send out poll votes as separate create activities given that no other AP servers support multiple objects in a single activity (#3582)

internal/processing/workers/federate.go

@@ -217,18 +217,23 @@ func (f *federate) CreatePollVote(ctx context.Context, poll *gtsmodel.Poll, vote
 		return err
 	}
 
-	// Convert vote to AS Create with vote choices as Objects.
-	create, err := f.converter.PollVoteToASCreate(ctx, vote)
+	// Convert vote to AS Creates with vote choices as Objects.
+	creates, err := f.converter.PollVoteToASCreates(ctx, vote)
 	if err != nil {
 		return gtserror.Newf("error converting to notes: %w", err)
 	}
 
-	// Send the Create via the Actor's outbox.
-	if _, err := f.FederatingActor().Send(ctx, outboxIRI, create); err != nil {
-		return gtserror.Newf("error sending Create activity via outbox %s: %w", outboxIRI, err)
+	var errs gtserror.MultiError
+
+	// Send each create activity.
+	actor := f.FederatingActor()
+	for _, create := range creates {
+		if _, err := actor.Send(ctx, outboxIRI, create); err != nil {
+			errs.Appendf("error sending Create activity via outbox %s: %w", outboxIRI, err)
+		}
 	}
 
-	return nil
+	return errs.Combine()
 }
 
 func (f *federate) DeleteStatus(ctx context.Context, status *gtsmodel.Status) error {

internal/typeutils/internaltoas.go

@@ -1701,10 +1701,14 @@ func (c *Converter) ReportToASFlag(ctx context.Context, r *gtsmodel.Report) (voc
 // PollVoteToASCreate converts a vote on a poll into a Create
 // activity, suitable for federation, with each choice in the
 // vote appended as a Note to the Create's Object field.
-func (c *Converter) PollVoteToASCreate(
+//
+// TODO: as soon as other AP server implementations support
+// the use of multiple objects in a single create, update this
+// to return just the one create event again.
+func (c *Converter) PollVoteToASCreates(
 	ctx context.Context,
 	vote *gtsmodel.PollVote,
-) (vocab.ActivityStreamsCreate, error) {
+) ([]vocab.ActivityStreamsCreate, error) {
 	if len(vote.Choices) == 0 {
 		panic("no vote.Choices")
 	}
@@ -1743,22 +1747,25 @@ func (c *Converter) PollVoteToASCreate(
 		return nil, gtserror.Newf("invalid account uri: %w", err)
 	}
 
-	// Allocate Create activity and address 'To' poll author.
-	create := streams.NewActivityStreamsCreate()
-	ap.AppendTo(create, pollAuthorIRI)
+	// Parse each choice to a Note and add it to the list of Creates.
+	creates := make([]vocab.ActivityStreamsCreate, len(vote.Choices))
+	for i, choice := range vote.Choices {
 
-	// Create ID formatted as: {$voterIRI}/activity#vote/{$statusIRI}.
-	id := author.URI + "/activity#vote/" + poll.Status.URI
-	ap.MustSet(ap.SetJSONLDIdStr, ap.WithJSONLDId(create), id)
+		// Allocate Create activity and address 'To' poll author.
+		create := streams.NewActivityStreamsCreate()
+		ap.AppendTo(create, pollAuthorIRI)
 
-	// Set Create actor appropriately.
-	ap.AppendActorIRIs(create, authorIRI)
+		// Create ID formatted as: {$voterIRI}/activity#vote{$index}/{$statusIRI}.
+		createID := fmt.Sprintf("%s/activity#vote%d/%s", author.URI, i, poll.Status.URI)
+		ap.MustSet(ap.SetJSONLDIdStr, ap.WithJSONLDId(create), createID)
 
-	// Set publish time for activity.
-	ap.SetPublished(create, vote.CreatedAt)
+		// Set Create actor appropriately.
+		ap.AppendActorIRIs(create, authorIRI)
 
-	// Parse each choice to a Note and add it to the Create.
-	for _, choice := range vote.Choices {
+		// Set publish time for activity.
+		ap.SetPublished(create, vote.CreatedAt)
+
+		// Allocate new note to hold the vote.
 		note := streams.NewActivityStreamsNote()
 
 		// For AP IRI generate from author URI + poll ID + vote choice.
@@ -1775,11 +1782,14 @@ func (c *Converter) PollVoteToASCreate(
 		ap.AppendInReplyTo(note, statusIRI)
 		ap.AppendTo(note, pollAuthorIRI)
 
-		// Append this note as Create Object.
+		// Append this note to the Create Object.
 		appendStatusableToActivity(create, note, false)
+
+		// Set create in slice.
+		creates[i] = create
 	}
 
