test(localizations): write a few tests for FlutterQuillLocalizationsWidget

lib/src/l10n/extensions/localizations.dart

@@ -4,18 +4,23 @@ import '../generated/quill_localizations.dart' as generated;
 
 typedef FlutterQuillLocalizations = generated.FlutterQuillLocalizations;
 
+class MissingFlutterQuillLocalizationException extends UnimplementedError {
+  MissingFlutterQuillLocalizationException();
+  @override
+  String? get message =>
+      'FlutterQuillLocalizations instance is required and could not found. '
+      'Ensure that you are wrapping the current widget with '
+      'FlutterQuillLocalizationsWidget or add '
+      'FlutterQuillLocalizations.delegate to the localizationsDelegates '
+      'in your App widget (e.,g WidgetsApp, MaterialApp). If you believe this is a bug, consider reporting it.';
+}
+
 extension LocalizationsExt on BuildContext {
   /// Require the [FlutterQuillLocalizations] instance
   ///
   /// `loc` is short for `localizations`
   FlutterQuillLocalizations get loc {
     return FlutterQuillLocalizations.of(this) ??
-        (throw UnimplementedError(
-          "The instance of FlutterQuillLocalizations.of(context) is null and it's"
-          ' required, please make sure you wrapping the current widget with '
-          'FlutterQuillLocalizationsWidget or add '
-          'FlutterQuillLocalizations.delegate to the localizationsDelegates '
-          'in your App widget, please consider reporting this as a bug',
-        ));
+        (throw MissingFlutterQuillLocalizationException());
   }
 }

test/widgets/editor_test.dart

@@ -3,6 +3,7 @@ import 'dart:convert' show jsonDecode;
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter_quill/flutter_quill.dart';
+import 'package:flutter_quill/translations.dart';
 import 'package:flutter_quill_test/flutter_quill_test.dart';
 import 'package:flutter_test/flutter_test.dart';
 
@@ -137,5 +138,82 @@ void main() {
       await tester.tap(find.byIcon(Icons.copy));
       expect(didCopy, isTrue);
     });
+
+    testWidgets(
+      'make sure QuillEditorOpenSearchAction does not throw an exception',
+      (tester) async {
+        final editorFocusNode = FocusNode();
+        await tester.pumpWidget(
+          MaterialApp(
+            home: QuillEditor.basic(
+              configurations: QuillEditorConfigurations(controller: controller),
+              focusNode: editorFocusNode,
+            ),
+          ),
+        );
+        // Required, otherwise the action shortcuts won't be invoked.
+        editorFocusNode.requestFocus();
+
+        await tester.sendKeyDownEvent(LogicalKeyboardKey.control);
+        await tester.sendKeyEvent(LogicalKeyboardKey.keyF);
+        await tester.sendKeyUpEvent(LogicalKeyboardKey.control);
+
+        await tester.pump();
+
+        final exception = tester.takeException();
+        expect(
+          exception,
+          isNot(
+            isInstanceOf<MissingFlutterQuillLocalizationException>(),
+          ),
+        );
+
+        expect(exception, isNull);
+      },
+    );
+
+    testWidgets(
+      'should throw FlutterQuillLocalizationsWidget if the delegate not provided',
+      (tester) async {
+        await tester.pumpWidget(
+          MaterialApp(
+            home: Builder(
+              builder: (context) => Text(context.loc.font),
+            ),
+          ),
+        );
+
+        final exception = tester.takeException();
+
+        expect(exception, isNotNull);
+        expect(
+          exception,
+          isA<MissingFlutterQuillLocalizationException>(),
+        );
+      },
+    );
+
+    testWidgets(
+      'should not throw FlutterQuillLocalizationsWidget if the delegate is provided',
+      (tester) async {
+        await tester.pumpWidget(
+          MaterialApp(
+            home: FlutterQuillLocalizationsWidget(
+              child: Builder(
+                builder: (context) => Text(context.loc.font),
+              ),
+            ),
+          ),
+        );
+
+        final exception = tester.takeException();
+
+        expect(exception, isNull);
+        expect(
+          exception,
+          isNot(isA<MissingFlutterQuillLocalizationException>()),
+        );
+      },
+    );
   });
 }