api: Add unregister{Apns,Fcm}Token; link to new docs for register-token fns

It's no longer true that these endpoints are undocumented, so, link
to them.

Author: chrisbobbe

lib/api/route/notifications.dart

@@ -1,11 +1,7 @@
 
 import '../core.dart';
 
-// This endpoint is undocumented.  Compare zulip-mobile:
-//   https://github.com/zulip/zulip-mobile/blob/86d94fa89/src/api/notifications/savePushToken.js
-// and see the server implementation:
-//   https://github.com/zulip/zulip/blob/34ceafadd/zproject/urls.py#L383
-//   https://github.com/zulip/zulip/blob/34ceafadd/zerver/views/push_notifications.py#L47
+/// https://zulip.com/api/add-fcm-token
 Future<void> registerFcmToken(ApiConnection connection, {
   required String token,
 }) {
@@ -14,11 +10,16 @@ Future<void> registerFcmToken(ApiConnection connection, {
   });
 }
 
-// This endpoint is undocumented.  Compare zulip-mobile:
-//   https://github.com/zulip/zulip-mobile/blob/86d94fa89/src/api/notifications/savePushToken.js
-// and see the server implementation:
-//   https://github.com/zulip/zulip/blob/34ceafadd/zproject/urls.py#L378-L381
-//   https://github.com/zulip/zulip/blob/34ceafadd/zerver/views/push_notifications.py#L34
+/// https://zulip.com/api/remove-fcm-token
+Future<void> unregisterFcmToken(ApiConnection connection, {
+  required String token,
+}) {
+  return connection.delete('unregisterFcmToken', (_) {}, 'users/me/android_gcm_reg_id', {
+    'token': RawParameter(token),
+  });
+}
+
+/// https://zulip.com/api/add-apns-token
 Future<void> registerApnsToken(ApiConnection connection, {
   required String token,
   String? appid,
@@ -28,3 +29,12 @@ Future<void> registerApnsToken(ApiConnection connection, {
     if (appid != null) 'appid': RawParameter(appid),
   });
 }
+
+/// https://zulip.com/api/remove-apns-token
+Future<void> unregisterApnsToken(ApiConnection connection, {
+  required String token,
+}) {
+  return connection.delete('unregisterApnsToken', (_) {}, 'users/me/apns_device_token', {
+    'token': RawParameter(token),
+  });
+}

test/api/route/notifications_test.dart

@@ -28,6 +28,27 @@ void main() {
     });
   });
 
+  group('unregisterFcmToken', () {
+    Future<void> checkUnregisterFcmToken(FakeApiConnection connection, {
+      required String token,
+    }) async {
+      connection.prepare(json: {});
+      await unregisterFcmToken(connection, token: token);
+      check(connection.lastRequest).isA<http.Request>()
+        ..method.equals('DELETE')
+        ..url.path.equals('/api/v1/users/me/android_gcm_reg_id')
+        ..bodyFields.deepEquals({
+          'token': token,
+        });
+    }
+
+    test('smoke', () {
+      return FakeApiConnection.with_((connection) async {
+        await checkUnregisterFcmToken(connection, token: 'asdf');
+      });
+    });
+  });
+
   group('registerApnsToken', () {
     Future<void> checkRegisterApnsToken(FakeApiConnection connection, {
       required String token,
@@ -56,4 +77,25 @@ void main() {
       });
     });
   });
+
+  group('unregisterApnsToken', () {
+    Future<void> checkUnregisterApnsToken(FakeApiConnection connection, {
+      required String token,
+    }) async {
+      connection.prepare(json: {});
+      await unregisterApnsToken(connection, token: token);
+      check(connection.lastRequest).isA<http.Request>()
+        ..method.equals('DELETE')
+        ..url.path.equals('/api/v1/users/me/apns_device_token')
+        ..bodyFields.deepEquals({
+          'token': token,
+        });
+    }
+
+    test('smoke', () {
+      return FakeApiConnection.with_((connection) async {
+        await checkUnregisterApnsToken(connection, token: 'asdf');
+      });
+    });
+  });
 }