qwe'], $headers['api_key']);
+    }
+
+    public function testApiToken()
+    {
+        $authConfig = new Configuration();
+        $authConfig->setAccessToken('asd123');
+
+        $fakeHttpClient = new FakeHttpClient();
+        $api = new PetApi($fakeHttpClient, $authConfig);
+        $api->addPet(new Pet());
+
+        $headers = $fakeHttpClient->getLastRequest()->getHeaders();
+
+        $this->assertArrayHasKey('Authorization', $headers);
+        $this->assertEquals(['Bearer asd123'], $headers['Authorization']);
+    }
+
+    public function testBasicAuth()
+    {
+        $username = 'user';
+        $password = 'password';
+
+        $authConfig = new Configuration();
+        $authConfig->setUsername($username);
+        $authConfig->setPassword($password);
+
+        $fakeHttpClient = new FakeHttpClient();
+        $api = new FakeApi($fakeHttpClient, $authConfig);
+        $api->testEndpointParameters(123, 100.1, 'ASD_', 'ASD');
+
+        $headers = $fakeHttpClient->getLastRequest()->getHeaders();
+
+        $this->assertArrayHasKey('Authorization', $headers);
+        $encodedCredentials = base64_encode("$username:$password");
+        $this->assertEquals(["Basic $encodedCredentials"], $headers['Authorization']);
+    }
+}
diff --git a/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/DateTimeSerializerTest.php b/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/DateTimeSerializerTest.php
new file mode 100644
index 00000000000..cea8db4a067
--- /dev/null
+++ b/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/DateTimeSerializerTest.php
@@ -0,0 +1,34 @@
+<?php
+
+namespace Swagger\Client;
+
+use Swagger\Client\Model\FormatTest;
+
+class DateTimeSerializerTest extends \PHPUnit_Framework_TestCase
+{
+    public function testDateTimeSanitazion()
+    {
+        $dateTime = new \DateTime('April 30, 1973 17:05 CEST');
+
+        $input = new FormatTest([
+            'date_time' => $dateTime,
+        ]);
+
+        $data = ObjectSerializer::sanitizeForSerialization($input);
+
+        $this->assertEquals($data->dateTime, '1973-04-30T17:05:00+02:00');
+    }
+
+    public function testDateSanitazion()
+    {
+        $dateTime = new \DateTime('April 30, 1973 17:05 CEST');
+
+        $input = new FormatTest([
+            'date' => $dateTime,
+        ]);
+
+        $data = ObjectSerializer::sanitizeForSerialization($input);
+
+        $this->assertEquals($data->date, '1973-04-30');
+    }
+}
diff --git a/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/DebugTest.php b/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/DebugTest.php
new file mode 100644
index 00000000000..6eb9dacaffe
--- /dev/null
+++ b/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/DebugTest.php
@@ -0,0 +1,26 @@
+<?php
+namespace Swagger\Client;
+
+class DebugTest extends \PHPUnit_Framework_TestCase
+{
+    public function testEnableDebugOutput()
+    {
+        $this->expectOutputRegex('#GET /v2/pet/1 HTTP/1.1#');
+
+        $config = new Configuration();
+        $config->setDebug(true);
+        $api = new Api\PetApi(null, $config);
+        $api->getPetById(1);
+    }
+
+    public function testEnableDebugOutputAsync()
+    {
+        $this->expectOutputRegex('#GET /v2/pet/1 HTTP/1.1#');
+
+        $config = new Configuration();
+        $config->setDebug(true);
+        $api = new Api\PetApi(null, $config);
+        $promise = $api->getPetByIdAsync(1);
+        $promise->wait();
+    }
+}
diff --git a/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/EnumClassTest.php b/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/EnumClassTest.php
new file mode 100644
index 00000000000..7ba9d0552bb
--- /dev/null
+++ b/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/EnumClassTest.php
@@ -0,0 +1,15 @@
+<?php
+
+namespace Swagger\Client;
+
+use Swagger\Client\Model\EnumClass;
+
+class EnumClassTest extends \PHPUnit_Framework_TestCase
+{
+    public function testPossibleValues()
+    {
+        $this->assertSame(EnumClass::ABC, '_abc');
+        $this->assertSame(EnumClass::EFG, '-efg');
+        $this->assertSame(EnumClass::XYZ, '(xyz)');
+    }
+}
diff --git a/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/EnumTestTest.php b/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/EnumTestTest.php
new file mode 100644
index 00000000000..9e4ea589251
--- /dev/null
+++ b/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/EnumTestTest.php
@@ -0,0 +1,34 @@
+<?php
+
+namespace Swagger\Client;
+
+use Swagger\Client\Model\EnumTest;
+
+class EnumTestTest extends \PHPUnit_Framework_TestCase
+{
+    public function testPossibleValues()
+    {
+        $this->assertSame(EnumTest::ENUM_STRING_UPPER, "UPPER");
+        $this->assertSame(EnumTest::ENUM_STRING_LOWER, "lower");
+        $this->assertSame(EnumTest::ENUM_INTEGER_1, 1);
+        $this->assertSame(EnumTest::ENUM_INTEGER_MINUS_1, -1);
+        $this->assertSame(EnumTest::ENUM_NUMBER_1_DOT_1, 1.1);
+        $this->assertSame(EnumTest::ENUM_NUMBER_MINUS_1_DOT_2, -1.2);
+    }
+
+    public function testNonRequiredPropertyIsOptional()
+    {
+        $enum = new EnumTest([
+            'enum_string_required' => 'UPPER',
+        ]);
+        $this->assertSame([], $enum->listInvalidProperties());
+        $this->assertTrue($enum->valid());
+    }
+
+    public function testRequiredProperty()
+    {
+        $enum = new EnumTest();
+        $this->assertSame(["'enum_string_required' can't be null"], $enum->listInvalidProperties());
+        $this->assertFalse($enum->valid());
+    }
+}
diff --git a/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/ExceptionTest.php b/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/ExceptionTest.php
new file mode 100644
index 00000000000..29a0d5d7559
--- /dev/null
+++ b/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/ExceptionTest.php
@@ -0,0 +1,41 @@
+<?php
+
+namespace Swagger\Client;
+
+use GuzzleHttp\Client;
+
+class ExceptionTest extends \PHPUnit_Framework_TestCase
+{
+    /**
+     * @expectedException \Swagger\Client\ApiException
+     * @expectedExceptionCode 404
+     * @expectedExceptionMessage http://petstore.swagger.io/INVALID_URL/store/inventory
+     */
+    public function testNotFound()
+    {
+        $config = new Configuration();
+        $config->setHost('http://petstore.swagger.io/INVALID_URL');
+
