stacker.news/sw/build.js

66 lines
2.2 KiB
JavaScript

const crypto = require('crypto')
const fs = require('fs')
const path = require('path')
const getRevision = filePath => crypto.createHash('md5').update(fs.readFileSync(filePath)).digest('hex')
function formatBytes (bytes, decimals = 2) {
if (bytes === 0) {
return '0 B'
}
const k = 1024
const sizes = ['B', 'KB', 'MB']
const i = Math.floor(Math.log(bytes) / Math.log(k))
const formattedSize = parseFloat((bytes / Math.pow(k, i)).toFixed(decimals))
return `${formattedSize} ${sizes[i]}`
}
function generatePrecacheManifest () {
const manifest = []
let size = 0
const addToManifest = (filePath, url, s) => {
const revision = getRevision(filePath)
manifest.push({ url, revision })
size += s
}
const staticDir = path.join(__dirname, '../public')
const staticFiles = fs.readdirSync(staticDir)
const staticMatch = f => [/\.(gif|jpe?g|ico|png|ttf|webmanifest)$/, /^darkmode\.js$/].some(m => m.test(f))
staticFiles.filter(staticMatch).forEach(file => {
const filePath = path.join(staticDir, file)
const stats = fs.statSync(filePath)
if (stats.isFile()) {
addToManifest(filePath, '/' + file, stats.size)
}
})
const pagesDir = path.join(__dirname, '../pages')
const precacheURLs = ['/offline']
const pagesFiles = fs.readdirSync(pagesDir)
const fileToUrl = f => '/' + f.replace(/\.js$/, '')
const pageMatch = f => precacheURLs.some(url => fileToUrl(f) === url)
pagesFiles.filter(pageMatch).forEach(file => {
const filePath = path.join(pagesDir, file)
const stats = fs.statSync(filePath)
if (stats.isFile()) {
// This is not ideal since dependencies of the pages may have changed
// but we would still generate the same revision ...
// The ideal solution would be to create a revision from the file generated by webpack
// in .next/server/pages but the file may not exist yet when we run this script
addToManifest(filePath, fileToUrl(file), stats.size)
}
})
const output = 'sw/precache-manifest.json'
fs.writeFileSync(output, JSON.stringify(manifest, null, 2))
console.log(`Created precache manifest at ${output}. Cache will include ${manifest.length} URLs with a size of ${formatBytes(size)}.`)
}
module.exports = { generatePrecacheManifest }