refactor Move for more redundancy

As outlined in #3354, a use `Move` fails if the user is moving from a BookWyrm server to another BookWrym server.
This is because:

1. the original code did not announce changes to alsoKnownAs;
2. the original code always checked the locally saved profile rather than refetching the remote data;

This commit fixes both these problems by forcing `MoveUser` to always perform a "refresh" of the local data from the remote, and by saving the user with broadcast=True when updating alsoKnownAs ids.

bookwyrm/tests/views/preferences/test_move.py

@@ -0,0 +1,114 @@
+""" test move functionality """
+import json
+from unittest.mock import patch
+import pathlib
+from django.contrib.sessions.middleware import SessionMiddleware
+from django.test import TestCase
+from django.test.client import RequestFactory
+import responses
+
+from bookwyrm import forms, models, views
+
+
+@patch("bookwyrm.activitystreams.add_status_task.delay")
+@patch("bookwyrm.suggested_users.rerank_suggestions_task.delay")
+@patch("bookwyrm.activitystreams.populate_stream_task.delay")
+@patch("bookwyrm.suggested_users.rerank_user_task.delay")
+class ViewsHelpers(TestCase):  # pylint: disable=too-many-public-methods
+    """viewing and creating statuses"""
+
+    @classmethod
+    def setUpTestData(self):  # pylint: disable=bad-classmethod-argument
+        """we need basic test data and mocks"""
+
+        with patch("bookwyrm.suggested_users.rerank_suggestions_task.delay"), patch(
+            "bookwyrm.activitystreams.populate_stream_task.delay"
+        ), patch("bookwyrm.lists_stream.populate_lists_task.delay"), patch(
+            "bookwyrm.suggested_users.rerank_user_task.delay"
+        ):
+
+            self.local_user = models.User.objects.create_user(
+                "rat",
+                "rat@rat.com",
+                "ratword",
+                local=True,
+                discoverable=True,
+                localname="rat",
+                remote_id="https://your.domain.here/user/rat",
+            )
+
+        with patch("bookwyrm.models.user.set_remote_server.delay"), patch(
+            "bookwyrm.suggested_users.rerank_user_task.delay"
+        ):
+            self.remote_user = models.User.objects.create_user(
+                "mouse@example.com",
+                "mouse@mouse.com",
+                "mouseword",
+                local=False,
+                remote_id="https://example.com/user/mouse",
+            )
+
+    def setUp(self):
+        """individual test setup"""
+        self.factory = RequestFactory()
+        datafile = pathlib.Path(__file__).parent.joinpath(
+            "../../data/ap_user_move.json"
+        )
+        self.userdata = json.loads(datafile.read_bytes())
+        del self.userdata["icon"]
+
+    @responses.activate
+    @patch("bookwyrm.models.user.set_remote_server.delay")
+    @patch("bookwyrm.suggested_users.remove_user_task.delay")
+    @patch("bookwyrm.models.activitypub_mixin.broadcast_task.apply_async")
+    def test_move_user_view(self, *_):
+        """move user"""
+
+        self.assertEqual(self.remote_user.remote_id, "https://example.com/user/mouse")
+        self.assertIsNone(self.local_user.moved_to)
+        self.assertIsNone(self.remote_user.moved_to)
+        self.assertIsNone(self.local_user.also_known_as.first())
+        self.assertIsNone(self.remote_user.also_known_as.first())
+
+        username = "mouse@example.com"
+        wellknown = {
+            "subject": "acct:mouse@example.com",
+            "links": [
+                {
+                    "rel": "self",
+                    "type": "application/activity+json",
+                    "href": "https://example.com/user/mouse",
+                }
+            ],
+        }
+        responses.add(
+            responses.GET,
+            f"https://example.com/.well-known/webfinger?resource=acct:{username}",
+            json=wellknown,
+            status=200,
+        )
+        responses.add(
+            responses.GET,
+            "https://example.com/user/mouse",
+            json=self.userdata,
+            status=200,
+        )
+
+        view = views.MoveUser.as_view()
+        form = forms.MoveUserForm()
+        form.data["target"] = "mouse@example.com"
+        form.data["password"] = "ratword"
+
+        request = self.factory.post("", form.data)
+        request.user = self.local_user
+        middleware = SessionMiddleware()
+        middleware.process_request(request)
+        request.session.save()
+
+        with patch("bookwyrm.models.activitypub_mixin.broadcast_task.apply_async"):
+            view(request)
+            self.local_user.refresh_from_db()
+
+            self.assertEqual(self.local_user.also_known_as.first(), self.remote_user)
+            self.assertEqual(self.remote_user.also_known_as.first(), self.local_user)
+            self.assertEqual(self.local_user.moved_to, "https://example.com/user/mouse")