+        $api = new Api\StoreApi(
+            new Client(),
+            $config
+        );
+        $api->getInventory();
+    }
+
+    /**
+     * @expectedException \Swagger\Client\ApiException
+     * @expectedExceptionMessage Could not resolve host
+     */
+    public function testWrongHost()
+    {
+        $config = new Configuration();
+        $config->setHost('http://wrong_host.zxc');
+
+        $api = new Api\StoreApi(
+            new Client(),
+            $config
+        );
+        $api->getInventory();
+    }
+}
diff --git a/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/FakeHttpClient.php b/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/FakeHttpClient.php
new file mode 100644
index 00000000000..abdfa7cf7c2
--- /dev/null
+++ b/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/FakeHttpClient.php
@@ -0,0 +1,69 @@
+<?php
+
+namespace Swagger\Client;
+
+use GuzzleHttp\ClientInterface;
+use GuzzleHttp\Exception\GuzzleException;
+use GuzzleHttp\Psr7\Response;
+use Psr\Http\Message\RequestInterface;
+use Psr\Http\Message\ResponseInterface;
+
+class FakeHttpClient implements ClientInterface
+{
+    /** @var  RequestInterface|null */
+    private $request;
+    /** @var  ResponseInterface|null */
+    private $response;
+
+    /**
+     * @return null|RequestInterface
+     */
+    public function getLastRequest()
+    {
+        return $this->request;
+    }
+
+    /**
+     * @param null|ResponseInterface $response
+     */
+    public function setResponse(ResponseInterface $response = null)
+    {
+        $this->response = $response;
+    }
+
+    /**
+     * Send an HTTP request.
+     *
+     * @param RequestInterface $request Request to send
+     * @param array $options Request options to apply to the given
+     *                                  request and to the transfer.
+     *
+     * @return ResponseInterface
+     * @throws GuzzleException
+     */
+    public function send(RequestInterface $request, array $options = [])
+    {
+        $this->request = $request;
+        return $this->response ?: new Response(200);
+    }
+
+    public function sendAsync(RequestInterface $request, array $options = [])
+    {
+        throw new \RuntimeException('not implemented');
+    }
+
+    public function request($method, $uri, array $options = [])
+    {
+        throw new \RuntimeException('not implemented');
+    }
+
+    public function requestAsync($method, $uri, array $options = [])
+    {
+        throw new \RuntimeException('not implemented');
+    }
+
+    public function getConfig($option = null)
+    {
+        throw new \RuntimeException('not implemented');
+    }
+}
\ No newline at end of file
diff --git a/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/HeaderSelectorTest.php b/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/HeaderSelectorTest.php
new file mode 100644
index 00000000000..7a89448f89e
--- /dev/null
+++ b/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/HeaderSelectorTest.php
@@ -0,0 +1,56 @@
+<?php
+
+namespace Swagger\Client;
+
+class HeaderSelectorTest extends \PHPUnit_Framework_TestCase
+{
+    public function testSelectingHeaders()
+    {
+        $selector = new HeaderSelector();
+        $headers = $selector->selectHeaders([
+            'application/xml',
+            'application/json'
+        ], []);
+        $this->assertSame('application/json', $headers['Accept']);
+
+        $headers = $selector->selectHeaders([], []);
+        $this->assertArrayNotHasKey('Accept', $headers);
+
+        $header = $selector->selectHeaders([
+            'application/yaml',
+            'application/xml'
+        ], []);
+        $this->assertSame('application/yaml,application/xml', $header['Accept']);
+
+        // test selectHeaderContentType
+        $headers = $selector->selectHeaders([], [
+            'application/xml',
+            'application/json'
+        ]);
+        $this->assertSame('application/json', $headers['Content-Type']);
+
+        $headers = $selector->selectHeaders([], []);
+        $this->assertSame('application/json', $headers['Content-Type']);
+        $headers = $selector->selectHeaders([], [
+            'application/yaml',
+            'application/xml'
+        ]);
+        $this->assertSame('application/yaml,application/xml', $headers['Content-Type']);
+    }
+
+    public function testSelectingHeadersForMultipartBody()
+    {
+        // test selectHeaderAccept
+        $selector = new HeaderSelector();
+        $headers = $selector->selectHeadersForMultipart([
+            'application/xml',
+            'application/json'
+        ]);
+        $this->assertSame('application/json', $headers['Accept']);
+        $this->assertArrayNotHasKey('Content-Type', $headers);
+
+        $headers = $selector->selectHeadersForMultipart([]);
+        $this->assertArrayNotHasKey('Accept', $headers);
+        $this->assertArrayNotHasKey('Content-Type', $headers);
+    }
+}
diff --git a/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/HeadersTest.php b/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/HeadersTest.php
new file mode 100644
index 00000000000..5431a912efe
--- /dev/null
+++ b/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/HeadersTest.php
@@ -0,0 +1,31 @@
+<?php
+
+namespace Swagger\Client;
+
+require_once __DIR__ . '/FakeHttpClient.php';
+
+class HeadersTest extends \PHPUnit_Framework_TestCase
+{
+    /** @var  FakeHttpClient */
+    private $fakeHttpClient;
+
+    public function setUp()
+    {
+        $this->fakeHttpClient = new FakeHttpClient();
+    }
+
+    public function testUserAgent()
+    {
+        $config = new Configuration();
+        $config->setUserAgent('value');
+        $api = new Api\PetApi($this->fakeHttpClient, $config);
+
+        $api->getPetById(3);
+
+        $request = $this->fakeHttpClient->getLastRequest();
+        $headers = $request->getHeaders();
+
+        $this->assertArrayHasKey('User-Agent', $headers);
+        $this->assertEquals(['value'], $headers['User-Agent']);
+    }
+}
diff --git a/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/ModelInheritanceTest.php b/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/ModelInheritanceTest.php
new file mode 100644
index 00000000000..658e60ba638
--- /dev/null
+++ b/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/ModelInheritanceTest.php
