Add WP_In_Memory_Filesystem and use more consistent methods names

src/WordPress/Filesystem/WP_Abstract_Filesystem.php

@@ -40,16 +40,16 @@ abstract public function is_file($path);
 	 * 
 	 * @example
 	 * 
-	 * $fs->start_streaming_file($path);
+	 * $fs->open_file_stream($path);
 	 * while($fs->next_file_chunk()) {
 	 *     $chunk = $fs->get_file_chunk();
 	 *     // process $chunk
 	 * }
-	 * $fs->close_file_reader();
+	 * $fs->close_file_stream();
 	 * 
 	 * @param string $path The path to the file.
 	 */
-	abstract public function start_streaming_file($path);
+	abstract public function open_file_stream($path);
 
 	/**
 	 * Get the next chunk of a file.
@@ -65,6 +65,13 @@ abstract public function next_file_chunk();
 	 */
 	abstract public function get_file_chunk();
 
+    /**
+     * Get the length of the streamed file.
+     * 
+     * @return int|false The length of the file or false if the file is not streamed.
+     */
+    abstract public function get_streamed_file_length();
+
 	/**
 	 * Get the error message of the filesystem.
 	 * 
@@ -75,7 +82,7 @@ abstract public function get_error_message();
 	/**
 	 * Close the file reader.
 	 */
-	abstract public function close_file_reader();
+	abstract public function close_file_stream();
 
 	// @TODO: Support for write methods, perhaps in a separate interface?
 	// abstract public function append_to($path, $data);
@@ -93,8 +100,8 @@ abstract public function close_file_reader();
 	 * @param string $path The path to the file.
 	 * @return string|false The contents of the file or false if the file does not exist.
 	 */
-	public function read_file($path) {
-		$this->start_streaming_file($path);
+	public function get_contents($path) {
+		$this->open_file_stream($path);
 		$body = '';
 		while($this->next_file_chunk()) {
 			$chunk = $this->get_file_chunk();
@@ -103,7 +110,7 @@ public function read_file($path) {
 			}
 			$body .= $chunk;
 		}
-		$this->close_file_reader();
+		$this->close_file_stream();
 		return $body;
 	}
 

src/WordPress/Filesystem/WP_In_Memory_Filesystem.php

@@ -0,0 +1,164 @@
+<?php
+
+namespace WordPress\Filesystem;
+
+/**
+ * Represents an in-memory filesystem.
+ */
+class WP_In_Memory_Filesystem extends WP_Abstract_Filesystem {
+
+	private $files = [];
+	private $last_file_reader = null;
+
+	public function __construct() {
+		$this->files['/'] = [
+			'type' => 'dir',
+			'contents' => []
+		];
+	}
+
+	public function ls($parent = '/') {
+		$parent = rtrim($parent, '/');
+		if (!isset($this->files[$parent]) || $this->files[$parent]['type'] !== 'dir') {
+			return false;
+		}
+		return array_keys($this->files[$parent]['contents']);
+	}
+
+	public function is_dir($path) {
+		return isset($this->files[$path]) && $this->files[$path]['type'] === 'dir';
+	}
+
+	public function is_file($path) {
+		return isset($this->files[$path]) && $this->files[$path]['type'] === 'file';
+	}
+
+	public function exists($path) {
+		return isset($this->files[$path]);
+	}
+
+	private function get_parent_dir($path) {
+		$path = rtrim($path, '/');
+		$parent = dirname($path);
+		if($parent === '.') {
+			return '/';
+		}
+		return $parent;
+	}
+
+	public function open_file_stream($path) {
+		if($this->last_file_reader) {
+			$this->last_file_reader->close();
+		}
+		if (!$this->is_file($path)) {
+			return false;
+		}
+		$this->last_file_reader = \WordPress\ByteReader\WP_String_Reader::create($this->files[$path]['contents']);
+		return true;
+	}
+
+	public function next_file_chunk() {
+		return $this->last_file_reader->next_bytes();
+	}
+
+	public function get_file_chunk() {
+		return $this->last_file_reader->get_bytes();
+	}
+
+	public function get_streamed_file_length() {
+		return $this->last_file_reader->length();
+	}
+
+	public function get_error_message() {
+		return $this->last_file_reader->get_last_error();
+	}
+
+	public function close_file_stream() {
+		if($this->last_file_reader) {
+			$this->last_file_reader->close();
+			$this->last_file_reader = null;
+		}
+	}
+
+	public function rename($old_path, $new_path) {
+		if (!$this->exists($old_path)) {
+			return false;
+		}
+
+		$parent = $this->get_parent_dir($new_path);
+		if (!$this->is_dir($parent)) {
+			return false;
+		}
+
+		$this->files[$new_path] = $this->files[$old_path];
+		unset($this->files[$old_path]);
+		return true;
+	}
+
+	public function mkdir($path) {
+		if ($this->exists($path)) {
+			return false;
+		}
+
+		$parent = $this->get_parent_dir($path);
+		if (!$this->is_dir($parent)) {
+			return false;
+		}
+
+		$this->files[$path] = [
+			'type' => 'dir',
+			'contents' => []
+		];
+		$this->files[$parent]['contents'][basename($path)] = true;
+		return true;
+	}
+
+	public function rm($path) {
+		if (!$this->is_file($path)) {
+			return false;
+		}
+
+		$parent = $this->get_parent_dir($path);
+		unset($this->files[$parent]['contents'][basename($path)]);
+		unset($this->files[$path]);
+		return true;
+	}
+
+	public function rmdir($path, $options = []) {
+		$recursive = $options['recursive'] ?? false;
+		if (!$this->is_dir($path)) {
+			return false;
+		}
+
+		if ($recursive) {
+			$path = rtrim($path, '/');
+			foreach($this->ls($path) as $child) {
+				if($this->is_dir($path . '/' . $child)) {
+					$this->rmdir($path . '/' . $child, $options);
+				} else {
+					$this->rm($path . '/' . $child);
+				}
+			}
+		}
+
+		$parent = $this->get_parent_dir($path);
+		unset($this->files[$parent]['contents'][basename($path)]);
+		unset($this->files[$path]);
+		return true;
+	}
+
+	public function put_contents($path, $data) {
+		$parent = $this->get_parent_dir($path);
+		if (!$this->is_dir($parent)) {
+			return false;
+		}
+
+		$this->files[$path] = [
+			'type' => 'file',
+			'contents' => $data
+		];
+		$this->files[$parent]['contents'][basename($path)] = true;
+		return true;
+	}
+
+}

src/WordPress/Filesystem/WP_Local_Filesystem.php

@@ -56,7 +56,7 @@ public function exists($path) {
 	//        but that could suggest that the reader is a separate object
 	//        and that we can have multiple readers open at the same time.
 	private $last_file_reader = null;
-	public function start_streaming_file($path) {
+	public function open_file_stream($path) {
 		if($this->last_file_reader) {
 			$this->last_file_reader->close();
 		}
@@ -73,11 +73,15 @@ public function get_file_chunk() {
 		return $this->last_file_reader->get_bytes();
 	}
 
+    public function get_streamed_file_length() {
+        return $this->last_file_reader->length();
+    }
+
 	public function get_error_message() {
 		return $this->last_file_reader->get_last_error();
 	}
 
-	public function close_file_reader() {
+	public function close_file_stream() {
 		if($this->last_file_reader) {
 			$this->last_file_reader->close();
 			$this->last_file_reader = null;