index.js

'use strict'

const path = require('path')
const fs = require('fs')
const globby = require('globby')
const crypto = require('crypto')
const { CleanWebpackPlugin } = require('clean-webpack-plugin')
const WorkboxPlugin = require('workbox-webpack-plugin')
const defaultCache = require('./cache')
const buildCustomWorker = require('./build-custom-worker')
const buildFallbackWorker = require('./build-fallback-worker')

const getRevision = file => crypto.createHash('md5').update(fs.readFileSync(file)).digest('hex')

module.exports =
  (pluginOptions = {}) =>
  (nextConfig = {}) =>
    Object.assign({}, nextConfig, {
      webpack(config, options) {
        const {
          webpack,
          buildId,
          dev,
          config: { distDir = '.next', pageExtensions = ['tsx', 'ts', 'jsx', 'js', 'mdx'], experimental = {} }
        } = options

        let basePath = options.config.basePath
        if (!basePath) basePath = '/'

        // For workbox configurations:
        // https://developers.google.com/web/tools/workbox/reference-docs/latest/module-workbox-webpack-plugin.GenerateSW
        const {
          disable = false,
          register = true,
          dest = distDir,
          sw = 'sw.js',
          cacheStartUrl = true,
          dynamicStartUrl = true,
          dynamicStartUrlRedirect,
          skipWaiting = true,
          clientsClaim = true,
          cleanupOutdatedCaches = true,
          additionalManifestEntries,
          ignoreURLParametersMatching = [],
          importScripts = [],
          publicExcludes = ['!noprecache/**/*'],
          buildExcludes = [],
          modifyURLPrefix = {},
          manifestTransforms = [],
          fallbacks = {},
          cacheOnFrontEndNav = false,
          reloadOnOnline = true,
          scope = basePath,
          customWorkerDir = 'worker',
          subdomainPrefix, // deprecated, use basePath in next.config.js instead
          ...workbox
        } = pluginOptions

        if (typeof nextConfig.webpack === 'function') {
          config = nextConfig.webpack(config, options)
        }

        if (disable) {
          options.isServer && console.log('> [PWA] PWA support is disabled')
          return config
        }

        if (subdomainPrefix) {
          console.error(
            '> [PWA] subdomainPrefix is deprecated, use basePath in next.config.js instead: https://nextjs.org/docs/api-reference/next.config.js/basepath'
          )
        }

        console.log(`> [PWA] Compile ${options.isServer ? 'server' : 'client (static)'}`)

        let { runtimeCaching = defaultCache } = pluginOptions
        const _scope = path.posix.join(scope, '/')

        // inject register script to main.js
        const _sw = path.posix.join(basePath, sw.startsWith('/') ? sw : `/${sw}`)
        config.plugins.push(
          new webpack.DefinePlugin({
            __PWA_SW__: `'${_sw}'`,
            __PWA_SCOPE__: `'${_scope}'`,
            __PWA_ENABLE_REGISTER__: `${Boolean(register)}`,
            __PWA_START_URL__: dynamicStartUrl ? `'${basePath}'` : undefined,
            __PWA_CACHE_ON_FRONT_END_NAV__: `${Boolean(cacheOnFrontEndNav)}`,
            __PWA_RELOAD_ON_ONLINE__: `${Boolean(reloadOnOnline)}`
          })
        )

        const registerJs = path.join(__dirname, 'register.js')
        const entry = config.entry
        config.entry = () =>
          entry().then(entries => {
            if (entries['main.js'] && !entries['main.js'].includes(registerJs)) {
              entries['main.js'].unshift(registerJs)
            }
            return entries
          })

        if (!options.isServer) {
          const _dest = path.join(options.dir, dest)
          const customWorkerScriptName = buildCustomWorker({
            id: buildId,
            basedir: options.dir,
            customWorkerDir,
            destdir: _dest,
            plugins: config.plugins.filter(plugin => plugin instanceof webpack.DefinePlugin),
            minify: !dev
          })

          if (!!customWorkerScriptName) {
            importScripts.unshift(customWorkerScriptName)
          }

          if (register) {
            console.log(`> [PWA] Auto register service worker with: ${path.resolve(registerJs)}`)
          } else {
            console.log(
              `> [PWA] Auto register service worker is disabled, please call following code in componentDidMount callback or useEffect hook`
            )
            console.log(`> [PWA]   window.workbox.register()`)
          }

          console.log(`> [PWA] Service worker: ${path.join(_dest, sw)}`)
          console.log(`> [PWA]   url: ${_sw}`)
          console.log(`> [PWA]   scope: ${_scope}`)

          config.plugins.push(
            new CleanWebpackPlugin({
              cleanOnceBeforeBuildPatterns: [
                path.join(_dest, 'workbox-*.js'),
                path.join(_dest, 'worker-*.js.LICENSE.txt'),
                path.join(_dest, 'workbox-*.js.map'),
                path.join(_dest, sw),
                path.join(_dest, `${sw}.map`)
              ]
            })
          )

