api: Add routes subscribeToChannel, unsubscribeFromChannel

Author: chrisbobbe

lib/api/route/channels.dart

@@ -4,6 +4,42 @@ import '../core.dart';
 import '../model/model.dart';
 part 'channels.g.dart';
 
+/// https://zulip.com/api/subscribe
+///
+/// [subscriptions] is a list of channel names.
+/// (This is one of the few remaining areas where the Zulip API hasn't migrated
+/// to using IDs.)
+Future<void> subscribeToChannel(ApiConnection connection, {
+  // TODO(server-future): This should use a stream ID, not stream name.
+  //   (Keep dartdoc up to date.)
+  //   Server issue: https://github.com/zulip/zulip/issues/10744
+  required List<String> subscriptions,
+  List<int>? principals,
+}) {
+  return connection.post('subscribeToChannel', (_) {}, 'users/me/subscriptions', {
+    'subscriptions': subscriptions.map((name) => {'name': name}).toList(),
+    if (principals != null) 'principals': principals,
+  });
+}
+
+/// https://zulip.com/api/unsubscribe
+///
+/// [subscriptions] is a list of channel names.
+/// (This is one of the few remaining areas where the Zulip API hasn't migrated
+/// to using IDs.)
+Future<void> unsubscribeFromChannel(ApiConnection connection, {
+  // TODO(server-future): This should use a stream ID, not stream name.
+  //   (Keep dartdoc up to date.)
+  //   Server issue: https://github.com/zulip/zulip/issues/10744
+  required List<String> subscriptions,
+  List<int>? principals,
+}) {
+  return connection.delete('unsubscribeFromChannel', (_) {}, 'users/me/subscriptions', {
+    'subscriptions': subscriptions,
+    if (principals != null) 'principals': principals,
+  });
+}
+
 /// https://zulip.com/api/get-stream-topics
 Future<GetStreamTopicsResult> getStreamTopics(ApiConnection connection, {
   required int streamId,

test/api/route/channels_test.dart

@@ -1,3 +1,5 @@
+import 'dart:convert';
+
 import 'package:checks/checks.dart';
 import 'package:http/http.dart' as http;
 import 'package:flutter_test/flutter_test.dart';
@@ -8,6 +10,38 @@ import '../../stdlib_checks.dart';
 import '../fake_api.dart';
 
 void main() {
+  test('smoke subscribeToChannel', () {
+    return FakeApiConnection.with_((connection) async {
+      connection.prepare(json: {});
+      await subscribeToChannel(connection,
+        subscriptions: ['foo'],
+        principals: [1]);
+      check(connection.takeRequests()).single.isA<http.Request>()
+        ..method.equals('POST')
+        ..url.path.equals('/api/v1/users/me/subscriptions')
+        ..bodyFields.deepEquals({
+          'subscriptions': jsonEncode([{'name': 'foo'}]),
+          'principals': jsonEncode([1]),
+        });
+    });
+  });
+
+  test('smoke unsubscribeFromChannel', () {
+    return FakeApiConnection.with_((connection) async {
+      connection.prepare(json: {});
+      await unsubscribeFromChannel(connection,
+        subscriptions: ['foo'],
+        principals: [1]);
+      check(connection.takeRequests()).single.isA<http.Request>()
+        ..method.equals('DELETE')
+        ..url.path.equals('/api/v1/users/me/subscriptions')
+        ..bodyFields.deepEquals({
+          'subscriptions': jsonEncode(['foo']),
+          'principals': jsonEncode([1]),
+        });
+    });
+  });
+
   test('smoke updateUserTopic', () {
     return FakeApiConnection.with_((connection) async {
       connection.prepare(json: {});