Propagate video root identifier from pointer metadata

js/services/commentThreadService.js

@@ -186,7 +186,11 @@ export default class CommentThreadService {
     this.videoKind = normalizeKind(video?.kind);
     this.videoAuthorPubkeyRaw = rawVideoAuthorPubkey;
     this.videoAuthorPubkey = normalizePubkey(rawVideoAuthorPubkey);
-    this.videoRootIdentifier = normalizeString(video?.videoRootId);
+    const pointerRootIdentifier = normalizeString(
+      video?.pointerIdentifiers?.videoRootId,
+    );
+    this.videoRootIdentifier =
+      normalizeString(video?.videoRootId) || pointerRootIdentifier;
     this.videoRootRelay = normalizeRelay(
       video?.videoRootRelay || video?.rootIdentifierRelay,
     );

js/ui/videoModalCommentController.js

@@ -161,7 +161,10 @@ export default class VideoModalCommentController {
     }
     const videoKind = normalizeKind(video.kind);
     const videoAuthorPubkey = normalizeString(video.pubkey);
-    const videoRootId = normalizeString(video.videoRootId);
+    const pointerRootId = normalizeString(
+      video.pointerIdentifiers?.videoRootId,
+    );
+    const videoRootId = normalizeString(video.videoRootId) || pointerRootId;
     const videoRootRelay = normalizeRelay(
       video.videoRootRelay || video.rootIdentifierRelay,
     );
@@ -611,8 +614,13 @@ export default class VideoModalCommentController {
       this.modalCommentState.videoKind || normalizeKind(video.kind);
     const videoAuthorPubkey =
       this.modalCommentState.videoAuthorPubkey || normalizeString(video.pubkey);
+    const fallbackPointerRootId = normalizeString(
+      video.pointerIdentifiers?.videoRootId,
+    );
     const videoRootId =
-      this.modalCommentState.videoRootId || normalizeString(video.videoRootId);
+      this.modalCommentState.videoRootId ||
+      normalizeString(video.videoRootId) ||
+      fallbackPointerRootId;
     const videoRootRelay =
       this.modalCommentState.videoRootRelay ||
       normalizeRelay(video.videoRootRelay || video.rootIdentifierRelay);

tests/comment-thread-service.test.mjs

@@ -509,6 +509,46 @@ test(
   },
 );
 
+test(
+  "CommentThreadService falls back to pointerIdentifiers root id",
+  async () => {
+    const video = {
+      id: "pointer-video",
+      pubkey: "rootpk",
+      kind: 30078,
+      tags: [],
+      pointerIdentifiers: {
+        videoRootId: "pointer-root",
+      },
+    };
+
+    const pointerComment = {
+      id: "comment-pointer",
+      kind: COMMENT_EVENT_KIND,
+      pubkey: "commenter",
+      created_at: 1700000001,
+      content: "Pointer scoped",
+      tags: [["i", "pointer-root"], ["p", "rootpk"]],
+    };
+
+    let fetchTarget = null;
+    const service = new CommentThreadService({
+      nostrClient: { ensurePool: async () => {} },
+      fetchVideoComments: async (target) => {
+        fetchTarget = target;
+        return [pointerComment];
+      },
+      subscribeVideoComments: () => () => {},
+    });
+
+    const snapshot = await service.loadThread({ video });
+
+    assert.ok(fetchTarget, "fetch should run when pointer identifiers are provided");
+    assert.equal(fetchTarget.rootIdentifier, "pointer-root");
+    assert.equal(snapshot.rootIdentifier, "pointer-root");
+  },
+);
+
 test(
   "CommentThreadService preserves raw video author pubkeys during hydration fetches",
   async () => {

tests/video-modal-comments.test.mjs

@@ -407,6 +407,73 @@ test(
   },
 );
 
+test(
+  "VideoModalCommentController uses pointerIdentifiers root id fallback",
+  async () => {
+    const publishCalls = [];
+    const loadTargets = [];
+
+    const controller = new VideoModalCommentController({
+      commentThreadService: {
+        setCallbacks: () => {},
+        teardown: () => {},
+        defaultLimit: 10,
+        loadThread: async (target) => {
+          loadTargets.push(target);
+          return {};
+        },
+        processIncomingEvent: () => {},
+      },
+      videoModal: {
+        setCommentSectionCallbacks: () => {},
+        hideCommentsDisabledMessage: () => {},
+        showCommentsDisabledMessage: () => {},
+        setCommentsVisibility: () => {},
+        clearComments: () => {},
+        resetCommentComposer: () => {},
+        setCommentStatus: () => {},
+        setCommentComposerState: () => {},
+        renderComments: () => {},
+      },
+      auth: {
+        isLoggedIn: () => true,
+      },
+      services: {
+        publishComment: async (payload) => {
+          publishCalls.push(payload);
+          return { ok: true, event: { id: "comment", tags: [] } };
+        },
+      },
+      utils: {
+        normalizeHexPubkey: (value) => value,
+      },
+    });
+
+    const video = {
+      id: "pointer-video",
+      pubkey: "AUTHORPK",
+      enableComments: true,
+      kind: 30078,
+      pointerIdentifiers: {
+        videoRootId: "pointer-root",
+      },
+    };
+
+    controller.load(video);
+    await Promise.resolve();
+
+    assert.equal(loadTargets.length, 1, "loadThread should capture pointer target");
+    assert.equal(loadTargets[0].rootIdentifier, "pointer-root");
+
+    controller.submit({ text: "Pointer fallback" });
+    await controller.modalCommentPublishPromise;
+
+    assert.equal(publishCalls.length, 1, "publishComment should run once");
+    const payload = publishCalls[0];
+    assert.equal(payload.rootIdentifier, "pointer-root");
+  },
+);
+
 test(
   "VideoModalCommentController publishes comment using event id fallback",
   async () => {