[path_provider] Fixed support for querying the root external storage directory (#6036)

Author: gaaclarke

packages/path_provider/path_provider_android/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 2.0.16
+
+* Fixes bug with `getExternalStoragePaths(null)`.
+
 ## 2.0.15
 
 * Switches the medium from MethodChannels to Pigeon.

packages/path_provider/path_provider_android/android/src/main/java/io/flutter/plugins/pathprovider/Messages.java

@@ -1,7 +1,7 @@
 // Copyright 2013 The Flutter Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
-// Autogenerated from Pigeon (v3.1.5), do not edit directly.
+// Autogenerated from Pigeon (v3.2.0), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 
 package io.flutter.plugins.pathprovider;
@@ -23,16 +23,17 @@
 public class Messages {
 
   public enum StorageDirectory {
-    music(0),
-    podcasts(1),
-    ringtones(2),
-    alarms(3),
-    notifications(4),
-    pictures(5),
-    movies(6),
-    downloads(7),
-    dcim(8),
-    documents(9);
+    root(0),
+    music(1),
+    podcasts(2),
+    ringtones(3),
+    alarms(4),
+    notifications(5),
+    pictures(6),
+    movies(7),
+    downloads(8),
+    dcim(9),
+    documents(10);
 
     private int index;
 

packages/path_provider/path_provider_android/android/src/main/java/io/flutter/plugins/pathprovider/PathProviderPlugin.java

@@ -125,6 +125,8 @@ private List<String> getPathProviderExternalCacheDirectories() {
 
   private String getStorageDirectoryString(@NonNull Messages.StorageDirectory directory) {
     switch (directory) {
+      case root:
+        return null;
       case music:
         return "music";
       case podcasts:

packages/path_provider/path_provider_android/example/integration_test/path_provider_test.dart

@@ -68,6 +68,7 @@ void main() {
       final List<String>? directories =
           await provider.getExternalStoragePaths(type: type);
       expect(directories, isNotNull);
+      expect(directories, isNotEmpty);
       for (final String result in directories!) {
         _verifySampleFile(result, '$type');
       }

packages/path_provider/path_provider_android/lib/messages.g.dart

@@ -1,7 +1,7 @@
 // Copyright 2013 The Flutter Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
-// Autogenerated from Pigeon (v3.1.5), do not edit directly.
+// Autogenerated from Pigeon (v3.2.0), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name
 // @dart = 2.12
@@ -12,6 +12,7 @@ import 'package:flutter/foundation.dart' show WriteBuffer, ReadBuffer;
 import 'package:flutter/services.dart';
 
 enum StorageDirectory {
+  root,
   music,
   podcasts,
   ringtones,

packages/path_provider/path_provider_android/lib/path_provider_android.dart

@@ -5,8 +5,11 @@
 import 'package:path_provider_platform_interface/path_provider_platform_interface.dart';
 import 'messages.g.dart' as messages;
 
-messages.StorageDirectory _convertStorageDirectory(StorageDirectory directory) {
+messages.StorageDirectory _convertStorageDirectory(
+    StorageDirectory? directory) {
   switch (directory) {
+    case null:
+      return messages.StorageDirectory.root;
     case StorageDirectory.music:
       return messages.StorageDirectory.music;
     case StorageDirectory.podcasts:
@@ -73,10 +76,8 @@ class PathProviderAndroid extends PathProviderPlatform {
   Future<List<String>?> getExternalStoragePaths({
     StorageDirectory? type,
   }) async {
-    return type == null
-        ? <String>[]
-        : (await _api.getExternalStoragePaths(_convertStorageDirectory(type)))
-            .cast<String>();
+    return (await _api.getExternalStoragePaths(_convertStorageDirectory(type)))
+        .cast<String>();
   }
 
   @override

packages/path_provider/path_provider_android/pigeons/messages.dart

@@ -14,6 +14,7 @@ import 'package:pigeon/pigeon.dart';
   copyrightHeader: 'pigeons/copyright.txt',
 ))
 enum StorageDirectory {
+  root,
   music,
   podcasts,
   ringtones,

packages/path_provider/path_provider_android/pubspec.yaml

@@ -2,7 +2,7 @@ name: path_provider_android
 description: Android implementation of the path_provider plugin.
 repository: https://github.com/flutter/plugins/tree/main/packages/path_provider/path_provider_android
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+path_provider%22
-version: 2.0.15
+version: 2.0.16
 
 environment:
   sdk: ">=2.14.0 <3.0.0"

packages/path_provider/path_provider_android/test/path_provider_android_test.dart

@@ -89,12 +89,6 @@ void main() {
       });
     } // end of for-loop
 
-    test('getExternalStoragePaths with null android succeeds', () async {
-      final List<String>? result =
-          await pathProvider.getExternalStoragePaths(type: null);
-      expect(result!.length, 0);
-    });
-
     test('getDownloadsPath fails', () async {
       try {
         await pathProvider.getDownloadsPath();