Precomputed index returns no results

[GonzaloZiadi]

Same as #524. Copying over from there with slight tweaks.

Describe the bug

Empty results when loading precomputed index.

Version

6.5.3

Is this a regression?

don't know

🔬Minimal Reproduction

const Fuse = require('fuse.js');
const fs = require('fs');

const datasets = [{"title":2},{"title":3}];
const options = {
  keys: ['title']
};
var myIndex = Fuse.createIndex(options.keys, datasets);

fs.writeFileSync('./index.json', JSON.stringify(myIndex.toJSON()));

const fuse = new Fuse(datasets, options, myIndex);

var search_term = process.argv[2];
var result = fuse.search(search_term);
console.log(result);
console.log(myIndex);

Additional context

The last print shows that docs, keys, records is empty, if loaded from the precomputed index.

[GonzaloZiadi]

Nope, I was wrong. This is a bug on me.

Full working code:

// build step
const csvDatabaseFileName = "database.csv";
const fuseIndexName = "fuse-index.json";
const jsonDatabaseName = "database.json";

const csvString = fs.readFileSync(csvDatabaseFileName).toString();

// See https://www.papaparse.com/docs
const papaJson = Papa.parse(csvString, {
  header: true,
  dynamicTyping: true
});
const headers = papaJson["meta"]["fields"];
const json = papaJson["data"];

fs.writeFileSync(jsonDatabaseName, JSON.stringify(papaJson));

// See https://fusejs.io/api/indexing.html
const fuseIndex = Fuse.createIndex(headers, json);
fs.writeFileSync(fuseIndexName, JSON.stringify(fuseIndex.toJSON()));

// index.html (within script tag)
async function start() {
  const fuseIndexJson = await fetch(fuseIndexName)
      .then(response => response.json());
  const fuseIndex = Fuse.parseIndex(fuseIndexJson);

  const json = await fetch(jsonDatabaseName)
      .then(response => response.json());

  const options = {
    includeScore: true,
    keys: json["meta"]["fields"]
  };
  const fuse = new Fuse(json["data"], options, fuseIndex);

  console.log(fuse.search("<pattern>"));
}

start();

Summary

1. Read in the CSV file
2. Convert the CSV file to JSON using PapaParse and write the outputted JSON to file
3. Precompute the Fuse index and write it to file
4. Parse the index within script in HTML file, perform search

[GonzaloZiadi]

Sorry about that and thanks for this great library