@@ -0,0 +1,96 @@
+<?php
+
+namespace Swagger\Client;
+
+use Swagger\Client\Model\Animal;
+use Swagger\Client\Model\AnimalFarm;
+use Swagger\Client\Model\Cat;
+use Swagger\Client\Model\Dog;
+
+/**
+ * Test that Dog properly inherit Animal
+ *
+ * @package Swagger\Client
+ */
+class ModelInheritanceTest extends \PHPUnit_Framework_TestCase
+{
+    /**
+     * test if default values works
+     */
+    public function testDefaultValues()
+    {
+        // add some animals to the farm to make sure the ArrayAccess
+        // interface works
+        $dog = new Dog();
+        $animal = new Animal();
+
+        // assert we can look up the animals in the farm by array
+        // indices (let's try a random order)
+        $this->assertSame('red', $dog->getColor());
+        $this->assertSame('red', $animal->getColor());
+    }
+
+    /**
+     * test inheritance in the model
+     */
+    public function testInheritance()
+    {
+        $newDog = new Dog;
+        // the object should be an instance of the derived class
+        $this->assertInstanceOf(Dog::class, $newDog);
+        // the object should also be an instance of the parent class
+        $this->assertInstanceOf(Animal::class, $newDog);
+    }
+
+    /**
+     * test inheritance constructor is working with data initialization
+     */
+    public function testInheritanceConstructorDataInitialization()
+    {
+        // initialize the object with data in the constructor
+        $data = [
+            'class_name' => 'Dog',
+            'breed' => 'Great Dane',
+        ];
+        $newDog = new Dog($data);
+
+        // the property on the derived class should be set
+        $this->assertSame('Great Dane', $newDog->getBreed());
+        // the property on the parent class should be set
+        $this->assertSame('Dog', $newDog->getClassName());
+    }
+
+    /**
+     * test if discriminator is initialized automatically
+     */
+    public function testDiscriminatorInitialization()
+    {
+        $newDog = new Dog();
+        $this->assertSame('Dog', $newDog->getClassName());
+    }
+
+    /**
+     * test if ArrayAccess interface works
+     */
+    public function testArrayStuff()
+    {
+        // create an AnimalFarm which is an object implementing the ArrayAccess interface
+        $farm = new AnimalFarm();
+
+        // add some animals to the farm to make sure the ArrayAccess interface works
+        $farm[] = new Dog();
+        $farm[] = new Cat();
+        $farm[] = new Animal();
+
+        // assert we can look up the animals in the farm by array indices (let's try a random order)
+        $this->assertInstanceOf(Cat::class, $farm[1]);
+        $this->assertInstanceOf(Dog::class, $farm[0]);
+        $this->assertInstanceOf(Animal::class, $farm[2]);
+
+        // let's try to `foreach` the animals in the farm and let's try to use the objects we loop through
+        foreach ($farm as $animal) {
+            $this->assertContains($animal->getClassName(), ['Dog', 'Cat', 'Animal']);
+            $this->assertInstanceOf('Swagger\Client\Model\Animal', $animal);
+        }
+    }
+}
diff --git a/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/ObjectSerializerTest.php b/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/ObjectSerializerTest.php
new file mode 100644
index 00000000000..ce147d0e9e2
--- /dev/null
+++ b/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/ObjectSerializerTest.php
@@ -0,0 +1,25 @@
+<?php
+
+namespace Swagger\Client;
+
+// test object serializer
+class ObjectSerializerTest extends \PHPUnit_Framework_TestCase
+{
+    // test sanitizeFilename
+    public function testSanitizeFilename()
+    {
+        // initialize the API client
+        $s = new ObjectSerializer();
+
+        $this->assertSame("sun.gif", $s->sanitizeFilename("sun.gif"));
+        $this->assertSame("sun.gif", $s->sanitizeFilename("../sun.gif"));
+        $this->assertSame("sun.gif", $s->sanitizeFilename("/var/tmp/sun.gif"));
+        $this->assertSame("sun.gif", $s->sanitizeFilename("./sun.gif"));
+        
+        $this->assertSame("sun", $s->sanitizeFilename("sun"));
+        $this->assertSame("sun.gif", $s->sanitizeFilename("..\sun.gif"));
+        $this->assertSame("sun.gif", $s->sanitizeFilename("\var\tmp\sun.gif"));
+        $this->assertSame("sun.gif", $s->sanitizeFilename("c:\var\tmp\sun.gif"));
+        $this->assertSame("sun.gif", $s->sanitizeFilename(".\sun.gif"));
+    }
+}
diff --git a/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/OrderApiTest.php b/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/OrderApiTest.php
new file mode 100644
index 00000000000..8b5c8f7e499
--- /dev/null
+++ b/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/OrderApiTest.php
@@ -0,0 +1,133 @@
+<?php
+
+namespace Swagger\Client;
+
+class OrderApiTest extends \PHPUnit_Framework_TestCase
+{
+
+    // add a new pet (id 10005) to ensure the pet object is available for all the tests
+    public static function setUpBeforeClass()
+    {
+        // for error reporting (need to run with php5.3 to get no warning)
+        //ini_set('display_errors', 1);
+        //error_reporting(~0);
+    }
+  
+    // test get inventory
+    public function testOrderEnum()
+    {
+        $this->assertSame(Model\Order::STATUS_PLACED, "placed");
+        $this->assertSame(Model\Order::STATUS_APPROVED, "approved");
+    }
+
+    // test get inventory
+    public function testOrder()
+    {
+        // initialize the API client
+        $order = new Model\Order();
+  
+        $order->setStatus("placed");
+        $this->assertSame("placed", $order->getStatus());
+    }
+ 
+    /**
+     * @expectedException InvalidArgumentException
+     */
+    public function testOrderException()
+    {
+        // initialize the API client
+        $order = new Model\Order();
+        $order->setStatus("invalid_value");
+    }
+
+    // test deseralization of order
+    public function testDeserializationOfOrder()
+    {
+        $order_json = <<<ORDER
+{
+  "id": 10,
+  "petId": 20,
+  "quantity": 30,
+  "shipDate": "2015-08-22T07:13:36.613Z",
+  "status": "placed",
+  "complete": false
+}
+ORDER;
+        $order = ObjectSerializer::deserialize(
+            json_decode($order_json),
+            'Swagger\Client\Model\Order'
+        );
+        
