add adapter pattern

adapterpattern/AdapterTest.php

@@ -0,0 +1,26 @@
+<?php 
+
+require_once __DIR__ . '/../vendor/autoload.php';
+
+use PHPUnit\Framework\TestCase;
+
+class AdapterTest extends TestCase
+{
+    public function test_filesystem_adapter() : void
+    {   
+        $client = new AdapterPattern\App\Client();
+
+        $local_filesystem = new AdapterPattern\App\LocalFilesystem();
+        $this->assertEquals($client->readFile($local_filesystem), 'opening local file');
+
+        // this wont work since dropbox doesnt adhere to the same interface
+        /*
+        $dropbox_filesystem = new AdapterPattern\App\Dropbox();
+        $this->assertEquals($client->readFile($dropbox_filesystem), 'opening dropbox file');
+        */
+
+        // so we use an adapter which implements the interface we want to adhere to
+        $dropbox_filesystem = new AdapterPattern\App\Dropbox();
+        $this->assertEquals($client->readFile(new AdapterPattern\App\FilesystemAdapter($dropbox_filesystem)), 'opening dropbox file');
+    }
+}

adapterpattern/app/Client.php

@@ -0,0 +1,11 @@
+<?php 
+
+namespace AdapterPattern\App;
+
+class Client
+{
+    public function readFile(FilesystemInterface $filesystem)
+    {
+        return $filesystem->open();
+    }
+}

adapterpattern/app/CloudFilesystemInterface.php

@@ -0,0 +1,8 @@
+<?php
+
+namespace AdapterPattern\App;
+
+interface CloudFilesystemInterface 
+{
+    public function openFile();
+}

adapterpattern/app/Dropbox.php

@@ -0,0 +1,11 @@
+<?php 
+
+namespace AdapterPattern\App;
+
+class Dropbox implements CloudFilesystemInterface
+{
+    public function openFile()
+    {
+        return 'opening dropbox file';
+    }
+}

adapterpattern/app/FilesystemAdapter.php

@@ -0,0 +1,18 @@
+<?php 
+
+namespace AdapterPattern\App;
+
+class FilesystemAdapter implements FilesystemInterface 
+{
+
+    public function __construct(private CloudFilesystemInterface $filesystem)
+    {
+
+    }
+
+    public function open()
+    {
+        return $this->filesystem->openFile();
+    }
+
+}

adapterpattern/app/FilesystemInterface.php

@@ -0,0 +1,9 @@
+<?php 
+
+namespace AdapterPattern\App; 
+
+interface FilesystemInterface 
+{
+    public function open();
+
+}

adapterpattern/app/LocalFilesystem.php

@@ -0,0 +1,13 @@
+<?php 
+
+namespace AdapterPattern\App;
+
+class LocalFilesystem implements FilesystemInterface
+{
+
+    public function open()
+    {
+        return 'opening local file';
+    }
+
+}

composer.json

@@ -9,7 +9,8 @@
     "autoload": {
         "psr-4": {
             "DecoratorPattern\\App\\": "decoratorpattern/app/",
-            "FacadePattern\\App\\": "facadepattern/app/"
+            "FacadePattern\\App\\": "facadepattern/app/",
+            "AdapterPattern\\App\\": "adapterpattern/app/"
         }
     },
     "require-dev": {