Algolia tie-breaking sort

What is it?

This package is a simple and fast post-processing sorting of search results coming from Algolia, with zero dependency. Original idea and implementation from mikaa123!

When should it be used?

The main use-case for this is to re-rank an Algolia result set after it has been returned by the search engine. Such need could happen if you want to merge results coming from different indices, or if you have a complex ranking strategy that needs 2 layers of sorting (Algolia has advanced result-tweaking solutions, but can only apply one global ranking strategy).

For the most performance-conscious people, a quick benchmark with Array.prototype.sort() and Node.js v16.2.0 showed that the function can sort 5000 results in less than 50 milliseconds.

How to use it?

Regular install through npm or yarn:

npm i algolia-tiebreaking-sort
# or
yarn add algolia-tiebreaking-sort

Then the most straightforward way to use it is the following:

const algoliasearch = require('algoliasearch')
const tieBreakingSort = require('algolia-tiebreaking-sort')

const client = algoliasearch('APPID', 'APIKEY')
const index1 = client.initIndex('index_name_1')
const index2 = client.initIndex('index_name_2')

// Only requirement is to have `_rankingInfo` and `objectID` for each hit
const search1 = index1.search('my query', { getRankingInfo: true })
const search2 = index2.search('my query', { getRankingInfo: true })

Promise.all([search1, search2]).then(results => {
  const hits = [...results[0].hits, ...results[1].hits]
  console.log(hits.sort(tieBreakingSort))
})

What are the next steps?

Potential improvements include:

• Handle sort-by criteria
• Make the ranking formula configurable, allowing custom ones
• Optimize speed
• Rewrite in Typescript

How to run tests?

Just clone this repository and run:

npm test
# or
yarn test

Disclaimer

This package is not officially supported by Algolia, so it cannot be held responsible for any use in production. If you need support, use GitHub issues or the community forum, but not Algolia email support.