+        $this->assertInstanceOf('Swagger\Client\Model\Order', $order);
+        $this->assertSame(10, $order->getId());
+        $this->assertSame(20, $order->getPetId());
+        $this->assertSame(30, $order->getQuantity());
+        $this->assertTrue(new \DateTime("2015-08-22T07:13:36.613Z") == $order->getShipDate());
+        $this->assertSame("placed", $order->getStatus());
+        $this->assertSame(false, $order->getComplete());
+    }
+  
+    // test deseralization of array of array of order
+    public function testDeserializationOfArrayOfArrayOfOrder()
+    {
+        $order_json = <<<ORDER
+[[{
+  "id": 10,
+  "petId": 20,
+  "quantity": 30,
+  "shipDate": "2015-08-22T07:13:36.613Z",
+  "status": "placed",
+  "complete": false
+}]]
+ORDER;
+        $order = ObjectSerializer::deserialize(
+            json_decode($order_json),
+            'Swagger\Client\Model\Order[][]'
+        );
+
+        $this->assertArrayHasKey(0, $order);
+        $this->assertArrayHasKey(0, $order[0]);
+        $_order = $order[0][0];
+        $this->assertInstanceOf('Swagger\Client\Model\Order', $_order);
+        $this->assertSame(10, $_order->getId());
+        $this->assertSame(20, $_order->getPetId());
+        $this->assertSame(30, $_order->getQuantity());
+        $this->assertTrue(new \DateTime("2015-08-22T07:13:36.613Z") == $_order->getShipDate());
+        $this->assertSame("placed", $_order->getStatus());
+        $this->assertSame(false, $_order->getComplete());
+    }
+
+    // test deseralization of map of map of order
+    public function testDeserializationOfMapOfMapOfOrder()
+    {
+        $order_json = <<<ORDER
+{
+  "test": {
+    "test2": {
+      "id": 10,
+      "petId": 20,
+      "quantity": 30,
+      "shipDate": "2015-08-22T07:13:36.613Z",
+      "status": "placed",
+      "complete": false
+    }
+  }
+}
+ORDER;
+        $order = ObjectSerializer::deserialize(
+            json_decode($order_json),
+            'map[string,map[string,\Swagger\Client\Model\Order]]'
+        );
+
+        $this->assertArrayHasKey('test', $order);
+        $this->assertArrayHasKey('test2', $order['test']);
+        $_order = $order['test']['test2'];
+        $this->assertInstanceOf('Swagger\Client\Model\Order', $_order);
+        $this->assertSame(10, $_order->getId());
+        $this->assertSame(20, $_order->getPetId());
+        $this->assertSame(30, $_order->getQuantity());
+        $this->assertTrue(new \DateTime("2015-08-22T07:13:36.613Z") == $_order->getShipDate());
+        $this->assertSame("placed", $_order->getStatus());
+        $this->assertSame(false, $_order->getComplete());
+    }
+}
diff --git a/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/OuterEnumTest.php b/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/OuterEnumTest.php
new file mode 100644
index 00000000000..d7d12d5cbb8
--- /dev/null
+++ b/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/OuterEnumTest.php
@@ -0,0 +1,94 @@
+<?php
+
+namespace Swagger\Client;
+
+use Swagger\Client\Model\EnumTest;
+use Swagger\Client\Model\OuterEnum;
+
+class OuterEnumTest extends \PHPUnit_Framework_TestCase
+{
+    public function testDeserialize()
+    {
+        $result = ObjectSerializer::deserialize(
+            "placed",
+            OuterEnum::class
+        );
+
+        $this->assertInternalType('string', $result);
+        $this->assertEquals('placed', $result);
+    }
+
+    public function testDeserializeInvalidValue()
+    {
+        $this->setExpectedException(\InvalidArgumentException::class, 'Invalid value for enum');
+
+        ObjectSerializer::deserialize(
+            "lkjfalgkdfjg",
+            OuterEnum::class
+        );
+    }
+
+    public function testDeserializeNested()
+    {
+        $json = '{
+            "enum_string": "UPPER",
+            "enum_integer": -1,
+            "enum_number": -1.2, 
+            "outerEnum": "approved"
+        }';
+
+        /** * @var EnumTest $result */
+        $result = ObjectSerializer::deserialize(
+            json_decode($json),
+            EnumTest::class
+        );
+
+        $this->assertInstanceOf(EnumTest::class, $result);
+        $this->assertEquals('approved', $result->getOuterEnum());
+    }
+
+    public function testSanitize()
+    {
+        $json = "placed";
+
+        $result = ObjectSerializer::sanitizeForSerialization(
+            $json
+        );
+
+        $this->assertInternalType('string', $result);
+    }
+
+    public function testSanitizeNested()
+    {
+        $input = new EnumTest([
+            'enum_string' => 'UPPER',
+            'enum_integer' => -1,
+            'enum_number' => -1.2,
+            'outer_enum' => 'approved'
+        ]);
+
+        $result = ObjectSerializer::sanitizeForSerialization(
+            $input
+        );
+
+        $this->assertInternalType('object', $result);
+        $this->assertInstanceOf(\stdClass::class, $result);
+
+        $this->assertInternalType('string', $result->outerEnum);
+        $this->assertEquals('approved', $result->outerEnum);
+    }
+
+    public function testSanitizeNestedInvalidValue()
+    {
+        $this->setExpectedException(\InvalidArgumentException::class, 'Invalid value for enum');
+
+        $input = new EnumTest([
+            'enum_string' => 'UPPER',
+            'enum_integer' => -1,
+            'enum_number' => -1.2,
+            'outer_enum' => 'invalid_value'
+        ]);
+
+        ObjectSerializer::sanitizeForSerialization($input);
+    }
+}
diff --git a/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/ParametersTest.php b/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/ParametersTest.php
new file mode 100644
index 00000000000..37877556d01
--- /dev/null
+++ b/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/ParametersTest.php
@@ -0,0 +1,65 @@
+<?php
+
+namespace Swagger\Client;
+
+use Swagger\Client\Api\FakeApi;
+use Swagger\Client\Api\UserApi;
+
+require_once __DIR__ . '/FakeHttpClient.php';
+
+class ParametersTest extends \PHPUnit_Framework_TestCase
+{
+    /** @var  FakeHttpClient */
+    private $fakeHttpClient;
+    /** @var  FakeApi */
+    private $fakeApi;
+    /** @var  UserApi */
+    private $userApi;
+
+    public function setUp()
+    {
+        $this->fakeHttpClient = new FakeHttpClient();
+        $this->fakeApi = new Api\FakeApi($this->fakeHttpClient);
