feat(nodejs): make tbl.search chainable (lancedb#1421)

so this was annoying me when writing the docs. 

for a `search` query, one needed to chain `async` calls.

```ts
const res = await (await tbl.search("greetings")).toArray()
```

now the promise will be deferred until the query is collected, leading
to a more functional API

```ts
const res = await tbl.search("greetings").toArray()
```

nodejs/__test__/table.test.ts

@@ -706,10 +706,10 @@ describe("table.search", () => {
     const data = [{ text: "hello world" }, { text: "goodbye world" }];
     const table = await db.createTable("test", data, { schema });
 
-    const results = await table.search("greetings").then((r) => r.toArray());
+    const results = await table.search("greetings").toArray();
     expect(results[0].text).toBe(data[0].text);
 
-    const results2 = await table.search("farewell").then((r) => r.toArray());
+    const results2 = await table.search("farewell").toArray();
     expect(results2[0].text).toBe(data[1].text);
   });
 
@@ -721,7 +721,7 @@ describe("table.search", () => {
     ];
     const table = await db.createTable("test", data);
 
-    expect(table.search("hello")).rejects.toThrow(
+    expect(table.search("hello").toArray()).rejects.toThrow(
       "No embedding functions are defined in the table",
     );
   });

nodejs/lancedb/arrow.ts

@@ -97,7 +97,11 @@ export type TableLike =
   | ArrowTable
   | { schema: SchemaLike; batches: RecordBatchLike[] };
 
-export type IntoVector = Float32Array | Float64Array | number[];
+export type IntoVector =
+  | Float32Array
+  | Float64Array
+  | number[]
+  | Promise<Float32Array | Float64Array | number[]>;
 
 export function isArrowTable(value: object): value is TableLike {
   if (value instanceof ArrowTable) return true;

nodejs/lancedb/embedding/embedding_function.ts

@@ -181,7 +181,7 @@ export abstract class EmbeddingFunction<
   /**
   Compute the embeddings for a single query
  */
-  async computeQueryEmbeddings(data: T): Promise<IntoVector> {
+  async computeQueryEmbeddings(data: T): Promise<Awaited<IntoVector>> {
     return this.computeSourceEmbeddings([data]).then(
       (embeddings) => embeddings[0],
     );

nodejs/lancedb/query.ts

@@ -89,15 +89,26 @@ export interface QueryExecutionOptions {
 }
 
 /** Common methods supported by all query types */
-export class QueryBase<
-  NativeQueryType extends NativeQuery | NativeVectorQuery,
-  QueryType,
-> implements AsyncIterable<RecordBatch>
+export class QueryBase<NativeQueryType extends NativeQuery | NativeVectorQuery>
+  implements AsyncIterable<RecordBatch>
 {
-  protected constructor(protected inner: NativeQueryType) {
+  protected constructor(
+    protected inner: NativeQueryType | Promise<NativeQueryType>,
+  ) {
     // intentionally empty
   }
 
+  // call a function on the inner (either a promise or the actual object)
+  protected doCall(fn: (inner: NativeQueryType) => void) {
+    if (this.inner instanceof Promise) {
+      this.inner = this.inner.then((inner) => {
+        fn(inner);
+        return inner;
+      });
+    } else {
+      fn(this.inner);
+    }
+  }
   /**
    * A filter statement to be applied to this query.
    *
@@ -110,16 +121,16 @@ export class QueryBase<
    * Filtering performance can often be improved by creating a scalar index
    * on the filter column(s).
    */
-  where(predicate: string): QueryType {
-    this.inner.onlyIf(predicate);
-    return this as unknown as QueryType;
+  where(predicate: string): this {
+    this.doCall((inner: NativeQueryType) => inner.onlyIf(predicate));
+    return this;
   }
   /**
    * A filter statement to be applied to this query.
    * @alias where
    * @deprecated Use `where` instead
    */
-  filter(predicate: string): QueryType {
+  filter(predicate: string): this {
     return this.where(predicate);
   }
 
@@ -155,7 +166,7 @@ export class QueryBase<
    */
   select(
     columns: string[] | Map<string, string> | Record<string, string> | string,
-  ): QueryType {
+  ): this {
     let columnTuples: [string, string][];
     if (typeof columns === "string") {
       columns = [columns];
@@ -167,8 +178,10 @@ export class QueryBase<
     } else {
       columnTuples = Object.entries(columns);
     }
-    this.inner.select(columnTuples);
-    return this as unknown as QueryType;
+    this.doCall((inner: NativeQueryType) => {
+      inner.select(columnTuples);
+    });
+    return this;
   }
 
