ReelShort/test/recommend/recommend_top_nav_motion_test.dart

// Author: fruit.com.cn
// 职责：验证首页三标签文字和下划线随页面进度连续变化。
import 'package:flutter/material.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:fruitshorts/core/theme/app_colors.dart';
import 'package:fruitshorts/l10n/app_localizations.dart';
import 'package:fruitshorts/pages/recommend/recommend_types.dart';
import 'package:fruitshorts/pages/recommend/widgets/recommend_top_nav.dart';

const _pagePosition = 0.35;
const _duration = Duration(milliseconds: 90);
const _epsilon = 0.0001;

Widget _host({
  double? position,
  RecommendInnerTab tab = RecommendInnerTab.feed,
}) {
  return MaterialApp(
    localizationsDelegates: AppLocalizations.localizationsDelegates,
    supportedLocales: AppLocalizations.supportedLocales,
    home: Scaffold(
      body: RecommendTopNav(
        selected: tab,
        pagePosition: position,
        onSelected: (_) {},
        onSearch: () {},
      ),
    ),
  );
}

double _scale(WidgetTester tester, String tab) => tester
    .widget<Transform>(
      find.descendant(
        of: find.byKey(Key('recommend-tab-$tab')),
        matching: find.byType(Transform),
      ),
    )
    .transform
    .entry(0, 0);

Color _underline(WidgetTester tester, String tab) {
  final line = tester.widget<Container>(
    find.byKey(Key('recommend-tab-$tab-underline')),
  );
  return (line.decoration! as BoxDecoration).color!;
}

void main() {
  testWidgets(
    'should_brighten_only_inactive_home_tabs_when_selection_changes',
    (tester) async {
      const inactive = Color(0xFFC7C7CC);
      const codes = ['recommend', 'playlist', 'all'];
      for (final tab in RecommendInnerTab.values) {
        await tester.pumpWidget(
          _host(position: tab.index.toDouble(), tab: tab),
        );
        for (final (index, code) in codes.indexed) {
          final text = tester.widget<Text>(
            find.descendant(
              of: find.byKey(Key('recommend-tab-$code')),
              matching: find.byType(Text),
            ),
          );
          expect(
            text.style?.color,
            index == tab.index ? AppColors.textPrimary : inactive,
          );
        }
      }
      await tester.pumpWidget(_host(position: _pagePosition));
      final text = tester.widget<Text>(
        find.descendant(
          of: find.byKey(const Key('recommend-tab-playlist')),
          matching: find.byType(Text),
        ),
      );
      expect(
        text.style?.color,
        Color.lerp(inactive, AppColors.textPrimary, _pagePosition),
      );
      expect(AppColors.textTabInactive, const Color(0xFFB0B0B0));
    },
  );

  testWidgets('should_keep_regular_enlarged_labels_for_every_selection', (
    tester,
  ) async {
    for (final tab in RecommendInnerTab.values) {
      await tester.pumpWidget(_host(position: tab.index.toDouble(), tab: tab));
      for (final code in ['recommend', 'playlist', 'all']) {
        final text = tester.widget<Text>(
          find.descendant(
            of: find.byKey(Key('recommend-tab-$code')),
            matching: find.byType(Text),
          ),
        );
        expect(text.style?.fontSize, 18);
        expect(text.style?.fontWeight, FontWeight.w400);
      }
      expect(tester.takeException(), isNull);
    }
  });

  testWidgets('should_follow_page_position_without_delayed_label_animation', (
    tester,
  ) async {
    await tester.pumpWidget(_host(position: 0));
    final first = tester.getRect(
      find.byKey(const Key('recommend-tab-recommend')),
    );
    final second = tester.getRect(
      find.byKey(const Key('recommend-tab-playlist')),
    );
    await tester.pumpWidget(
      _host(position: _pagePosition, tab: RecommendInnerTab.playlists),
    );
    expect(_scale(tester, 'recommend'), closeTo(0.965, _epsilon));
    expect(_scale(tester, 'playlist'), closeTo(0.935, _epsilon));
    expect(_underline(tester, 'recommend').a, closeTo(0.65, _epsilon));
    expect(_underline(tester, 'playlist').a, closeTo(0.35, _epsilon));
    expect(_underline(tester, 'all').a, 0);
    expect(
      tester.getRect(find.byKey(const Key('recommend-tab-recommend'))),
      first,
    );
    expect(
      tester.getRect(find.byKey(const Key('recommend-tab-playlist'))),
      second,
    );
    await tester.pumpWidget(_host(position: 0));
    expect(_scale(tester, 'recommend'), 1);
    expect(_underline(tester, 'recommend'), AppColors.brandRed);
  });

  testWidgets('should_fade_both_underlines_when_used_without_page_position', (
    tester,
  ) async {
    await tester.pumpWidget(_host());
    await tester.pumpWidget(_host(tab: RecommendInnerTab.playlists));
    await tester.pump(_duration);
    expect(_underline(tester, 'recommend').a, inExclusiveRange(0.0, 1.0));
    expect(_underline(tester, 'playlist').a, inExclusiveRange(0.0, 1.0));
  });
}