submessage test [nfc]: Extract pollWidgetData.

The goal is to make the relevant context of the test data local to the
tests, and keep the example data as boring as possible.

We also combine the smoke test into the test for invalid widget types,
contrasting it with the failing cases.

Signed-off-by: Zixuan James Li <[email protected]>

Author: PIG208

lib/api/model/submessage.dart

@@ -65,7 +65,9 @@ enum SubmessageType {
 ///  * Zero or more submessages with content [PollEventSubmessage] if the
 ///    message is a poll (i.e. if the first submessage was a [PollWidgetData]),
 ///    and similarly for other types of widgets.
-sealed class SubmessageData {}
+sealed class SubmessageData {
+  Object? toJson();
+}
 
 /// The data encoded in a submessage to make the message a Zulip widget.
 ///
@@ -87,6 +89,7 @@ sealed class WidgetData extends SubmessageData {
     };
   }
 
+  @override
   Object? toJson();
 }
 
@@ -188,6 +191,7 @@ sealed class PollEventSubmessage extends SubmessageData {
     }
   }
 
+  @override
   Map<String, Object?> toJson();
 }
 

test/api/model/submessage_test.dart

@@ -3,6 +3,7 @@ import 'package:test/scaffolding.dart';
 import 'package:zulip/api/model/submessage.dart';
 
 import '../../example_data.dart' as eg;
+import '../../stdlib_checks.dart';
 import 'submessage_checks.dart';
 
 void main() {
@@ -27,23 +28,25 @@ void main() {
     });
   });
 
-  test('smoke WidgetData',  () {
-    check(WidgetData.fromJson(eg.pollWidgetDataFavoriteLetter)).isA<PollWidgetData>()
+  test('invalid widget_type -> UnsupportedWidgetData/throw', () {
+    final pollWidgetData = deepToJson(eg.pollWidgetData(
+      question: 'example question',
+      options: ['A', 'B', 'C'],
+    )) as Map<String, Object?>;
+
+    check(WidgetData.fromJson(pollWidgetData)).isA<PollWidgetData>()
       ..widgetType.equals(WidgetType.poll)
       ..extraData.which((x) => x
-          ..question.equals('favorite letter')
+          ..question.equals('example question')
           ..options.deepEquals(['A', 'B', 'C'])
         );
-  });
-
-  test('invalid widget_type -> UnsupportedWidgetData/throw', () {
     check(WidgetData.fromJson({
-      ...eg.pollWidgetDataFavoriteLetter,
+      ...pollWidgetData,
       'widget_type': 'unknown_foo',
     })).isA<UnsupportedWidgetData>();
 
     check(() => WidgetData.fromJson({
-      ...eg.pollWidgetDataFavoriteLetter,
+      ...pollWidgetData,
       'widget_type': 123,
     })).throws<TypeError>();
   });

test/example_data.dart

@@ -3,6 +3,7 @@ import 'dart:math';
 import 'package:zulip/api/model/events.dart';
 import 'package:zulip/api/model/initial_snapshot.dart';
 import 'package:zulip/api/model/model.dart';
+import 'package:zulip/api/model/submessage.dart';
 import 'package:zulip/api/route/realm.dart';
 import 'package:zulip/api/route/channels.dart';
 import 'package:zulip/model/narrow.dart';
@@ -405,13 +406,13 @@ DmMessage dmMessage({
   }) as Map<String, dynamic>);
 }
 
-const pollWidgetDataFavoriteLetter = {
-  'widget_type': 'poll',
-  'extra_data': {
-    'question': 'favorite letter',
-    'options': ['A', 'B', 'C'],
-  }
-};
+PollWidgetData pollWidgetData({
+  required String question,
+  required List<String> options,
+}) {
+  return PollWidgetData(
+    extraData: PollWidgetExtraData(question: question, options: options));
+}
 
 ////////////////////////////////////////////////////////////////
 // Aggregate data structures.