Remove leading dot and warn users about it

Author: tugorez

packages/file_selector/file_selector/lib/file_selector.dart

@@ -14,7 +14,7 @@ Future<XFile> openFile({
   String initialDirectory,
   String confirmButtonText,
 }) {
-  acceptedTypeGroups = _verifyTypeGroups(acceptedTypeGroups);
+  _verifyTypeGroups(acceptedTypeGroups);
   return FileSelectorPlatform.instance.openFile(
       acceptedTypeGroups: acceptedTypeGroups,
       initialDirectory: initialDirectory,
@@ -27,7 +27,7 @@ Future<List<XFile>> openFiles({
   String initialDirectory,
   String confirmButtonText,
 }) {
-  acceptedTypeGroups = _verifyTypeGroups(acceptedTypeGroups);
+  _verifyTypeGroups(acceptedTypeGroups);
   return FileSelectorPlatform.instance.openFiles(
       acceptedTypeGroups: acceptedTypeGroups,
       initialDirectory: initialDirectory,
@@ -41,7 +41,7 @@ Future<String> getSavePath({
   String suggestedName,
   String confirmButtonText,
 }) async {
-  acceptedTypeGroups = _verifyTypeGroups(acceptedTypeGroups);
+  _verifyTypeGroups(acceptedTypeGroups);
   return FileSelectorPlatform.instance.getSavePath(
       acceptedTypeGroups: acceptedTypeGroups,
       initialDirectory: initialDirectory,
@@ -58,21 +58,24 @@ Future<String> getDirectoryPath({
       initialDirectory: initialDirectory, confirmButtonText: confirmButtonText);
 }
 
-List<XTypeGroup> _verifyTypeGroups(List<XTypeGroup> groups) {
-  if (groups == null) return groups;
+void _verifyTypeGroups(List<XTypeGroup> groups) {
+  if (groups == null) return;
   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 "${groups[i].extensions[j]} is invalid.'
-              ' Please remove the leading dot.');
-        }
-        groups[i].extensions[j] = groups[i].extensions[j].substring(1);
-      }
+    _verifyExtensions(groups[i], i);
+  }
+}
+
+void _verifyExtensions(XTypeGroup group, int groupIndex) {
+  if (group == null || group.extensions == null) return;
+  for (var extIndex = 0; extIndex < group.extensions.length; extIndex++) {
+    if (group.extensions[extIndex] == null) continue;
+    if (!group.extensions[extIndex].startsWith('.')) continue;
+    if (kDebugMode) {
+      print('acceptedTypeGroups[${groupIndex}].extensions[${extIndex}]'
+          ' with value "${group.extensions[extIndex]} is invalid.'
+          ' We are removing the leading dot and therefore mutating acceptedTypeGroups.'
+          ' Please fix it.');
     }
+    group.extensions[extIndex] = group.extensions[extIndex].substring(1);
   }
-  return groups;
 }

packages/file_selector/file_selector/test/file_selector_test.dart

@@ -81,21 +81,18 @@ void main() {
     });
 
     test('works with an extension with leading dot', () async {
-      final correctTypeGroups = [
-        XTypeGroup(label: 'images', extensions: [
-          'jpg',
-          'png',
-        ]),
-      ];
+      // We consider this correct because at least one extension has a leading dot.
       final incorrectTypeGroups = [
         XTypeGroup(label: 'images', extensions: [
           '.jpg',
           '.png',
         ]),
       ];
 
+      //ignore: unawaited_futures
       openFile(acceptedTypeGroups: incorrectTypeGroups);
       verify(mock.openFile(acceptedTypeGroups: incorrectTypeGroups));
+      expect(incorrectTypeGroups[0].extensions, ['jpg', 'png']);
     });
   });
 
@@ -149,6 +146,21 @@ void main() {
       final files = await openFiles(acceptedTypeGroups: acceptedTypeGroups);
       expect(files, expectedFiles);
     });
+
+    test('works with an extension with leading dot', () async {
+      // We consider this correct because at least one extension has a leading dot.
+      final incorrectTypeGroups = [
+        XTypeGroup(label: 'images', extensions: [
+          '.jpg',
+          '.png',
+        ]),
+      ];
+
+      // ignore: unawaited_futures
+      openFiles(acceptedTypeGroups: incorrectTypeGroups);
+      verify(mock.openFiles(acceptedTypeGroups: incorrectTypeGroups));
+      expect(incorrectTypeGroups[0].extensions, ['jpg', 'png']);
+    });
   });
 
   group('getSavePath', () {
@@ -212,6 +224,21 @@ void main() {
       final savePath = await getSavePath(suggestedName: suggestedName);
       expect(savePath, expectedSavePath);
     });
+
+    test('works with an extension with leading dot', () async {
+      // We consider this correct because at least one extension has a leading dot.
+      final incorrectTypeGroups = [
+        XTypeGroup(label: 'images', extensions: [
+          '.jpg',
+          '.png',
+        ]),
+      ];
+
+      // ignore: unawaited_futures
+      getSavePath(acceptedTypeGroups: incorrectTypeGroups);
+      verify(mock.getSavePath(acceptedTypeGroups: incorrectTypeGroups));
+      expect(incorrectTypeGroups[0].extensions, ['jpg', 'png']);
+    });
   });
 
   group('getDirectoryPath', () {

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

@@ -41,11 +41,4 @@ 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);
 }