Merge branch 'undo-follow' into 'master'

Support ActivityPub unfollow

See merge request jaywink/federation!146

federation/entities/activitypub/entities.py

@@ -37,6 +37,9 @@ class ActivitypubFollow(ActivitypubObjectMixin, Follow):
         """
         Post receive hook - send back follow ack.
         """
+        if not self.following:
+            return
+
         from federation.utils.activitypub import retrieve_and_parse_profile  # Circulars
         try:
             from federation.utils.django import get_function_from_config
@@ -78,13 +81,27 @@ class ActivitypubFollow(ActivitypubObjectMixin, Follow):
             logger.exception("ActivitypubFollow.post_receive - Failed to send Accept back")
 
     def to_as2(self) -> Dict:
-        as2 = {
-            "@context": CONTEXTS_DEFAULT,
-            "id": self.activity_id,
-            "type": self._type,
-            "actor": self.actor_id,
-            "object": self.target_id,
-        }
+        if self.following:
+            as2 = {
+                "@context": CONTEXTS_DEFAULT,
+                "id": self.activity_id,
+                "type": self._type,
+                "actor": self.actor_id,
+                "object": self.target_id,
+            }
+        else:
+            as2 = {
+                "@context": CONTEXTS_DEFAULT,
+                "id": self.activity_id,
+                "type": ActivityType.UNDO.value,
+                "actor": self.actor_id,
+                "object": {
+                    "id": f"{self.actor_id}#follow-{uuid.uuid4()}",
+                    "type": self._type,
+                    "actor": self.actor_id,
+                    "object": self.target_id,
+                },
+            }
         return as2
 
 

federation/entities/activitypub/mappers.py

@@ -14,10 +14,11 @@ logger = logging.getLogger("federation")
 MAPPINGS = {
     "Accept": ActivitypubAccept,
     "Article": ActivitypubPost,
-    "Follow": ActivitypubFollow,
+    "Follow": ActivitypubFollow,  # Technically not correct, but for now we support only following profiles
     "Note": ActivitypubPost,
     "Page": ActivitypubPost,
     "Person": ActivitypubProfile,
+    "Undo": ActivitypubFollow,  # Technically not correct, but for now we support only undoing a follow of a profile
 }
 
 
@@ -158,8 +159,10 @@ def transform_attribute(key: str, value: Union[str, Dict, int], transformed: Dic
         transformed["name"] = value
     elif key == "object":
         if isinstance(value, dict):
-            if cls in (ActivitypubAccept, ActivitypubFollow):
+            if cls == ActivitypubAccept:
                 transformed["target_id"] = value.get("id")
+            elif cls == ActivitypubFollow:
+                transformed["target_id"] = value.get("object")
             else:
                 transform_attributes(value, cls, transformed, is_object=True)
         else:
@@ -173,6 +176,9 @@ def transform_attribute(key: str, value: Union[str, Dict, int], transformed: Dic
     elif key in ("to", "cc"):
         if isinstance(value, list) and NAMESPACE_PUBLIC in value:
             transformed["public"] = True
+    elif key == "type":
+        if value == "Undo":
+            transformed["following"] = False
     elif key == "url":
         transformed["url"] = value
 

federation/tests/entities/activitypub/test_entities.py

@@ -26,6 +26,32 @@ class TestEntitiesConvertToAS2:
             },
         }
 
+    def test_follow_to_as2(self, activitypubfollow):
+        result = activitypubfollow.to_as2()
+        assert result == {
+            "@context": CONTEXTS_DEFAULT,
+            "id": "https://localhost/follow",
+            "type": "Follow",
+            "actor": "https://localhost/profile",
+            "object": "https://example.com/profile"
+        }
+
+    def test_follow_to_as2__undo(self, activitypubundofollow):
+        result = activitypubundofollow.to_as2()
+        result["object"]["id"] = "https://localhost/follow"  # Real object will have a random UUID postfix here
+        assert result == {
+            "@context": CONTEXTS_DEFAULT,
+            "id": "https://localhost/undo",
+            "type": "Undo",
+            "actor": "https://localhost/profile",
+            "object": {
+                "id": "https://localhost/follow",
+                "type": "Follow",
+                "actor": "https://localhost/profile",
+                "object": "https://example.com/profile",
+            }
+        }
+
     def test_post_to_as2(self, activitypubpost):
         result = activitypubpost.to_as2()
         assert result == {

