api: Add route updateUserTopic

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

Author: PIG208

lib/api/route/channels.dart

@@ -1,6 +1,7 @@
 import 'package:json_annotation/json_annotation.dart';
 
 import '../core.dart';
+import '../model/model.dart';
 part 'channels.g.dart';
 
 /// https://zulip.com/api/get-stream-topics
@@ -38,3 +39,33 @@ class GetStreamTopicsEntry {
 
   Map<String, dynamic> toJson() => _$GetStreamTopicsEntryToJson(this);
 }
+
+/// https://zulip.com/api/update-user-topic
+/// https://zulip.com/api/mute-topic (legacy)
+Future<void> updateUserTopic(ApiConnection connection, {
+  required int streamId,
+  required String topic,
+  required UserTopicVisibilityPolicy visibilityPolicy,
+}) {
+  assert(visibilityPolicy != UserTopicVisibilityPolicy.unknown);
+  if (connection.zulipFeatureLevel! < 170) {
+    // TODO(server-7): deprecated in FL 170
+    assert(visibilityPolicy == UserTopicVisibilityPolicy.none
+           || visibilityPolicy == UserTopicVisibilityPolicy.muted);
+    // There can be an error when muting a topic that was already muted
+    // or unmuting one that was already unmuted.  Let it throw because we can't
+    // reliably filter out the error, which doesn't have a specific "code";
+    // and we don't have a useful follow-up other than displaying the error.
+    return connection.post('muteTopic', (_) {}, 'users/me/subscriptions/muted_topics', {
+      'stream_id': streamId,
+      'topic': RawParameter(topic),
+      'op': RawParameter(
+        visibilityPolicy == UserTopicVisibilityPolicy.none ? 'remove' : 'add'),
+    });
+  }
+  return connection.post('updateUserTopic', (_) {}, 'user_topics', {
+    'stream_id': streamId,
+    'topic': RawParameter(topic),
+    'visibility_policy': visibilityPolicy,
+  });
+}

test/api/route/channels_test.dart

@@ -0,0 +1,72 @@
+import 'package:checks/checks.dart';
+import 'package:http/http.dart' as http;
+import 'package:flutter_test/flutter_test.dart';
+import 'package:zulip/api/model/model.dart';
+import 'package:zulip/api/route/channels.dart';
+
+import '../../stdlib_checks.dart';
+import '../fake_api.dart';
+
+void main() {
+  test('smoke updateUserTopic', () {
+    return FakeApiConnection.with_((connection) async {
+      connection.prepare(json: {});
+      await updateUserTopic(connection,
+        streamId: 1, topic: 'topic',
+        visibilityPolicy: UserTopicVisibilityPolicy.followed);
+      check(connection.takeRequests()).single.isA<http.Request>()
+        ..method.equals('POST')
+        ..url.path.equals('/api/v1/user_topics')
+        ..bodyFields.deepEquals({
+          'stream_id': '1',
+          'topic': 'topic',
+          'visibility_policy': '3',
+        });
+    });
+  });
+
+  test('updateUserTopic only accepts valid visibility policy', () {
+    return FakeApiConnection.with_((connection) async {
+      check(() => updateUserTopic(connection,
+        streamId: 1, topic: 'topic',
+        visibilityPolicy: UserTopicVisibilityPolicy.unknown),
+      ).throws<AssertionError>();
+    });
+  });
+
+  group('legacy: use muteTopic when FL < 170', () {
+    test('policy: none -> op: remove', () {
+      return FakeApiConnection.with_(zulipFeatureLevel: 169, (connection) async {
+        connection.prepare(json: {});
+        await updateUserTopic(connection,
+          streamId: 1, topic: 'topic',
+          visibilityPolicy: UserTopicVisibilityPolicy.none);
+        check(connection.takeRequests()).single.isA<http.Request>()
+          ..method.equals('POST')
+          ..url.path.equals('/api/v1/users/me/subscriptions/muted_topics')
+          ..bodyFields.deepEquals({
+            'stream_id': '1',
+            'topic': 'topic',
+            'op': 'remove',
+          });
+      });
+    });
+
+    test('policy: muted -> op: add', () {
+      return FakeApiConnection.with_(zulipFeatureLevel: 169, (connection) async {
+        connection.prepare(json: {});
+        await updateUserTopic(connection,
+          streamId: 1, topic: 'topic',
+          visibilityPolicy: UserTopicVisibilityPolicy.muted);
+        check(connection.takeRequests()).single.isA<http.Request>()
+          ..method.equals('POST')
+          ..url.path.equals('/api/v1/users/me/subscriptions/muted_topics')
+          ..bodyFields.deepEquals({
+            'stream_id': '1',
+            'topic': 'topic',
+            'op': 'add',
+          });
+      });
+    });
+  });
+}