FlexSearch Document index add and search: working versions (tested 2026-10-15)

{
  "name": "flexsearch-document-index",
  "private": true,
  "type": "module",
  "scripts": {
    "test": "node --import tsx --test test/*.test.ts"
  },
  "dependencies": {
    "flexsearch": "0.8.212"
  },
  "devDependencies": {
    "@types/node": "26.6.5",
    "tsx": "4.23.15",
    "@types/flexsearch": "0.7.42"
  }
}

import { Document } from "flexsearch";

export type Article = { id: number; title: string; content: string };

export function createArticleIndex() {
  return new Document<Article>({
    document: {
      id: "id",
      index: ["title", "content"],
      store: true,
    },
  });
}

export function addArticles(index: Document<Article>, articles: Article[]) {
  for (const a of articles) index.add(a);
}

export function searchArticles(index: Document<Article>, query: string) {
  const raw = index.search(query, { enrich: true, limit: 10 }) as Array<{
    field: string;
    result: Array<{ id: number; doc: Article }>;
  }>;
  const ids = new Set<number>();
  const docs: Article[] = [];
  for (const field of raw) {
    for (const hit of field.result ?? []) {
      if (!ids.has(hit.id)) {
        ids.add(hit.id);
        docs.push(hit.doc);
      }
    }
  }
  return docs;
}

import { test } from "node:test";
import assert from "node:assert/strict";
import { addArticles, createArticleIndex, searchArticles } from "../src/index-docs.ts";

test("indexes documents and returns enriched hits", () => {
  const index = createArticleIndex();
  addArticles(index, [
    { id: 1, title: "TypeScript tips", content: "Use strict null checks" },
    { id: 2, title: "Rust ownership", content: "Borrow checker basics" },
  ]);
  const hits = searchArticles(index, "TypeScript");
  assert.ok(hits.some((h) => h.id === 1));
  assert.ok(hits.every((h) => typeof h.title === "string"));
});

test("content field is searchable", () => {
  const index = createArticleIndex();
  addArticles(index, [
    { id: 10, title: "Guide", content: "borrow checker basics for beginners" },
  ]);
  const hits = searchArticles(index, "borrow");
  assert.equal(hits.length, 1);
  assert.equal(hits[0].id, 10);
});