+        $this->userApi = new Api\UserApi($this->fakeHttpClient);
+    }
+
+    public function testHeaderParam()
+    {
+        $this->fakeApi->testEnumParameters([], [], [], 'something');
+
+        $request = $this->fakeHttpClient->getLastRequest();
+        $headers = $request->getHeaders();
+
+        $this->assertArrayHasKey('enum_header_string', $headers);
+        $this->assertEquals(['something'], $headers['enum_header_string']);
+    }
+
+    public function testHeaderParamCollection()
+    {
+        $this->fakeApi->testEnumParameters([], [], ['string1', 'string2']);
+
+        $request = $this->fakeHttpClient->getLastRequest();
+        $headers = $request->getHeaders();
+
+        $this->assertArrayHasKey('enum_header_string_array', $headers);
+        $this->assertEquals(['string1,string2'], $headers['enum_header_string_array']);
+    }
+
+    public function testInlineAdditionalProperties()
+    {
+        $param = new \stdClass();
+        $param->foo = 'bar';
+        $this->fakeApi->testInlineAdditionalProperties($param);
+
+        $request = $this->fakeHttpClient->getLastRequest();
+        $this->assertSame('{"foo":"bar"}', $request->getBody()->getContents());
+    }
+
+//    missing example for collection path param in config
+//    public function testPathParamCollection()
+//    {
+//        $this->userApi->getUserByNameWithHttpInfo(['aa', 'bb']);
+//        $request = $this->fakeHttpClient->getLastRequest();
+//        $this->assertEquals('user/aa,bb', urldecode($request->getUri()->getPath()));
+//    }
+}
diff --git a/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/PetApiTest.php b/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/PetApiTest.php
new file mode 100644
index 00000000000..1cfad6aaeae
--- /dev/null
+++ b/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/PetApiTest.php
@@ -0,0 +1,404 @@
+<?php
+
+namespace Swagger\Client;
+
+use Swagger\Client\Api\PetApi;
+use Swagger\Client\Model\ApiResponse;
+use Swagger\Client\Model\Pet;
+
+class PetApiTest extends \PHPUnit_Framework_TestCase
+{
+
+    /** @var  PetApi */
+    private $api;
+
+    // add a new pet (id 10005) to ensure the pet object is available for all the tests
+    public static function setUpBeforeClass()
+    {
+        // increase memory limit to avoid fatal error due to findPetByStatus
+        // returning a lot of data
+        ini_set('memory_limit', '256M');
+
+        // enable debugging
+        //Configuration::$debug = true;
+
+        // new pet
+        $newPetId = 10005;
+        $newPet = new Model\Pet;
+        $newPet->setId($newPetId);
+        $newPet->setName("PHP Unit Test");
+        $newPet->setPhotoUrls(["http://test_php_unit_test.com"]);
+        // new tag
+        $tag = new Model\Tag;
+        $tag->setId($newPetId); // use the same id as pet
+        $tag->setName("test php tag");
+        // new category
+        $category = new Model\Category;
+        $category->setId($newPetId); // use the same id as pet
+        $category->setName("test php category");
+
+        $newPet->setTags(array($tag));
+        $newPet->setCategory($category);
+
+        $config = new Configuration();
+        $petApi = new Api\PetApi(null, $config);
+
+        // add a new pet (model)
+        list(, $status) = $petApi->addPetWithHttpInfo($newPet);
+        \PHPUnit_Framework_Assert::assertEquals(200, $status);
+    }
+
+    public function setUp()
+    {
+        $this->api = new Api\PetApi();
+    }
+
+    public function testGetPetById()
+    {
+        $petId = 10005;
+
+        $pet = $this->api->getPetById($petId);
+        $this->assertSame($pet->getId(), $petId);
+        $this->assertSame($pet->getName(), 'PHP Unit Test');
+        $this->assertSame($pet->getPhotoUrls()[0], 'http://test_php_unit_test.com');
+        $this->assertSame($pet->getCategory()->getId(), $petId);
+        $this->assertSame($pet->getCategory()->getName(), 'test php category');
+        $this->assertSame($pet->getTags()[0]->getId(), $petId);
+        $this->assertSame($pet->getTags()[0]->getName(), 'test php tag');
+    }
+
+    /**
+     * comment out as we've removed invalid endpoints from the spec, we'll introduce something
+     * similar in the future when we've time to update the petstore server
+     *
+     * // test getPetById with a Pet object (id 10005)
+     * public function testGetPetByIdInObject()
+     * {
+     * // initialize the API client without host
+     * $pet_id = 10005;  // ID of pet that needs to be fetched
+     * $pet_api = new Api\PetApi();
+     * $pet_api->getApiClient()->getConfig()->setApiKey('api_key', '111222333444555');
+     * // return Pet (inline model)
+     * $response = $pet_api->getPetByIdInObject($pet_id);
+     * $this->assertInstanceOf('Swagger\Client\Model\InlineResponse200', $response);
+     * $this->assertSame($response->getId(), $pet_id);
+     * $this->assertSame($response->getName(), 'PHP Unit Test');
+     * $this->assertSame($response->getPhotoUrls()[0], 'http://test_php_unit_test.com');
+     *
+     * // category is type "object"
+     * $this->assertInternalType('array', $response->getCategory());
+     * $this->assertSame($response->getCategory()['id'], $pet_id);
+     * $this->assertSame($response->getCategory()['name'], 'test php category');
+     *
+     * $this->assertSame($response->getTags()[0]->getId(), $pet_id);
+     * $this->assertSame($response->getTags()[0]->getName(), 'test php tag');
+     * }
+     */
+
+    // test getPetByIdWithHttpInfo with a Pet object (id 10005)
+    public function testGetPetByIdWithHttpInfo()
+    {
+        // initialize the API client without host
+        $petId = 10005;  // ID of pet that needs to be fetched
+
+        /** @var $pet Pet */
+        list($pet, $status_code, $response_headers) = $this->api->getPetByIdWithHttpInfo($petId);
+        $this->assertSame($pet->getId(), $petId);
+        $this->assertSame($pet->getName(), 'PHP Unit Test');
+        $this->assertSame($pet->getCategory()->getId(), $petId);
+        $this->assertSame($pet->getCategory()->getName(), 'test php category');
+        $this->assertSame($pet->getTags()[0]->getId(), $petId);
+        $this->assertSame($pet->getTags()[0]->getName(), 'test php tag');
+        $this->assertSame($status_code, 200);
+        $this->assertSame($response_headers['Content-Type'], ['application/json']);
