feat(nextcloud): Use enum for WebDAV depth

Signed-off-by: jld3103 <jld3103yt@gmail.com>

packages/nextcloud/lib/src/webdav/client.dart

@@ -234,16 +234,15 @@ class WebDavClient {
 
   /// Retrieves the props for the resource at [path].
   ///
-  /// Optionally populates the given [prop]s on the returned files.
-  /// [depth] can be '0', '1' or 'infinity'.
+  /// Optionally populates the given [prop]s on the returned resources.
+  /// [depth] can be used to limit scope of the returned resources.
   /// See http://www.webdav.org/specs/rfc2518.html#METHOD_PROPFIND for more information.
   Future<WebDavMultistatus> propfind(
     final String path, {
     final WebDavPropWithoutValues? prop,
-    final String? depth,
-  }) async {
-    assert(depth == null || ['0', '1', 'infinity'].contains(depth), 'Depth has to be 0, 1 or infinity');
-    return _parseResponse(
+    final WebDavDepth? depth,
+  }) async =>
+      _parseResponse(
         await _send(
           'PROPFIND',
           _constructPath(path),
@@ -258,16 +257,15 @@ class WebDavClient {
           ),
           headers: {
             if (depth != null) ...{
-            'Depth': depth,
+              'Depth': depth.value,
             },
           },
         ),
       );
-  }
 
   /// Runs the filter-files report with the [filterRules] on the resource at [path].
   ///
-  /// Optionally populates the [prop]s on the returned files.
+  /// Optionally populates the [prop]s on the returned resources.
   /// See https://github.com/owncloud/docs/issues/359 for more information.
   Future<WebDavMultistatus> report(
     final String path,
@@ -378,3 +376,26 @@ class WebDavOptions {
   /// DAV search and locating capabilities as advertised by the server in the 'dasl' header.
   Set<String> searchCapabilities;
 }
+
+/// Depth used for [WebDavClient.propfind].
+///
+/// See http://www.webdav.org/specs/rfc2518.html#HEADER_Depth for more information.
+enum WebDavDepth {
+  /// Returns props of the resource.
+  zero('0'),
+
+  /// Returns props of the resource and its immediate children.
+  ///
+  /// Only works on collections and returns the same as [WebDavDepth.zero] for other resources.
+  one('1'),
+
+  /// Returns props of the resource and all its progeny.
+  ///
+  /// Only works on collections and returns the same as [WebDavDepth.zero] for other resources.
+  infinity('infinity');
+
+  const WebDavDepth(this.value);
+
+  // ignore: public_member_api_docs
+  final String value;
+}

packages/nextcloud/test/webdav_test.dart

@@ -47,7 +47,7 @@ void main() {
     test('List directory recursively', () async {
       final responses = (await client.webdav.propfind(
         '/',
-        depth: 'infinity',
+        depth: WebDavDepth.infinity,
       ))
           .responses;
       expect(responses, hasLength(48));
@@ -149,7 +149,7 @@ void main() {
           davresourcetype: true,
           ocsize: true,
         ),
-        depth: '0',
+        depth: WebDavDepth.zero,
       ))
           .toWebDavFiles()
           .single;