test filesystem abstraction

backend/tests/Fakes/FakeFilesystem.php

@@ -0,0 +1,58 @@
+<?php
+
+namespace Tests\Fakes;
+
+use App\Shared\Files\FileToUpload;
+use App\Shared\Files\Filesystem;
+
+class FakeFilesystem implements Filesystem
+{
+    /**
+     * @var array<int, array{file: FileToUpload, folder: string}>
+     */
+    public array $uploads = [];
+
+    /**
+     * @var string[]
+     */
+    public array $deletedPaths = [];
+
+    /**
+     * @var string[]
+     */
+    public array $readPaths = [];
+
+    /**
+     * @var array<string, string>
+     */
+    private array $filesByPath = [];
+
+    public function upload(FileToUpload $file, string $folder): string
+    {
+        $this->uploads[] = ['file' => $file, 'folder' => $folder];
+
+        return $folder . '/fake-' . $file->getOriginalName();
+    }
+
+    public function url(string $path): string
+    {
+        return 'https://test.local/storage/' . $path;
+    }
+
+    public function delete(string $path): void
+    {
+        $this->deletedPaths[] = $path;
+    }
+
+    public function put(string $path, string $contents): void
+    {
+        $this->filesByPath[$path] = $contents;
+    }
+
+    public function read(string $path): ?string
+    {
+        $this->readPaths[] = $path;
+
+        return $this->filesByPath[$path] ?? null;
+    }
+}