Custom docfx template to replace search library from `lunr.js` to `fuse.js`

README.md

Summary

This script is used to replace docfx's lunr.js search to fuse.js based search. To use this script. simply replace public/search-worker.min.js with this gist content.

Note

This script works only when using modern template. To support default template. it needs to replace import Fuse from statement with equivalent code that don't use ESM.

search-worker.min.js

"use strict";

import Fuse from 'https://cdn.jsdelivr.net/npm/fuse.js@latest/+esm'

let fuseIndex
let searchData

// See: https://www.fusejs.io/api/options.html
const fuseOptions = {
  threshold: 0.0,
  minMatchCharLength: 1,
  ignoreLocation: true,
  useExtendedSearch: true,
  keys: [
    { name: 'href',     weight: 0.8 },
    { name: 'title',    weight: 0.8 },
    { name: 'keywords', weight: 0.5 }
  ]
};

onmessage = oEvent => {
  const q = oEvent.data.q
  let results = []
  if (fuseIndex) {
    const hits = fuseIndex.search(q)
    results = hits.map((hit) => {
      const item = hit.item
      return {
        href: item.href,
        title: item.title,
        keywords: item.keywords
      }
    })
  }
  postMessage({ e: "query-ready", q, d: results })
}

async function buildIndex() {
  // Try to load pre-generated search index
  const response = await fetch("../index.fuse.json")    
  if(response.ok)
  {
    const json = await response.json()
    const index = Fuse.parseIndex(json)
    fuseIndex = new Fuse(null, fuseOptions, index)
  }
  else
  {
    const response = await fetch("../index.json")
    if(!response.ok)
      return
  
    var json = await response.json()
    searchData = Object.values(json) // Convert to items.
    if (searchData && searchData.length > 0) {     
        fuseIndex = new Fuse(searchData, fuseOptions)
    }
  }
  postMessage({ e: "index-ready" })
}

await buildIndex()