import del from 'del' import { cpus } from 'os' import { fork } from 'child_process' import cp from 'recursive-copy' import mkdirp from 'mkdirp-then' import { resolve, join } from 'path' import { existsSync, readFileSync } from 'fs' import loadConfig from 'next-server/next-config' import { PHASE_EXPORT, SERVER_DIRECTORY, PAGES_MANIFEST, CONFIG_FILE, BUILD_ID_FILE, CLIENT_STATIC_FILES_PATH } from 'next-server/constants' import { setAssetPrefix } from 'next-server/asset' import * as envConfig from 'next-server/config' import createProgress from 'tty-aware-progress' export default async function (dir, options, configuration) { function log (message) { if (options.silent) return console.log(message) } dir = resolve(dir) const nextConfig = configuration || loadConfig(PHASE_EXPORT, dir) const concurrency = options.concurrency || 10 const threads = options.threads || Math.max(cpus().length - 1, 1) const distDir = join(dir, nextConfig.distDir) log(`> using build directory: ${distDir}`) if (!existsSync(distDir)) { throw new Error(`Build directory ${distDir} does not exist. Make sure you run "next build" before running "next start" or "next export".`) } const buildId = readFileSync(join(distDir, BUILD_ID_FILE), 'utf8') const pagesManifest = require(join(distDir, SERVER_DIRECTORY, PAGES_MANIFEST)) const pages = Object.keys(pagesManifest) const defaultPathMap = {} for (const page of pages) { // _document and _app are not real pages. if (page === '/_document' || page === '/_app') { continue } if (page === '/_error') { defaultPathMap['/404.html'] = { page } continue } defaultPathMap[page] = { page } } // Initialize the output directory const outDir = options.outdir await del(join(outDir, '*')) await mkdirp(join(outDir, '_next', buildId)) // Copy static directory if (existsSync(join(dir, 'static'))) { log(' copying "static" directory') await cp( join(dir, 'static'), join(outDir, 'static'), { expand: true } ) } // Copy .next/static directory if (existsSync(join(distDir, CLIENT_STATIC_FILES_PATH))) { log(' copying "static build" directory') await cp( join(distDir, CLIENT_STATIC_FILES_PATH), join(outDir, '_next', CLIENT_STATIC_FILES_PATH) ) } // Get the exportPathMap from the config file if (typeof nextConfig.exportPathMap !== 'function') { console.log(`> No "exportPathMap" found in "${CONFIG_FILE}". Generating map from "./pages"`) nextConfig.exportPathMap = async (defaultMap) => { return defaultMap } } // Start the rendering process const renderOpts = { dir, buildId, nextExport: true, assetPrefix: nextConfig.assetPrefix.replace(/\/$/, ''), distDir, dev: false, staticMarkup: false, hotReloader: null } const {serverRuntimeConfig, publicRuntimeConfig} = nextConfig if (publicRuntimeConfig) { renderOpts.runtimeConfig = publicRuntimeConfig } envConfig.setConfig({ serverRuntimeConfig, publicRuntimeConfig }) // set the assetPrefix to use for 'next/asset' setAssetPrefix(renderOpts.assetPrefix) // We need this for server rendering the Link component. global.__NEXT_DATA__ = { nextExport: true } log(` launching ${threads} threads with concurrency of ${concurrency} per thread`) const exportPathMap = await nextConfig.exportPathMap(defaultPathMap, {dev: false, dir, outDir, distDir, buildId}) const exportPaths = Object.keys(exportPathMap) const progress = !options.silent && createProgress(exportPaths.length) const chunks = exportPaths.reduce((result, route, i) => { const worker = i % threads if (!result[worker]) { result[worker] = { paths: [], pathMap: {} } } result[worker].pathMap[route] = exportPathMap[route] result[worker].paths.push(route) return result }, []) await Promise.all( chunks.map( chunk => new Promise((resolve, reject) => { const worker = fork(require.resolve('./worker'), [], { env: process.env }) worker.send({ distDir, buildId, exportPaths: chunk.paths, exportPathMap: chunk.pathMap, outDir, renderOpts, concurrency }) worker.on('message', ({ type, payload }) => { if (type === 'progress' && progress) { progress() } else if (type === 'error') { reject(payload) } else if (type === 'done') { resolve() } }) }) ) ) // Add an empty line to the console for the better readability. log('') }