+    }
+
+    public function testFindPetByStatus()
+    {
+        $response = $this->api->findPetsByStatus('available');
+        $this->assertGreaterThan(0, count($response)); // at least one object returned
+
+        $this->assertSame(get_class($response[0]), Pet::class); // verify the object is Pet
+        foreach ($response as $pet) {
+            $this->assertSame($pet['status'], 'available');
+        }
+
+        $response = $this->api->findPetsByStatus('unknown_and_incorrect_status');
+        $this->assertCount(0, $response);
+    }
+
+    public function testFindPetsByTags()
+    {
+        $response = $this->api->findPetsByTags('test php tag');
+        $this->assertGreaterThan(0, count($response)); // at least one object returned
+        $this->assertSame(get_class($response[0]), Pet::class); // verify the object is Pet
+
+        foreach ($response as $pet) {
+            $this->assertSame($pet['tags'][0]['name'], 'test php tag');
+        }
+
+        $response = $this->api->findPetsByTags('unknown_and_incorrect_tag');
+        $this->assertCount(0, $response);
+    }
+
+    public function testUpdatePet()
+    {
+        $petId = 10001;
+        $updatedPet = new Model\Pet;
+        $updatedPet->setId($petId);
+        $updatedPet->setName('updatePet');
+        $updatedPet->setStatus('pending');
+        $result = $this->api->updatePet($updatedPet);
+        $this->assertNull($result);
+
+        // verify updated Pet
+        $result = $this->api->getPetById($petId);
+        $this->assertSame($result->getId(), $petId);
+        $this->assertSame($result->getStatus(), 'pending');
+        $this->assertSame($result->getName(), 'updatePet');
+    }
+
+    // test updatePetWithFormWithHttpInfo and verify by the "name" of the response
+    public function testUpdatePetWithFormWithHttpInfo()
+    {
+        $petId = 10001;  // ID of pet that needs to be fetched
+
+        // update Pet (form)
+        list($update_response, $status_code, $http_headers) = $this->api->updatePetWithFormWithHttpInfo(
+            $petId,
+            'update pet with form with http info'
+        );
+        // return nothing (void)
+        $this->assertNull($update_response);
+        $this->assertSame($status_code, 200);
+        $this->assertSame($http_headers['Content-Type'], ['application/json']);
+        $response = $this->api->getPetById($petId);
+        $this->assertSame($response->getId(), $petId);
+        $this->assertSame($response->getName(), 'update pet with form with http info');
+    }
+
+    // test updatePetWithForm and verify by the "name" and "status" of the response
+    public function testUpdatePetWithForm()
+    {
+        $pet_id = 10001;  // ID of pet that needs to be fetched
+        $result = $this->api->updatePetWithForm($pet_id, 'update pet with form', 'sold');
+        // return nothing (void)
+        $this->assertNull($result);
+
+        $response = $this->api->getPetById($pet_id);
+        $this->assertSame($response->getId(), $pet_id);
+        $this->assertSame($response->getName(), 'update pet with form');
+        $this->assertSame($response->getStatus(), 'sold');
+    }
+
+    // test addPet and verify by the "id" and "name" of the response
+    public function testAddPet()
+    {
+        $new_pet_id = 10005;
+        $newPet = new Model\Pet;
+        $newPet->setId($new_pet_id);
+        $newPet->setName("PHP Unit Test 2");
+
+        // add a new pet (model)
+        $add_response = $this->api->addPet($newPet);
+        // return nothing (void)
+        $this->assertNull($add_response);
+
+        // verify added Pet
+        $response = $this->api->getPetById($new_pet_id);
+        $this->assertSame($response->getId(), $new_pet_id);
+        $this->assertSame($response->getName(), 'PHP Unit Test 2');
+    }
+
+    /*
+     * comment out as we've removed invalid endpoints from the spec, we'll introduce something
+     * similar in the future when we've time to update the petstore server
+     *
+    // test addPetUsingByteArray and verify by the "id" and "name" of the response
+    public function testAddPetUsingByteArray()
+    {
+        // initialize the API client
+        $config = (new Configuration())->setHost('http://petstore.swagger.io/v2');
+        $api_client = new ApiClient($config);
+
+        $new_pet_id = 10005;
+        $new_pet = new Model\Pet;
+        $new_pet->setId($new_pet_id);
+        $new_pet->setName("PHP Unit Test 3");
+        // new tag
+        $tag= new Model\Tag;
+        $tag->setId($new_pet_id); // use the same id as pet
+        $tag->setName("test php tag");
+        // new category
+        $category = new Model\Category;
+        $category->setId($new_pet_id); // use the same id as pet
+        $category->setName("test php category");
+  
+        $new_pet->setTags(array($tag));
+        $new_pet->setCategory($category);
+
+        $pet_api = new Api\PetApi($api_client);
+        // add a new pet (model)
+        $object_serializer = new ObjectSerializer();
+        $pet_json_string = json_encode($object_serializer->sanitizeForSerialization($new_pet));
+        $add_response = $pet_api->addPetUsingByteArray($pet_json_string);
+        // return nothing (void)
+        $this->assertSame($add_response, NULL);
+        // verify added Pet
+        $response = $pet_api->getPetById($new_pet_id);
+        $this->assertSame($response->getId(), $new_pet_id);
+        $this->assertSame($response->getName(), 'PHP Unit Test 3');
+    }
+     */
+
+    // test upload file
+    public function testUploadFile()
+    {
+        // upload file
+        $pet_id = 10001;
+        $response = $this->api->uploadFile($pet_id, 'test meta', __DIR__ . '/../composer.json');
+        // return ApiResponse
+        $this->assertInstanceOf(ApiResponse::class, $response);
+    }
+
+    /*
+     * comment out as we've removed invalid endpoints from the spec, we'll introduce something
+     * similar in the future when we've time to update the petstore server
+     *
+    // test byte array response
+    public function testGetPetByIdWithByteArray()
+    {
+        // initialize the API client
+        $config = new Configuration();
+        $config->setHost('http://petstore.swagger.io/v2');
+        $api_client = new APIClient($config);