   /**
@@ -177,15 +190,19 @@ export class QueryBase<
    * By default, a plain search has no limit.  If this method is not
    * called then every valid row from the table will be returned.
    */
-  limit(limit: number): QueryType {
-    this.inner.limit(limit);
-    return this as unknown as QueryType;
+  limit(limit: number): this {
+    this.doCall((inner: NativeQueryType) => inner.limit(limit));
+    return this;
   }
 
   protected nativeExecute(
     options?: Partial<QueryExecutionOptions>,
   ): Promise<NativeBatchIterator> {
-    return this.inner.execute(options?.maxBatchLength);
+    if (this.inner instanceof Promise) {
+      return this.inner.then((inner) => inner.execute(options?.maxBatchLength));
+    } else {
+      return this.inner.execute(options?.maxBatchLength);
+    }
   }
 
   /**
@@ -214,7 +231,13 @@ export class QueryBase<
   /** Collect the results as an Arrow @see {@link ArrowTable}. */
   async toArrow(options?: Partial<QueryExecutionOptions>): Promise<ArrowTable> {
     const batches = [];
-    for await (const batch of new RecordBatchIterable(this.inner, options)) {
+    let inner;
+    if (this.inner instanceof Promise) {
+      inner = await this.inner;
+    } else {
+      inner = this.inner;
+    }
+    for await (const batch of new RecordBatchIterable(inner, options)) {
       batches.push(batch);
     }
     return new ArrowTable(batches);
@@ -258,8 +281,8 @@ export interface ExecutableQuery {}
  *
  * This builder can be reused to execute the query many times.
  */
-export class VectorQuery extends QueryBase<NativeVectorQuery, VectorQuery> {
-  constructor(inner: NativeVectorQuery) {
+export class VectorQuery extends QueryBase<NativeVectorQuery> {
+  constructor(inner: NativeVectorQuery | Promise<NativeVectorQuery>) {
     super(inner);
   }
 
@@ -286,7 +309,8 @@ export class VectorQuery extends QueryBase<NativeVectorQuery, VectorQuery> {
    * you the desired recall.
    */
   nprobes(nprobes: number): VectorQuery {
-    this.inner.nprobes(nprobes);
+    super.doCall((inner) => inner.nprobes(nprobes));
+
     return this;
   }
 
@@ -300,7 +324,7 @@ export class VectorQuery extends QueryBase<NativeVectorQuery, VectorQuery> {
    * whose data type is a fixed-size-list of floats.
    */
   column(column: string): VectorQuery {
-    this.inner.column(column);
+    super.doCall((inner) => inner.column(column));
     return this;
   }
 
@@ -321,7 +345,7 @@ export class VectorQuery extends QueryBase<NativeVectorQuery, VectorQuery> {
   distanceType(
     distanceType: Required<IvfPqOptions>["distanceType"],
   ): VectorQuery {
-    this.inner.distanceType(distanceType);
+    super.doCall((inner) => inner.distanceType(distanceType));
     return this;
   }
 
@@ -355,7 +379,7 @@ export class VectorQuery extends QueryBase<NativeVectorQuery, VectorQuery> {
    * distance between the query vector and the actual uncompressed vector.
    */
   refineFactor(refineFactor: number): VectorQuery {
-    this.inner.refineFactor(refineFactor);
+    super.doCall((inner) => inner.refineFactor(refineFactor));
     return this;
   }
 
@@ -380,7 +404,7 @@ export class VectorQuery extends QueryBase<NativeVectorQuery, VectorQuery> {
    * factor can often help restore some of the results lost by post filtering.
    */
   postfilter(): VectorQuery {
-    this.inner.postfilter();
+    super.doCall((inner) => inner.postfilter());
     return this;
   }
 
@@ -394,13 +418,13 @@ export class VectorQuery extends QueryBase<NativeVectorQuery, VectorQuery> {
    * calculate your recall to select an appropriate value for nprobes.
    */
   bypassVectorIndex(): VectorQuery {
-    this.inner.bypassVectorIndex();
+    super.doCall((inner) => inner.bypassVectorIndex());
     return this;
   }
 }
 
