Add tests for MealForm

lib/widgets/nutrition/forms.dart

@@ -51,6 +51,7 @@ class MealForm extends StatelessWidget {
         child: Column(
           children: [
             TextFormField(
+              key: Key('field-time'),
               decoration: InputDecoration(labelText: AppLocalizations.of(context)!.time),
               controller: _timeController,
               onTap: () async {
@@ -71,6 +72,7 @@ class MealForm extends StatelessWidget {
               onFieldSubmitted: (_) {},
             ),
             ElevatedButton(
+              key: Key(SUBMIT_BUTTON_KEY_NAME),
               child: Text(AppLocalizations.of(context)!.save),
               onPressed: () async {
                 if (!_form.currentState!.validate()) {

test/nutritional_meal_form_test.dart

@@ -0,0 +1,117 @@
+/*
+ * This file is part of wger Workout Manager <https://github.com/wger-project>.
+ * Copyright (C) 2020, 2021 wger Team
+ *
+ * wger Workout Manager is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * wger Workout Manager is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+import 'package:flutter/material.dart';
+import 'package:flutter_gen/gen_l10n/app_localizations.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:mockito/mockito.dart';
+import 'package:provider/provider.dart';
+import 'package:wger/helpers/consts.dart';
+import 'package:wger/helpers/json.dart';
+import 'package:wger/models/nutrition/meal.dart';
+import 'package:wger/models/nutrition/nutritional_plan.dart';
+import 'package:wger/providers/nutrition.dart';
+import 'package:wger/screens/nutritional_plan_screen.dart';
+import 'package:wger/widgets/nutrition/forms.dart';
+
+import '../test_data/nutritional_plans.dart';
+import 'nutritional_plan_form_test.mocks.dart';
+
+void main() {
+  var mockNutrition = MockNutrition();
+
+  var plan1 = NutritionalPlan.empty();
+  var meal1 = Meal();
+  var meal2 = Meal();
+
+  when(mockNutrition.editMeal(any)).thenAnswer((_) => Future.value(Meal()));
+  when(mockNutrition.addMeal(any, any)).thenAnswer((_) => Future.value(Meal()));
+
+  setUp(() {
+    plan1 = getNutritionalPlan();
+    meal1 = plan1.meals.first;
+    mockNutrition = MockNutrition();
+  });
+
+  Widget createHomeScreen(Meal meal, {locale = 'en'}) {
+    final key = GlobalKey<NavigatorState>();
+
+    return ChangeNotifierProvider<Nutrition>(
+      create: (context) => mockNutrition,
+      child: MaterialApp(
+        locale: Locale(locale),
+        localizationsDelegates: AppLocalizations.localizationsDelegates,
+        supportedLocales: AppLocalizations.supportedLocales,
+        navigatorKey: key,
+        home: Scaffold(
+          body: MealForm(1, meal),
+        ),
+        routes: {
+          NutritionalPlanScreen.routeName: (ctx) => NutritionalPlanScreen(),
+        },
+      ),
+    );
+  }
+
+  testWidgets('Test the widgets on the meal form', (WidgetTester tester) async {
+    await tester.pumpWidget(createHomeScreen(meal1));
+    await tester.pumpAndSettle();
+
+    expect(find.byType(TextFormField), findsOneWidget);
+    expect(find.byType(ElevatedButton), findsOneWidget);
+    expect(find.byKey(Key(SUBMIT_BUTTON_KEY_NAME)), findsOneWidget);
+  });
+
+  testWidgets('Test editing an existing meal', (WidgetTester tester) async {
+    await tester.pumpWidget(createHomeScreen(meal1));
+    await tester.pumpAndSettle();
+
+    expect(
+      find.text(('17:00')),
+      findsOneWidget,
+      reason: 'Time of existing meal is filled in',
+    );
+    await tester.enterText(find.byKey(Key('field-time')), '12:34');
+    await tester.tap(find.byKey(Key(SUBMIT_BUTTON_KEY_NAME)));
+
+    // Correct method was called
+    verify(mockNutrition.editMeal(any));
+    verifyNever(mockNutrition.addMeal(any, any));
+  });
+
+  testWidgets('Test creating a new nutritional plan', (WidgetTester tester) async {
+    await tester.pumpWidget(createHomeScreen(meal2));
+    await tester.pumpAndSettle();
+
+    expect(
+      find.text(timeToString(TimeOfDay.now())!),
+      findsOneWidget,
+      reason: 'Current time is filled in',
+    );
+
+    await tester.enterText(find.byKey(Key('field-time')), '08:00');
+    await tester.tap(find.byKey(Key(SUBMIT_BUTTON_KEY_NAME)));
+
+    // Correct method was called
+    verifyNever(mockNutrition.editMeal(any));
+    verify(mockNutrition.addMeal(any, any));
+
+    // Detail page
+    // ...
+  });
+}