+        $pet_api = new Api\PetApi($api_client);
+        // test getPetByIdWithByteArray 
+        $pet_id = 10005;
+        $bytes = $pet_api->petPetIdtestingByteArraytrueGet($pet_id);
+        $json = json_decode($bytes, true);
+
+        $this->assertInternalType("string", $bytes);
+
+        $this->assertSame($json['id'], $pet_id);
+        // not testing name as it's tested by addPetUsingByteArray
+        //$this->assertSame($json['name'], 'PHP Unit Test');
+        $this->assertSame($json['category']['id'], $pet_id);
+        $this->assertSame($json['category']['name'], 'test php category');
+        $this->assertSame($json['tags'][0]['id'], $pet_id);
+        $this->assertSame($json['tags'][0]['name'], 'test php tag');
+    }
+     */
+
+    // test empty object serialization
+    public function testEmptyPetSerialization()
+    {
+        $new_pet = new Model\Pet;
+        // the empty object should be serialised to {}
+        $this->assertSame("{}", "$new_pet");
+    }
+
+    // test inheritance in the model
+    public function testInheritance()
+    {
+        $new_dog = new Model\Dog;
+        // the object should be an instance of the derived class
+        $this->assertInstanceOf('Swagger\Client\Model\Dog', $new_dog);
+        // the object should also be an instance of the parent class
+        $this->assertInstanceOf('Swagger\Client\Model\Animal', $new_dog);
+    }
+
+    // test inheritance constructor is working with data
+    // initialization
+    public function testInheritanceConstructorDataInitialization()
+    {
+        // initialize the object with data in the constructor
+        $data = array(
+            'class_name' => 'Dog',
+            'breed' => 'Great Dane'
+        );
+        $new_dog = new Model\Dog($data);
+
+        // the property on the derived class should be set
+        $this->assertSame('Great Dane', $new_dog->getBreed());
+        // the property on the parent class should be set
+        $this->assertSame('Dog', $new_dog->getClassName());
+    }
+
+    // test if discriminator is initialized automatically
+    public function testDiscriminatorInitialization()
+    {
+        $new_dog = new Model\Dog();
+        $this->assertSame('Dog', $new_dog->getClassName());
+    }
+
+    // test if ArrayAccess interface works
+    public function testArrayStuff()
+    {
+        // create an AnimalFarm which is an object implementing the
+        // ArrayAccess interface
+        $farm = new Model\AnimalFarm();
+
+        // add some animals to the farm to make sure the ArrayAccess
+        // interface works
+        $farm[] = new Model\Dog();
+        $farm[] = new Model\Cat();
+        $farm[] = new Model\Animal();
+
+        // assert we can look up the animals in the farm by array
+        // indices (let's try a random order)
+        $this->assertInstanceOf('Swagger\Client\Model\Cat', $farm[1]);
+        $this->assertInstanceOf('Swagger\Client\Model\Dog', $farm[0]);
+        $this->assertInstanceOf('Swagger\Client\Model\Animal', $farm[2]);
+
+        // let's try to `foreach` the animals in the farm and let's
+        // try to use the objects we loop through
+        foreach ($farm as $animal) {
+            $this->assertContains($animal->getClassName(), array('Dog', 'Cat', 'Animal'));
+            $this->assertInstanceOf('Swagger\Client\Model\Animal', $animal);
+        }
+    }
+
+    // test if default values works
+    public function testDefaultValues()
+    {
+        // add some animals to the farm to make sure the ArrayAccess
+        // interface works
+        $dog = new Model\Dog();
+        $animal = new Model\Animal();
+
+        // assert we can look up the animals in the farm by array
+        // indices (let's try a random order)
+        $this->assertSame('red', $dog->getColor());
+        $this->assertSame('red', $animal->getColor());
+    }
+
+    /**
+     * test invalid argument
+     *
+     * @expectedException \InvalidArgumentException
+     * @expectedExceptionMessage Missing the required parameter $status when calling findPetsByStatus
+     */
+    public function testInvalidArgument()
+    {
+        // the argument is required, and we must specify one or some from 'available', 'pending', 'sold'
+        $this->api->findPetsByStatus([]);
+    }
+
+//    Disabled as currently we don't have any endpoint that would return file
+//    For testing I just replaced url and return type in Api method.
+//    public function testDownloadingLargeFile()
+//    {
+//        $petId = 10005;
+//        $config = new Configuration();
+//        $config->setHost('https://getcomposer.org');
+//        $api = new PetApi(new Client(), $config);
+//        $result = $api->getPetById($petId);
+//        $this->assertInstanceOf(\SplFileObject::class, $result);
+//        var_dump([
+//            'peak mem (MiB)' => memory_get_peak_usage(true)/1024/1024,
+//            'file size (MiB)' => $result->getSize()/1024/1024,
+//            'path' => sys_get_temp_dir() . '/' . $result->getFilename()
+//        ]);
+//    }
+}
diff --git a/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/PetTest.php b/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/PetTest.php
new file mode 100644
index 00000000000..60ce604c522
--- /dev/null
+++ b/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/PetTest.php
@@ -0,0 +1,18 @@
+<?php
+
+namespace Swagger\Client;
+
+use Swagger\Client\Model\Pet;
+
+class PetTest extends \PHPUnit_Framework_TestCase
+{
+    /**
+     * test empty object serialization
+     */
+    public function testEmptyPetSerialization()
+    {
+        $new_pet = new Pet;
+        // the empty object should be serialised to {}
+        $this->assertSame("{}", "$new_pet");
+    }
+}
diff --git a/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/RequestTest.php b/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/RequestTest.php
new file mode 100644
index 00000000000..779ae71ab02
--- /dev/null
+++ b/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/RequestTest.php
@@ -0,0 +1,34 @@
+<?php
+
+namespace Swagger\Client;
+
+use Swagger\Client\Api\FakeApi;
+
+class RequestTest extends \PHPUnit_Framework_TestCase
+{
+
+    /** @var FakeApi */
+    private $api;
+    /** @var  FakeHttpClient */
+    private $fakeClient;
+
+    public function setUp()
+    {
