Added missing attributedTo to Articles

refs https://linear.app/tryghost/issue/AP-427

This was missing and made it difficult for implementations to Like or Announce
our articles, because they needed a reference to the Create activity to get the
authors inbox

features/create-article-from-post.feature

@@ -5,3 +5,4 @@ Feature: Deliver Create(Article) activities when a post.published webhook is rec
     When it is sent to the webhook endpoint
     Then the request is accepted
     Then a "Create(Article)" activity is in the Outbox
+    And the found "Create(Article)" has property "object.attributedTo"

features/step_definitions/stepdefs.js

@@ -470,9 +470,23 @@ Then('a {string} activity is in the Outbox', async function (string) {
     const found = outbox.orderedItems.find((item) => {
         return item.type === activity && item.object?.type === object
     });
+    if (!this.found) {
+        this.found = {};
+    }
+    this.found[string] = found;
     assert.ok(found);
 });
 
+Then('the found {string} has property {string}', function (name, prop) {
+    const found = this.found[name];
+
+    const property = prop.split('.').reduce(function (thing, key) {
+        return thing?.[key];
+    }, found);
+
+    assert.ok(property);
+});
+
 Then('{string} is in our Inbox', async function (activityName) {
     const response = await fetch('http://activitypub-testing:8083/.ghost/activitypub/inbox/index', {
         headers: {

src/handlers.ts

@@ -53,7 +53,7 @@ const PostSchema = z.object({
 
 type Post = z.infer<typeof PostSchema>
 
-async function postToArticle(ctx: RequestContext<ContextData>, post: Post) {
+async function postToArticle(ctx: RequestContext<ContextData>, post: Post, author: Actor | null) {
     if (!post) {
         return {
             article: null,
@@ -66,6 +66,7 @@ async function postToArticle(ctx: RequestContext<ContextData>, post: Post) {
     });
     const article = new Article({
         id: ctx.getObjectUri(Article, { id: post.uuid }),
+        attribution: author,
         name: post.title,
         content: post.html,
         image: toURL(post.feature_image),
@@ -366,12 +367,13 @@ export async function postPublishedWebhook(
         db: ctx.get('db'),
         globaldb: ctx.get('globaldb'),
     });
+    const actor = await apCtx.getActor(ACTOR_DEFAULT_HANDLE);
     const { article, preview } = await postToArticle(
         apCtx,
         data.post.current,
+        actor
     );
     if (article) {
-        const actor = await apCtx.getActor(ACTOR_DEFAULT_HANDLE);
         const create = new Create({
             actor,
             object: article,