Remove leading dot and warn users about it

packages/file_selector/file_selector/lib/file_selector.dart

@@ -3,8 +3,9 @@
 // found in the LICENSE file.
 
 import 'dart:async';
-import 'package:flutter/foundation.dart';
+
 import 'package:file_selector_platform_interface/file_selector_platform_interface.dart';
+
 export 'package:file_selector_platform_interface/file_selector_platform_interface.dart'
     show XFile, XTypeGroup;
 
@@ -14,7 +15,6 @@ Future<XFile> openFile({
   String initialDirectory,
   String confirmButtonText,
 }) {
-  acceptedTypeGroups = _verifyTypeGroups(acceptedTypeGroups);
   return FileSelectorPlatform.instance.openFile(
       acceptedTypeGroups: acceptedTypeGroups,
       initialDirectory: initialDirectory,
@@ -27,7 +27,6 @@ Future<List<XFile>> openFiles({
   String initialDirectory,
   String confirmButtonText,
 }) {
-  acceptedTypeGroups = _verifyTypeGroups(acceptedTypeGroups);
   return FileSelectorPlatform.instance.openFiles(
       acceptedTypeGroups: acceptedTypeGroups,
       initialDirectory: initialDirectory,
@@ -41,7 +40,6 @@ Future<String> getSavePath({
   String suggestedName,
   String confirmButtonText,
 }) async {
-  acceptedTypeGroups = _verifyTypeGroups(acceptedTypeGroups);
   return FileSelectorPlatform.instance.getSavePath(
       acceptedTypeGroups: acceptedTypeGroups,
       initialDirectory: initialDirectory,
@@ -57,22 +55,3 @@ Future<String> getDirectoryPath({
   return FileSelectorPlatform.instance.getDirectoryPath(
       initialDirectory: initialDirectory, confirmButtonText: confirmButtonText);
 }
-
-List<XTypeGroup> _verifyTypeGroups(List<XTypeGroup> groups) {
-  if (groups == null) return groups;
-  for (var i = 0; i < groups.length; i++) {
-    if (groups[i] == null || groups[i].extensions == null) continue;
-    for (var j = 0; j < groups[i].extensions.length; j++) {
-      if (groups[i].extensions[j] == null) continue;
-      if (groups[i].extensions[j].startsWith('.')) {
-        if (kDebugMode) {
-          print('acceptedTypeGroups[${i}].extensions[${j}]'
-              ' with value "${groups[i].extensions[j]} is invalid.'
-              ' Please remove the leading dot.');
-        }
-        groups[i].extensions[j] = groups[i].extensions[j].substring(1);
-      }
-    }
-  }
-  return groups;
-}

packages/file_selector/file_selector/test/file_selector_test.dart

@@ -79,24 +79,6 @@ void main() {
       final file = await openFile(acceptedTypeGroups: acceptedTypeGroups);
       expect(file, expectedFile);
     });
-
-    test('works with an extension with leading dot', () async {
-      final correctTypeGroups = [
-        XTypeGroup(label: 'images', extensions: [
-          'jpg',
-          'png',
-        ]),
-      ];
-      final incorrectTypeGroups = [
-        XTypeGroup(label: 'images', extensions: [
-          '.jpg',
-          '.png',
-        ]),
-      ];
-
-      openFile(acceptedTypeGroups: incorrectTypeGroups);
-      verify(mock.openFile(acceptedTypeGroups: incorrectTypeGroups));
-    });
   });
 
   group('openFiles', () {

packages/file_selector/file_selector_platform_interface/lib/src/types/x_type_group/x_type_group.dart

@@ -1,6 +1,7 @@
 // Copyright 2020 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.
+import 'package:flutter/foundation.dart';
 
 /// A set of allowed XTypes
 class XTypeGroup {
@@ -14,7 +15,22 @@ class XTypeGroup {
     this.mimeTypes,
     this.macUTIs,
     this.webWildCards,
-  });
+  }) {
+    _verifyExtensions();
+  }
+
+  void _verifyExtensions() {
+    if (extensions == null) return;
+    for (var i = 0; i < extensions!.length; i++) {
+      if (!extensions![i].startsWith('.')) continue;
+      if (kDebugMode) {
+        print('extensions[${i}] with value "${extensions![i]}" is invalid.'
+            ' We are mutating the extensions list to remove the leading dot.'
+            ' Please fix it.');
+      }
+      extensions![i] = extensions![i].substring(1);
+    }
+  }
 
   /// The 'name' or reference to this group of types
   final String? label;
@@ -41,11 +57,4 @@ class XTypeGroup {
       'webWildCards': webWildCards,
     };
   }
-
-  bool operator ==(o) =>
-      label == o.label &&
-      listEquals(extensions, o.extensions) &&
-      listEquals(mimeTypes, o.mimeTypes) &&
-      listEquals(macUTIs, o.macUTIs) &&
-      listEquals(webWildCards, o.webWildCards);
 }

packages/file_selector/file_selector_platform_interface/test/method_channel_file_selector_test.dart

@@ -29,14 +29,14 @@ void main() {
       test('passes the accepted type groups correctly', () async {
         final group = XTypeGroup(
           label: 'text',
-          extensions: ['.txt'],
+          extensions: ['txt'],
           mimeTypes: ['text/plain'],
           macUTIs: ['public.text'],
         );
 
         final groupTwo = XTypeGroup(
             label: 'image',
-            extensions: ['.jpg'],
+            extensions: ['jpg'],
             mimeTypes: ['image/jpg'],
             macUTIs: ['public.image'],
             webWildCards: ['image/*']);
@@ -90,14 +90,14 @@ void main() {
       test('passes the accepted type groups correctly', () async {
         final group = XTypeGroup(
           label: 'text',
-          extensions: ['.txt'],
+          extensions: ['txt'],
           mimeTypes: ['text/plain'],
           macUTIs: ['public.text'],
         );
 
         final groupTwo = XTypeGroup(
             label: 'image',
-            extensions: ['.jpg'],
+            extensions: ['jpg'],
             mimeTypes: ['image/jpg'],
             macUTIs: ['public.image'],
             webWildCards: ['image/*']);
@@ -152,14 +152,14 @@ void main() {
       test('passes the accepted type groups correctly', () async {
         final group = XTypeGroup(
           label: 'text',
-          extensions: ['.txt'],
+          extensions: ['txt'],
           mimeTypes: ['text/plain'],
           macUTIs: ['public.text'],
         );
 
         final groupTwo = XTypeGroup(
             label: 'image',
-            extensions: ['.jpg'],
+            extensions: ['jpg'],
             mimeTypes: ['image/jpg'],
             macUTIs: ['public.image'],
             webWildCards: ['image/*']);

packages/file_selector/file_selector_platform_interface/test/x_type_group_test.dart

@@ -9,7 +9,7 @@ void main() {
   group('XTypeGroup', () {
     test('toJSON() creates correct map', () {
       final label = 'test group';
-      final extensions = ['.txt', '.jpg'];
+      final extensions = ['txt', 'jpg'];
       final mimeTypes = ['text/plain'];
       final macUTIs = ['public.plain-text'];
       final webWildCards = ['image/*'];
@@ -41,5 +41,12 @@ void main() {
       expect(jsonMap['macUTIs'], null);
       expect(jsonMap['webWildCards'], null);
     });
+
+    test('Validates extensions have not leading dots', () {
+      final extensions = ['.txt', '.jpg'];
+      final group = XTypeGroup(extensions: extensions);
+
+      expect(group.extensions, ['txt', 'jpg']);
+    });
   });
 }