feat(lemmyv1): surface read_comments_at on PostView (#43)

Author: aeharding

src/providers/lemmyv1/compat.ts

@@ -156,6 +156,7 @@ export function toPostView(v: LemmyV1.PostView): types.PostView {
     my_vote: toVote(v.post_actions),
     notifications: v.post_actions?.notifications ?? "replies_and_mentions",
     read: !!v.post_actions?.read_at,
+    read_comments_at: nullToUndef(v.post_actions?.read_comments_at),
     saved: !!v.post_actions?.saved_at,
     subscribed: toFollowState(v.community_actions?.follow_state),
     unread_comments: toUnreadComments(v.post, v.post_actions),

src/schemas/PostView.ts

@@ -21,6 +21,12 @@ export const PostView = z.object({
   notifications: PostNotificationsMode,
   post: Post,
   read: z.boolean(),
+  /**
+   * When the current user last read the comments on this post (ISO 8601).
+   * Comments published after this can be treated as unread. Only provided by
+   * providers that track it (Lemmy v1); `undefined` otherwise.
+   */
+  read_comments_at: z.optional(z.string()),
   saved: z.boolean(),
   subscribed: SubscribedType,
   tags: z.array(PostTag),

test/lemmyv1-compat.test.ts

@@ -107,6 +107,32 @@ describe("v1 compat - my_vote derivation", () => {
     } as any);
     expect(v.my_vote).toBeUndefined();
   });
+
+  it("PostView: surfaces read_comments_at from post_actions", () => {
+    const v = toPostView({
+      ...basePostView(),
+      post_actions: {
+        read_comments_amount: 1,
+        read_comments_at: NOW,
+        // eslint-disable-next-line @typescript-eslint/no-explicit-any
+      } as any,
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    } as any);
+    expect(v.read_comments_at).toBe(NOW);
+  });
+
+  it("PostView: read_comments_at null/absent → undefined", () => {
+    const nulled = toPostView({
+      ...basePostView(),
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
+      post_actions: { read_comments_at: null as any },
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    } as any);
+    expect(nulled.read_comments_at).toBeUndefined();
+
+    const absent = toPostView(basePostView() as never);
+    expect(absent.read_comments_at).toBeUndefined();
+  });
 });
 
 describe("v1 compat - toSupportedNotificationView normalizes null id fields", () => {