+        $this->fakeClient = new FakeHttpClient();
+        $this->api = new Api\FakeApi($this->fakeClient);
+    }
+
+    public function testFormDataEncodingToJson()
+    {
+        $this->api->testJsonFormData('value', 'value2');
+
+        $request = $this->fakeClient->getLastRequest();
+        $contentType = $request->getHeader('Content-Type');
+        $this->assertEquals(['application/json'], $contentType);
+
+        $requestContent = $request->getBody()->getContents();
+
+        $expected = json_encode(['param' => 'value', 'param2' => 'value2']);
+        $this->assertEquals($expected, $requestContent);
+    }
+}
diff --git a/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/ResponseTypesTest.php b/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/ResponseTypesTest.php
new file mode 100644
index 00000000000..71eda338ba9
--- /dev/null
+++ b/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/ResponseTypesTest.php
@@ -0,0 +1,95 @@
+<?php
+
+namespace Swagger\Client;
+
+use GuzzleHttp\Psr7\Response;
+use Swagger\Client\Api\PetApi;
+use Swagger\Client\Model\Pet;
+
+require_once __DIR__ . '/FakeHttpClient.php';
+
+class ResponseTypesTest extends \PHPUnit_Framework_TestCase
+{
+    /** @var PetApi */
+    private $api;
+    /** @var  FakeHttpClient */
+    private $fakeHttpClient;
+
+    public function setUp()
+    {
+        $this->fakeHttpClient = new FakeHttpClient();
+        $this->api = new PetApi($this->fakeHttpClient);
+    }
+
+    public function testDefined200ReturnType()
+    {
+        $this->fakeHttpClient->setResponse(new Response(200, [], json_encode([])));
+        $result = $this->api->getPetById(123);
+
+        $this->assertInstanceOf(Pet::class, $result);
+    }
+
+    public function testDefault2xxReturnType()
+    {
+        $this->fakeHttpClient->setResponse(new Response(255, [], json_encode([])));
+        $result = $this->api->getPetById(123);
+
+        $this->assertInstanceOf(Pet::class, $result);
+    }
+
+    /**
+     * @expectedException \Swagger\Client\ApiException
+     * @expectedExceptionCode 400
+     */
+    public function testDefinedErrorException()
+    {
+        $statusCode = 400;
+
+        $this->fakeHttpClient->setResponse(new Response($statusCode, [], '{}'));
+        $this->api->getPetById(123);
+    }
+
+//    missing case in spec:
+//    responses:
+//        '400':
+//        description: failure
+//        schema:
+//            $ref: '#/definitions/Error'
+//    public function testDefinedErrorResponseObject()
+//    {
+//        $result = null;
+//        try {
+//            $this->fakeHttpClient->setResponse(new Response(400, [], '{}'));
+//            $this->api->getPetById(123);
+//        } catch (ApiException $e) {
+//            $result = $e->getResponseObject();
+//        }
+//
+//        $this->assertInstanceOf(Error::class, $result);
+//    }
+
+    /**
+     * @expectedException \Swagger\Client\ApiException
+     * @expectedExceptionCode 404
+     */
+    public function testDefaultErrorException()
+    {
+        $statusCode = 404;
+
+        $this->fakeHttpClient->setResponse(new Response($statusCode, [], '{}'));
+        $this->api->getPetById(123);
+    }
+
+    public function testDefaultErrorResponseObject()
+    {
+        $result = null;
+        try {
+            $this->fakeHttpClient->setResponse(new Response(404, [], '{}'));
+            $this->api->getPetById(123);
+        } catch (ApiException $e) {
+            $result = $e->getResponseObject();
+        }
+
+        $this->assertNull($result);
+    }
+}
diff --git a/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/StoreApiTest.php b/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/StoreApiTest.php
new file mode 100644
index 00000000000..3af84b8d851
--- /dev/null
+++ b/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/StoreApiTest.php
@@ -0,0 +1,56 @@
+<?php
+
+namespace Swagger\Client;
+
+use Swagger\Client\Api\PetApi;
+use Swagger\Client\Api\StoreApi;
+use Swagger\Client\Model\Category;
+use Swagger\Client\Model\Pet;
+use Swagger\Client\Model\Tag;
+
+class StoreApiTest extends \PHPUnit_Framework_TestCase
+{
+    /** @var  StoreApi */
+    private $api;
+
+    public function setUp()
+    {
+        $this->api = new StoreApi();
+    }
+
+    /**
+     * Setup before running each test case
+     */
+    public static function setUpBeforeClass()
+    {
+        // add a new pet (id 10005) to ensure the pet object is available for all the tests
+        // new pet
+        $id = 10005;
+        $pet = new Pet();
+        $pet->setId($id);
+        $pet->setName('PHP Unit Test');
+        $pet->setStatus('available');
+        // new tag
+        $tag = new Tag();
+        $tag->setId($id); // use the same id as pet
+        $tag->setName('test php tag');
+        // new category
+        $category = new Category();
+        $category->setId($id); // use the same id as pet
+        $category->setName('test php category');
+
+        $pet->setTags([$tag]);
+        $pet->setCategory($category);
+
+        $api = new PetApi();
+        $api->addPet($pet);
+    }
+
+    public function testGetInventory()
+    {
+        $result = $this->api->getInventory();
+
+        $this->assertInternalType('array', $result);
+        $this->assertInternalType('int', $result['available']);
+    }
+}
diff --git a/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/UserApiTest.php b/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/UserApiTest.php
new file mode 100644
index 00000000000..7d6dfcfc1f4
--- /dev/null
+++ b/samples/openapi3/client/petstore/php/SwaggerClient-php/tests/UserApiTest.php
@@ -0,0 +1,32 @@
+<?php
+
+namespace Swagger\Client;
+
+use Swagger\Client\Api\UserApi;
+
+class UserApiTest extends \PHPUnit_Framework_TestCase
+{
+
+    /** @var UserApi*/
+    private $api;
+
+    public function setUp()
+    {
+        $this->api = new Api\UserApi();
+    }
+
+    // test login use
+    public function testLoginUser()
+    {
+        // initialize the API client
+        // login
+        $response = $this->api->loginUser('xxxxx', 'yyyyyyyy');
+        
+        $this->assertInternalType('string', $response);
+        $this->assertRegExp(
+            '/^logged in user session/',
+            $response,
+            "response string starts with 'logged in user session'"
+        );
+    }
+}