          // precache files in public folder
          let manifestEntries = additionalManifestEntries
          if (!Array.isArray(manifestEntries)) {
            manifestEntries = globby
              .sync(
                [
                  '**/*',
                  '!workbox-*.js',
                  '!workbox-*.js.map',
                  '!worker-*.js',
                  '!worker-*.js.map',
                  '!fallback-*.js',
                  '!fallback-*.js.map',
                  `!${sw.replace(/^\/+/, '')}`,
                  `!${sw.replace(/^\/+/, '')}.map`,
                  ...publicExcludes
                ],
                {
                  cwd: 'public'
                }
              )
              .map(f => ({
                url: path.posix.join(basePath, `/${f}`),
                revision: getRevision(`public/${f}`)
              }))
          }

          if (cacheStartUrl) {
            if (!dynamicStartUrl) {
              manifestEntries.push({
                url: basePath,
                revision: buildId
              })
            } else if (typeof dynamicStartUrlRedirect === 'string' && dynamicStartUrlRedirect.length > 0) {
              manifestEntries.push({
                url: dynamicStartUrlRedirect,
                revision: buildId
              })
            }
          }

          let _fallbacks = fallbacks
          if (_fallbacks) {
            const res = buildFallbackWorker({
              id: buildId,
              fallbacks,
              basedir: options.dir,
              destdir: _dest,
              minify: !dev,
              pageExtensions
            })

            if (res) {
              _fallbacks = res.fallbacks
              importScripts.unshift(res.name)
              res.precaches.forEach(route => {
                if (!manifestEntries.find(entry => entry.url.startsWith(route))) {
                  manifestEntries.push({
                    url: route,
                    revision: buildId
                  })
                }
              })
            } else {
              _fallbacks = undefined
            }
          }

          const workboxCommon = {
            swDest: path.join(_dest, sw),
            additionalManifestEntries: dev ? [] : manifestEntries,
            exclude: [
              ...buildExcludes,
              ({ asset, compilation }) => {
                if (
                  asset.name.startsWith('server/') ||
                  asset.name.match(/^(build-manifest\.json|react-loadable-manifest\.json)$/)
                ) {
                  return true
                }
                if (dev && !asset.name.startsWith('static/runtime/')) {
                  return true
                }
                if (experimental.modern /* modern */) {
                  if (asset.name.endsWith('.module.js')) {
                    return false
                  }
                  if (asset.name.endsWith('.js')) {
                    return true
                  }
                }
                return false
              }
            ],
            modifyURLPrefix: {
              ...modifyURLPrefix,
              '/_next/../public/': '/'
            },
            manifestTransforms: [
              ...manifestTransforms,
              async (manifestEntries, compilation) => {
                const manifest = manifestEntries.map(m => {
                  m.url = m.url.replace('/_next//static/image', '/_next/static/image')
                  m.url = m.url.replace('/_next//static/media', '/_next/static/media')
                  if (m.revision === null) {
                    let key = m.url
                    if (key.startsWith(config.output.publicPath)) {
                      key = m.url.substring(config.output.publicPath.length)
                    }
                    const assset = compilation.assetsInfo.get(key)
                    m.revision = assset ? assset.contenthash || buildId : buildId
                  }
                  m.url = m.url.replace(/\[/g, '%5B').replace(/\]/g, '%5D')
                  return m
                })
                return { manifest, warnings: [] }
              }
            ]
          }

          if (workbox.swSrc) {
            const swSrc = path.join(options.dir, workbox.swSrc)
            console.log(`> [PWA] Inject manifest in ${swSrc}`)
            config.plugins.push(
              new WorkboxPlugin.InjectManifest({
                ...workboxCommon,
                ...workbox,
                swSrc
              })
            )
          } else {
            if (dev) {
              console.log(
                '> [PWA] Build in develop mode, cache and precache are mostly disabled. This means offline support is disabled, but you can continue developing other functions in service worker.'
              )

              ignoreURLParametersMatching.push(/ts/)
              runtimeCaching = [
                {
                  urlPattern: /.*/i,
                  handler: 'NetworkOnly',
                  options: {
                    cacheName: 'dev'
                  }
                }
              ]
            }

            if (dynamicStartUrl) {
              runtimeCaching.unshift({
                urlPattern: basePath,
                handler: 'NetworkFirst',
                options: {
                  cacheName: 'start-url',
                  plugins: [
                    {
                      cacheWillUpdate: async ({ request, response, event, state }) => {
                        if (response && response.type === 'opaqueredirect') {
                          return new Response(response.body, {
                            status: 200,
                            statusText: 'OK',
                            headers: response.headers
                          })
                        }
                        return response
                      }
                    }
                  ]
                }
              })
            }

            if (_fallbacks) {
              runtimeCaching.forEach(c => {
                if (c.options.precacheFallback) return
                if (Array.isArray(c.options.plugins) && c.options.plugins.find(p => 'handlerDidError' in p)) return
                if (!c.options.plugins) c.options.plugins = []
                c.options.plugins.push({
                  handlerDidError: async ({ request }) => self.fallback(request)
                })
              })
            }

            config.plugins.push(
              new WorkboxPlugin.GenerateSW({
                ...workboxCommon,
                skipWaiting,
                clientsClaim,
                cleanupOutdatedCaches,
                ignoreURLParametersMatching,
                importScripts,
                ...workbox,
                runtimeCaching
              })
            )
          }
        }

        return config
      }
    })