-	return create, nil
+	return creates, nil
 }
 
 // populateValuesForProp appends the given PolicyValues

internal/typeutils/internaltoas_test.go

@@ -1104,43 +1104,55 @@ func (suite *InternalToASTestSuite) TestPinnedStatusesToASOneItem() {
 func (suite *InternalToASTestSuite) TestPollVoteToASCreate() {
 	vote := suite.testPollVotes["remote_account_1_status_2_poll_vote_local_account_1"]
 
-	create, err := suite.typeconverter.PollVoteToASCreate(context.Background(), vote)
-	if err != nil {
-		suite.FailNow(err.Error())
-	}
+	creates, err := suite.typeconverter.PollVoteToASCreates(context.Background(), vote)
+	suite.NoError(err)
+	suite.Len(creates, 2)
 
-	createI, err := ap.Serialize(create)
+	createI0, err := ap.Serialize(creates[0])
 	suite.NoError(err)
 
-	bytes, err := json.MarshalIndent(createI, "", "  ")
+	createI1, err := ap.Serialize(creates[1])
+	suite.NoError(err)
+
+	bytes0, err := json.MarshalIndent(createI0, "", "  ")
+	suite.NoError(err)
+
+	bytes1, err := json.MarshalIndent(createI1, "", "  ")
 	suite.NoError(err)
 
 	suite.Equal(`{
   "@context": "https://www.w3.org/ns/activitystreams",
   "actor": "http://localhost:8080/users/the_mighty_zork",
-  "id": "http://localhost:8080/users/the_mighty_zork/activity#vote/http://fossbros-anonymous.io/users/foss_satan/statuses/01HEN2QRFA8H3C6QPN7RD4KSR6",
-  "object": [
-    {
-      "attributedTo": "http://localhost:8080/users/the_mighty_zork",
-      "id": "http://localhost:8080/users/the_mighty_zork#01HEN2R65468ZG657C4ZPHJ4EX/votes/1",
-      "inReplyTo": "http://fossbros-anonymous.io/users/foss_satan/statuses/01HEN2QRFA8H3C6QPN7RD4KSR6",
-      "name": "tissues",
-      "to": "http://fossbros-anonymous.io/users/foss_satan",
-      "type": "Note"
-    },
-    {
-      "attributedTo": "http://localhost:8080/users/the_mighty_zork",
-      "id": "http://localhost:8080/users/the_mighty_zork#01HEN2R65468ZG657C4ZPHJ4EX/votes/2",
-      "inReplyTo": "http://fossbros-anonymous.io/users/foss_satan/statuses/01HEN2QRFA8H3C6QPN7RD4KSR6",
-      "name": "financial times",
-      "to": "http://fossbros-anonymous.io/users/foss_satan",
-      "type": "Note"
-    }
-  ],
+  "id": "http://localhost:8080/users/the_mighty_zork/activity#vote0/http://fossbros-anonymous.io/users/foss_satan/statuses/01HEN2QRFA8H3C6QPN7RD4KSR6",
+  "object": {
+    "attributedTo": "http://localhost:8080/users/the_mighty_zork",
+    "id": "http://localhost:8080/users/the_mighty_zork#01HEN2R65468ZG657C4ZPHJ4EX/votes/1",
+    "inReplyTo": "http://fossbros-anonymous.io/users/foss_satan/statuses/01HEN2QRFA8H3C6QPN7RD4KSR6",
+    "name": "tissues",
+    "to": "http://fossbros-anonymous.io/users/foss_satan",
+    "type": "Note"
+  },
   "published": "2021-09-11T11:45:37+02:00",
   "to": "http://fossbros-anonymous.io/users/foss_satan",
   "type": "Create"
-}`, string(bytes))
+}`, string(bytes0))
+
+	suite.Equal(`{
+  "@context": "https://www.w3.org/ns/activitystreams",
+  "actor": "http://localhost:8080/users/the_mighty_zork",
+  "id": "http://localhost:8080/users/the_mighty_zork/activity#vote1/http://fossbros-anonymous.io/users/foss_satan/statuses/01HEN2QRFA8H3C6QPN7RD4KSR6",
+  "object": {
+    "attributedTo": "http://localhost:8080/users/the_mighty_zork",
+    "id": "http://localhost:8080/users/the_mighty_zork#01HEN2R65468ZG657C4ZPHJ4EX/votes/2",
+    "inReplyTo": "http://fossbros-anonymous.io/users/foss_satan/statuses/01HEN2QRFA8H3C6QPN7RD4KSR6",
+    "name": "financial times",
+    "to": "http://fossbros-anonymous.io/users/foss_satan",
+    "type": "Note"
+  },
+  "published": "2021-09-11T11:45:37+02:00",
+  "to": "http://fossbros-anonymous.io/users/foss_satan",
+  "type": "Create"
+}`, string(bytes1))
 }
 
 func (suite *InternalToASTestSuite) TestInteractionReqToASAcceptAnnounce() {