Sketch of combiners for MiniSearch results of different searches

minisearch-combiners.js

/**
* Usage:
*
* import { and, or } from 'minisearch-combiner'
*
* and(resultsA, resultsB)
*
* or(resultsA, resultsB)
*
* and(or(resultsA, resultsB), resultsC)
*
*/

const or = (a, b) => {
  return sortByScore(Object.values(a.concat(b).reduce((byId, result) => {
    if (byId[result.id] == null) {
      byId[result.id] = {
        ...result,
        match: { ...result.match }
      }
    } else {
      byId[result.id].score += result.score
      Object.assign(byId[result.id].match, result.match)
    }

    return byId
  }, {})))
}

const and = (a, b) => {
  const aById = a.reduce((byId, result) => {
    byId[result.id] = result
    return byId
  }, {})

  return sortByScore(b.reduce((results, result) => {
    const other = aById[result.id]

    if (other != null) {
      results.push({
        ...result,
        score: result.score + other.score,
        match: { ...result.match, ...other.match }
      })
    }
    return results
  }, []))
}

const sortByScore = (results) =>
  results.sort(({ score: a }, { score: b }) => a < b ? 1 : -1)