Merge pull request #681 from dahlia/former-type

Preserve deleted entity types in tombstones

Author: dahlia

CHANGES.md

@@ -34,6 +34,14 @@ To be released.
 
 ### @fedify/vocab
 
+ -  Added `Tombstone.formerType` plus generated entity type helpers for deleted
+    vocabulary objects.  Applications can now construct tombstones with Fedify
+    entity classes such as `Person`, and `@fedify/vocab` now exports
+    `$EntityType`, `isEntityType()`, and `getEntityTypeById()` for working with
+    those references.  Unknown remote `formerType` values are ignored with a
+    warning instead of making the whole tombstone fail to parse.
+    [[#645], [#681]]
+
  -  Added [FEP-044f] vocabulary support for Mastodon-style quote posts.
     [[#452], [#679]]
 
@@ -56,7 +64,18 @@ To be released.
 [FEP-0837]: https://w3id.org/fep/0837
 [#452]: https://github.com/fedify-dev/fedify/issues/452
 [#578]: https://github.com/fedify-dev/fedify/issues/578
+[#645]: https://github.com/fedify-dev/fedify/issues/645
 [#679]: https://github.com/fedify-dev/fedify/pull/679
+[#681]: https://github.com/fedify-dev/fedify/pull/681
+
+### @fedify/vocab-tools
+
+ -  Added the `fedify:vocabEntityType` pseudo-scalar to the vocabulary
+    generator.  Vocabulary properties can now accept generated Fedify entity
+    constructors instead of arbitrary IRIs when the schema wants a reference to
+    a known vocabulary type.  Generated code now also emits the supporting
+    `$EntityType`, `isEntityType()`, and `getEntityTypeById()` helpers for
+    working with those references.  [[#645], [#681]]
 
 ### @fedify/cli
 

docs/manual/actor.md

@@ -60,22 +60,25 @@ instead of `null`:
 ~~~~ typescript twoslash
 // @noErrors: 2345
 import { type Federation } from "@fedify/fedify";
-import { Tombstone } from "@fedify/vocab";
+import { Person, Tombstone } from "@fedify/vocab";
 const federation = null as unknown as Federation<void>;
 const deletedAt = Temporal.Instant.from("2024-01-15T00:00:00Z");
 // ---cut-before---
 federation.setActorDispatcher("/users/{identifier}", async (ctx, identifier) => {
   if (identifier !== "alice") return null;
   return new Tombstone({
     id: ctx.getActorUri(identifier),
+    formerType: Person,
     deleted: deletedAt,
   });
 });
 ~~~~
 
 When an actor dispatcher returns a `Tombstone`, Fedify responds from the actor
 endpoint with `410 Gone` and the serialized tombstone body.  WebFinger for the
-same account also responds with `410 Gone`.
+same account also responds with `410 Gone`.  If you know the deleted actor's
+former Fedify entity class, set `formerType` so the tombstone preserves the
+original ActivityStreams type.
 
 Use `null` only when the identifier is not handled at all and the request
 should fall through to the next middleware or `onNotFound` handler.

docs/manual/context.md

@@ -230,7 +230,10 @@ const actor = await ctx.getActor(identifier, {
   tombstone: "passthrough",
 });
 if (actor instanceof Tombstone) {
-  console.log(`${identifier} was deleted at ${actor.deleted}`);
+  console.log(
+    `${identifier} was deleted at ${actor.deleted} ` +
+      `(former type: ${actor.formerType?.name ?? "unknown"})`,
+  );
 }
 ~~~~
 

packages/fedify/src/federation/handler.test.ts

@@ -89,6 +89,7 @@ test("handleActor()", async () => {
     if (identifier !== "gone") return null;
     return new Tombstone({
       id: ctx.getActorUri(identifier),
+      formerType: Person,
       deleted: deletedAt,
     });
   };
@@ -346,6 +347,7 @@ test("handleActor()", async () => {
     ],
     id: "https://example.com/users/gone",
     type: "Tombstone",
+    formerType: "as:Person",
     deleted: "2024-01-15T00:00:00Z",
   });
   assertEquals(onNotFoundCalled, null);