federation/tests/entities/activitypub/test_mappers.py

@@ -5,7 +5,8 @@ import pytest
 from federation.entities.activitypub.entities import ActivitypubFollow, ActivitypubAccept, ActivitypubProfile
 from federation.entities.activitypub.mappers import message_to_objects, get_outbound_entity
 from federation.entities.base import Accept, Follow, Profile
-from federation.tests.fixtures.payloads import ACTIVITYPUB_FOLLOW, ACTIVITYPUB_PROFILE, ACTIVITYPUB_PROFILE_INVALID
+from federation.tests.fixtures.payloads import (
+    ACTIVITYPUB_FOLLOW, ACTIVITYPUB_PROFILE, ACTIVITYPUB_PROFILE_INVALID, ACTIVITYPUB_UNDO_FOLLOW)
 
 
 class TestActivitypubEntityMappersReceive:
@@ -23,6 +24,15 @@ class TestActivitypubEntityMappersReceive:
         assert entity.target_id == "https://example.org/actor"
         assert entity.following is True
 
+    def test_message_to_objects__unfollow(self):
+        entities = message_to_objects(ACTIVITYPUB_UNDO_FOLLOW, "https://example.com/actor")
+        assert len(entities) == 1
+        entity = entities[0]
+        assert isinstance(entity, ActivitypubFollow)
+        assert entity.actor_id == "https://example.com/actor"
+        assert entity.target_id == "https://example.org/actor"
+        assert entity.following is False
+
     @pytest.mark.skip
     def test_message_to_objects_mentions_are_extracted(self):
         entities = message_to_objects(

federation/tests/fixtures/entities.py

@@ -58,6 +58,16 @@ def activitypubprofile():
     )
 
 
+@pytest.fixture
+def activitypubundofollow():
+    return ActivitypubFollow(
+        activity_id="https://localhost/undo",
+        actor_id="https://localhost/profile",
+        target_id="https://example.com/profile",
+        following=False,
+    )
+
+
 @pytest.fixture
 def profile():
     return Profile(

federation/tests/fixtures/payloads/activitypub.py

@@ -7,12 +7,6 @@ ACTIVITYPUB_FOLLOW = {
   "type": "Follow",
   "actor": "https://example.com/actor",
   "object": "https://example.org/actor",
-  "signature": {
-    "type": "RsaSignature2017",
-    "creator": "https://example.com/actor#main-key",
-    "created": "2018-10-11T15:59:32Z",
-    "signatureValue": "foobar"
-  }
 }
 
 ACTIVITYPUB_PROFILE = {
@@ -99,3 +93,19 @@ ACTIVITYPUB_PROFILE_INVALID = {
     "publicKeyPem": "-----BEGIN PUBLIC KEY-----\nMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAwVbaT5wvaZobfIB044ai\nhJg/XooEn2jSTnTY1K4mPmhdqYUmszpdXKp64OwA+f3SBuIUIkLAYUSB9Fu19zh+\nzOsoGI5gvA32DHY1vaqdKnT9gt3jKS5AdQ3bl0t9f4pPkO2I5YtQOWV1FvBcwPXG\nB0dIqj0fTqNK37FmyybrRD6uhjySddklN9gNsULTqYVDa0QSXVswTIW2jQudnNlp\nnEf3SfjlK9J8eKPF3hFK3PNXBTTZ4NydBSL3cVBinU0cFg8lUJOK8RI4qaetrVoQ\neKd7gCTSQ7RZh8kmkYmdlweb+ZtORT6Y5ZsotR8jwhAOFAqCt36B5+LX2UIw68Pk\nOwIDAQAB\n-----END PUBLIC KEY-----\n"
   },
 }
+
+ACTIVITYPUB_UNDO_FOLLOW = {
+  "@context": [
+    "https://www.w3.org/ns/activitystreams",
+    "https://w3id.org/security/v1",
+  ],
+  "id": "https://example.com/undo",
+  "type": "Undo",
+  "actor": "https://example.com/actor",
+  "object": {
+    "id": "https://example.com/follow",
+    "type": "Follow",
+    "actor": "https://example.com/actor",
+    "object": "https://example.org/actor",
+  },
+}