Add static analysis tests that cover all scenarios

Author: veewee

psalm.xml

@@ -9,9 +9,10 @@
     <projectFiles>
         <directory name="src" />
         <directory name="examples" />
+        <directory name="static-analysis" />
         <ignoreFiles>
-            <directory name="vendor" />
             <directory name="tests" />
+            <directory name="vendor" />
         </ignoreFiles>
     </projectFiles>
     <stubs>

static-analysis/Transport/Serializer/serializer-transport.php

@@ -0,0 +1,45 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Phpro\HttpTools\StaticAnalysis\Transport\Serializer;
+
+use Phpro\HttpTools\Request\Request;
+use Phpro\HttpTools\Serializer\SerializerInterface;
+use Phpro\HttpTools\Transport\Serializer\SerializerTransport;
+use Phpro\HttpTools\Transport\TransportInterface;
+
+final class Foo
+{
+}
+
+/**
+ * @param SerializerTransport<Foo, null> $x
+ *
+ * @return null
+ */
+function testEmptySerializer(SerializerTransport $x)
+{
+    return $x(new Request('GET', '/', [], new Foo()));
+}
+
+/**
+ * @param SerializerTransport<Foo, Foo> $x
+ */
+function testTargetSerializer(SerializerTransport $x): Foo
+{
+    return $x(new Request('GET', '/', [], new Foo()));
+}
+
+/**
+ * @param TransportInterface<string, string> $transport
+ */
+function test(SerializerInterface $serializer, TransportInterface $transport): void
+{
+    /** @var SerializerTransport<Foo, null> $serializerTransport */
+    $serializerTransport = new SerializerTransport($serializer, $transport);
+
+    testEmptySerializer($serializerTransport);
+
+    testTargetSerializer($serializerTransport->withOutputType(Foo::class));
+}

tests/Unit/Transport/Serializer/SerializerTransportTest.php

@@ -70,7 +70,7 @@ public function it_can_serialize_request_and_deserialize_response_body_and_trans
     public function it_can_handle_requests_without_request_object(): void
     {
         $valueObject = new SomeValueObject('Hello', 'World');
-        $jsonData = \Safe\json_encode($data = ['x' => 'Hello', 'y' => 'World']);
+        $jsonData = Json\encode($data = ['x' => 'Hello', 'y' => 'World']);
         $request = $this->createToolsRequest('GET', '/', []);
 
         $this->client->on(
@@ -90,7 +90,7 @@ public function it_can_handle_requests_without_request_object(): void
     public function it_can_handle_requests_without_response_type(): void
     {
         $valueObject = new SomeValueObject('Hello', 'World');
-        $jsonData = \Safe\json_encode($data = ['x' => 'Hello', 'y' => 'World']);
+        $jsonData = Json\encode($data = ['x' => 'Hello', 'y' => 'World']);
         $request = $this->createToolsRequest('GET', '/', [], $valueObject);
 
         $this->client->on(