 /** A builder for LanceDB queries. */
-export class Query extends QueryBase<NativeQuery, Query> {
+export class Query extends QueryBase<NativeQuery> {
   constructor(tbl: NativeTable) {
     super(tbl.query());
   }
@@ -443,7 +467,37 @@ export class Query extends QueryBase<NativeQuery, Query> {
    * a default `limit` of 10 will be used.  @see {@link Query#limit}
    */
   nearestTo(vector: IntoVector): VectorQuery {
-    const vectorQuery = this.inner.nearestTo(Float32Array.from(vector));
-    return new VectorQuery(vectorQuery);
+    if (this.inner instanceof Promise) {
+      const nativeQuery = this.inner.then(async (inner) => {
+        if (vector instanceof Promise) {
+          const arr = await vector.then((v) => Float32Array.from(v));
+          return inner.nearestTo(arr);
+        } else {
+          return inner.nearestTo(Float32Array.from(vector));
+        }
+      });
+      return new VectorQuery(nativeQuery);
+    }
+    if (vector instanceof Promise) {
+      const res = (async () => {
+        try {
+          const v = await vector;
+          const arr = Float32Array.from(v);
+          //
+          // biome-ignore lint/suspicious/noExplicitAny: we need to get the `inner`, but js has no package scoping
+          const value: any = this.nearestTo(arr);
+          const inner = value.inner as
+            | NativeVectorQuery
+            | Promise<NativeVectorQuery>;
+          return inner;
+        } catch (e) {
+          return Promise.reject(e);
+        }
+      })();
+      return new VectorQuery(res);
+    } else {
+      const vectorQuery = this.inner.nearestTo(Float32Array.from(vector));
+      return new VectorQuery(vectorQuery);
+    }
   }
 }

nodejs/lancedb/remote/table.ts

@@ -122,9 +122,8 @@ export class RemoteTable extends Table {
   query(): import("..").Query {
     throw new Error("query() is not yet supported on the LanceDB cloud");
   }
-  search(query: IntoVector): VectorQuery;
-  search(query: string): Promise<VectorQuery>;
-  search(_query: string | IntoVector): VectorQuery | Promise<VectorQuery> {
+
+  search(_query: string | IntoVector): VectorQuery {
     throw new Error("search() is not yet supported on the LanceDB cloud");
   }
   vectorSearch(_vector: unknown): import("..").VectorQuery {

nodejs/lancedb/table.ts

@@ -244,9 +244,9 @@ export abstract class Table {
    * Create a search query to find the nearest neighbors
    * of the given query vector
    * @param {string} query - the query. This will be converted to a vector using the table's provided embedding function
-   * @rejects {Error} If no embedding functions are defined in the table
+   * @note  If no embedding functions are defined in the table, this will error when collecting the results.
    */
-  abstract search(query: string): Promise<VectorQuery>;
+  abstract search(query: string): VectorQuery;
   /**
    * Create a search query to find the nearest neighbors
    * of the given query vector
@@ -502,28 +502,26 @@ export class LocalTable extends Table {
   query(): Query {
     return new Query(this.inner);
   }
-
-  search(query: string): Promise<VectorQuery>;
-
-  search(query: IntoVector): VectorQuery;
-  search(query: string | IntoVector): Promise<VectorQuery> | VectorQuery {
+  search(query: string | IntoVector): VectorQuery {
     if (typeof query !== "string") {
       return this.vectorSearch(query);
     } else {
-      return this.getEmbeddingFunctions().then(async (functions) => {
-        // TODO: Support multiple embedding functions
-        const embeddingFunc: EmbeddingFunctionConfig | undefined = functions
-          .values()
-          .next().value;
-        if (!embeddingFunc) {
-          return Promise.reject(
-            new Error("No embedding functions are defined in the table"),
-          );
-        }
-        const embeddings =
-          await embeddingFunc.function.computeQueryEmbeddings(query);
-        return this.query().nearestTo(embeddings);
-      });
+      const queryPromise = this.getEmbeddingFunctions().then(
+        async (functions) => {
+          // TODO: Support multiple embedding functions
+          const embeddingFunc: EmbeddingFunctionConfig | undefined = functions
+            .values()
+            .next().value;
+          if (!embeddingFunc) {
+            return Promise.reject(
+              new Error("No embedding functions are defined in the table"),
+            );
+          }
+          return await embeddingFunc.function.computeQueryEmbeddings(query);
+        },
+      );
+
+      return this.query().nearestTo(queryPromise);
     }
   }