signal?: NodeJS.Signals | null;

};

const LOCAL_EMBEDDING_WORKER_FAILURE_CODES = new Set<string>(

Object.values(LOCAL_EMBEDDING_WORKER_ERROR_CODES),

);

/** Create a local embedding worker failure with stable metadata fields. */

export function createLocalEmbeddingWorkerFailureError(params: {

message: string;

...(params.cause !== undefined ? { cause: params.cause } : {}),

});

}

/** Narrow unknown errors to local embedding worker lifecycle failures. */

export function isLocalEmbeddingWorkerFailure(

err: unknown,

): err is LocalEmbeddingWorkerFailureError {

return (

err instanceof Error &&

LOCAL_EMBEDDING_WORKER_FAILURE_CODES.has(String((err as { code?: unknown }).code))

);

}

// Memory Host SDK tests cover query expansion behavior.

// Memory Host SDK tests cover query keyword extraction behavior.

import { describe, expect, it } from "vitest";

import { expandQueryForFts, extractKeywords } from "./query-expansion.js";

import { extractKeywords } from "./query-expansion.js";

describe("extractKeywords", () => {

it("extracts keywords from English conversational query", () => {

});

});

});

describe("expandQueryForFts", () => {

it("returns original query and extracted keywords", () => {

const result = expandQueryForFts("that API we discussed");

expect(result).toStrictEqual({

original: "that API we discussed",

keywords: ["api", "discussed"],

expanded: "that API we discussed OR api OR discussed",

});

});

it("builds expanded OR query for FTS", () => {

const result = expandQueryForFts("the solution for bugs");

expect(result).toStrictEqual({

original: "the solution for bugs",

keywords: ["solution", "bugs"],

expanded: "the solution for bugs OR solution OR bugs",

});

});

it("returns original query when no keywords extracted", () => {

const result = expandQueryForFts("the");

expect(result).toStrictEqual({

original: "the",

keywords: [],

expanded: "the",

});

});

});

return keywords;

}

/**

* Expand a query for FTS search.

* Returns both the original query and extracted keywords for OR-matching.

*

* @param query - User's original query

* @returns Object with original query and extracted keywords

*/

export function expandQueryForFts(

query: string,

opts?: { ftsTokenizer?: "unicode61" | "trigram" },

): {

original: string;

keywords: string[];

expanded: string;

} {

const original = query.trim();

const keywords = extractKeywords(original, opts);

// Build expanded query: original terms OR extracted keywords

// This ensures both exact matches and keyword matches are found

const expanded = keywords.length > 0 ? `${original} OR ${keywords.join(" OR ")}` : original;

return { original, keywords, expanded };

}