Handle empty/null post embeddings for similar posts and createPost

Avoid pgvector error when query vector is empty; persist null instead of
[] when embedding computation fails; align types with nullable embeddings.

Made-with: Cursor

Author: Xhether

src/models/PostModel.ts

@@ -49,7 +49,7 @@ export class PostModel {
   archive: boolean;
 
   @Column("float", { array: true, nullable: true })
-  embedding: number[];
+  embedding: number[] | null;
 
   @ManyToOne(() => UserModel, (user) => user.posts, { onDelete: "CASCADE" })
   @JoinColumn({ name: "userId" })

src/repositories/PostRepository.ts

@@ -90,7 +90,7 @@ export class PostRepository extends AbstractRepository<PostModel> {
     price: number,
     images: string[],
     user: UserModel,
-    embedding: number[],
+    embedding: number[] | null,
   ): Promise<PostModel> {
     const post = new PostModel();
     post.title = title;
@@ -561,6 +561,9 @@ export class PostRepository extends AbstractRepository<PostModel> {
     excludeUserId: string,
     limit = 20,
   ): Promise<PostModel[]> {
+    if (!Array.isArray(queryEmbedding) || queryEmbedding.length === 0) {
+      return [];
+    }
     const lit = `[${queryEmbedding.join(",")}]`;
     return await this.repository
       .createQueryBuilder("post")
@@ -583,6 +586,9 @@ export class PostRepository extends AbstractRepository<PostModel> {
     excludeUserId: string,
     limit = 10,
   ): Promise<PostModel[]> {
+    if (!Array.isArray(embedding) || embedding.length === 0) {
+      return [];
+    }
     const lit = `[${embedding.join(",")}]`;
     return await this.repository
       .createQueryBuilder("post")
@@ -703,6 +709,9 @@ export class PostRepository extends AbstractRepository<PostModel> {
     excludeUserId: string,
     limit = 10,
   ): Promise<PostModel[]> {
+    if (!Array.isArray(avgEmbedding) || avgEmbedding.length === 0) {
+      return [];
+    }
     const lit = `[${avgEmbedding.join(",")}]`;
     return await this.repository
       .createQueryBuilder("post")

src/services/PostService.ts

@@ -114,14 +114,26 @@ export class PostService {
         console.error("Error computing embedding:", error);
         embedding = null;
       }
-      const freshPost = await postRepository.createPost(post.title, post.description, categories, eventTags, post.condition, post.originalPrice, images, user, (embedding ?? []) as number[]);
-      if (embedding && Array.isArray(embedding) && embedding.length > 0) {
+      const validEmbedding =
+        Array.isArray(embedding) && embedding.length > 0 ? embedding : null;
+      const freshPost = await postRepository.createPost(
+        post.title,
+        post.description,
+        categories,
+        eventTags,
+        post.condition,
+        post.originalPrice,
+        images,
+        user,
+        validEmbedding,
+      );
+      if (validEmbedding) {
         const requestRepository = Repositories.request(
           transactionalEntityManager,
         );
         // TODO: how many should we get?
         const similarRequests = await requestRepository.findSimilarRequests(
-          embedding,
+          validEmbedding,
           user.firebaseUid,
           10,
         );
@@ -584,9 +596,12 @@ export class PostService {
       const postRepository = Repositories.post(transactionalEntityManager);
       const post = await postRepository.getPostById(params.id);
       if (!post) throw new NotFoundError("Post not found!");
-      const embedding = post.embedding;
+      const embedding =
+        Array.isArray(post.embedding) && post.embedding.length > 0
+          ? post.embedding
+          : null;
 
-      if (embedding == null) {
+      if (!embedding) {
         let fallback = await postRepository.getSimilarPostsFallback(
           post.id,
           user.firebaseUid,

src/types/ApiResponses.ts

@@ -93,7 +93,7 @@ export interface Post {
   categories: Category[];
   eventTags: EventTag[];
   sold: boolean;
-  embedding: number[];
+  embedding: number[] | null;
 }
 
 export interface GetPostsResponse {
@@ -157,7 +157,7 @@ export interface Request {
   title: string;
   description: string;
   archive: boolean;
-  embedding: number[];
+  embedding: number[] | null;
   user: PrivateProfile;
   matches: PostModel[];
 }