test: add tests for ChannelPreviewTheme

packages/stream_chat_flutter/test/src/theme/channel_preview_theme_test.dart

@@ -0,0 +1,108 @@
+import 'package:flutter/material.dart' hide TextTheme;
+import 'package:flutter_test/flutter_test.dart';
+import 'package:stream_chat_flutter/stream_chat_flutter.dart';
+
+void main() {
+  test('ChannelPreviewThemeData copyWith, ==, hashCode basics', () {
+    expect(const ChannelPreviewThemeData(),
+        const ChannelPreviewThemeData().copyWith());
+    expect(const ChannelPreviewThemeData().hashCode,
+        const ChannelPreviewThemeData().copyWith().hashCode);
+  });
+
+  group('ChannelPreviewThemeData lerps', () {
+    test(
+        '''Light ChannelPreviewThemeData lerps completely to dark ChannelPreviewThemeData''',
+        () {
+      expect(
+          const ChannelPreviewThemeData().lerp(
+              _channelPreviewThemeControl, _channelPreviewThemeControlDark, 1),
+          _channelPreviewThemeControlDark);
+    });
+
+    test(
+        '''Light ChannelPreviewThemeData lerps halfway to dark ChannelPreviewThemeData''',
+        () {
+      expect(
+          const ChannelPreviewThemeData().lerp(_channelPreviewThemeControl,
+              _channelPreviewThemeControlDark, 0.5),
+          _channelPreviewThemeControlMidLerp);
+    });
+
+    test(
+        '''Dark ChannelPreviewThemeData lerps completely to light ChannelPreviewThemeData''',
+        () {
+      expect(
+          const ChannelPreviewThemeData().lerp(
+              _channelPreviewThemeControlDark, _channelPreviewThemeControl, 1),
+          _channelPreviewThemeControl);
+    });
+  });
+
+  test('Merging dark and light themes results in a dark theme', () {
+    expect(_channelPreviewThemeControl.merge(_channelPreviewThemeControlDark),
+        _channelPreviewThemeControlDark);
+  });
+}
+
+final _channelPreviewThemeControl = ChannelPreviewThemeData(
+  unreadCounterColor: ColorTheme.light().accentError,
+  avatarTheme: AvatarThemeData(
+    borderRadius: BorderRadius.circular(20),
+    constraints: const BoxConstraints.tightFor(
+      height: 40,
+      width: 40,
+    ),
+  ),
+  titleStyle: TextTheme.light().bodyBold,
+  subtitleStyle: TextTheme.light().footnote.copyWith(
+        color: const Color(0xff7A7A7A),
+      ),
+  lastMessageAtStyle: TextTheme.light().footnote.copyWith(
+        color: ColorTheme.light().textHighEmphasis.withOpacity(.5),
+      ),
+  indicatorIconSize: 16,
+);
+
+final _channelPreviewThemeControlMidLerp = ChannelPreviewThemeData(
+  unreadCounterColor: const Color(0xffff3842),
+  avatarTheme: AvatarThemeData(
+    borderRadius: BorderRadius.circular(20),
+    constraints: const BoxConstraints.tightFor(
+      height: 40,
+      width: 40,
+    ),
+  ),
+  titleStyle: const TextStyle(
+    color: Color(0xff000000),
+    fontSize: 14,
+    fontWeight: FontWeight.bold,
+  ),
+  subtitleStyle: const TextStyle(
+    color: Color(0xff7a7a7a),
+    fontSize: 12,
+  ),
+  lastMessageAtStyle: TextTheme.light().footnote.copyWith(
+        color: Color(0x80000000).withOpacity(.5),
+      ),
+  indicatorIconSize: 16,
+);
+
+final _channelPreviewThemeControlDark = ChannelPreviewThemeData(
+  unreadCounterColor: ColorTheme.dark().accentError,
+  avatarTheme: AvatarThemeData(
+    borderRadius: BorderRadius.circular(20),
+    constraints: const BoxConstraints.tightFor(
+      height: 40,
+      width: 40,
+    ),
+  ),
+  titleStyle: TextTheme.dark().bodyBold,
+  subtitleStyle: TextTheme.dark().footnote.copyWith(
+        color: const Color(0xff7A7A7A),
+      ),
+  lastMessageAtStyle: TextTheme.dark().footnote.copyWith(
+        color: ColorTheme.dark().textHighEmphasis.withOpacity(.5),
+      ),
+  indicatorIconSize: 16,
+);