import Server from 'next-server/dist/server/next-server' import { join } from 'path' import HotReloader from './hot-reloader' import {route} from 'next-server/dist/server/router' import {PHASE_DEVELOPMENT_SERVER} from 'next-server/constants' import ErrorDebug from './error-debug' export default class DevServer extends Server { constructor (options) { super(options) this.renderOpts.dev = true this.renderOpts.ErrorDebug = ErrorDebug this.devReady = new Promise(resolve => { this.setDevReady = resolve }) } currentPhase () { return PHASE_DEVELOPMENT_SERVER } readBuildId () { return 'development' } async addExportPathMapRoutes () { // Makes `next export` exportPathMap work in development mode. // So that the user doesn't have to define a custom server reading the exportPathMap if (this.nextConfig.exportPathMap) { console.log('Defining routes from exportPathMap') const exportPathMap = await this.nextConfig.exportPathMap({}, {dev: true, dir: this.dir, outDir: null, distDir: this.distDir, buildId: this.buildId}) // In development we can't give a default path mapping for (const path in exportPathMap) { const {page, query = {}} = exportPathMap[path] // We use unshift so that we're sure the routes is defined before Next's default routes this.router.add({ match: route(path), fn: async (req, res, params, parsedUrl) => { const { query: urlQuery } = parsedUrl Object.keys(urlQuery) .filter(key => query[key] === undefined) .forEach(key => console.warn(`Url defines a query parameter '${key}' that is missing in exportPathMap`)) const mergedQuery = {...urlQuery, ...query} await this.render(req, res, page, mergedQuery, parsedUrl) } }) } } } async prepare () { this.hotReloader = new HotReloader(this.dir, { config: this.nextConfig, buildId: this.buildId }) await super.prepare() await this.addExportPathMapRoutes() await this.hotReloader.start() this.setDevReady() } async close () { if (this.hotReloader) { await this.hotReloader.stop() } } async run (req, res, parsedUrl) { await this.devReady const {finished} = await this.hotReloader.run(req, res, parsedUrl) if (finished) { return } return super.run(req, res, parsedUrl) } generateRoutes () { const routes = super.generateRoutes() // In development we expose all compiled files for react-error-overlay's line show feature // We use unshift so that we're sure the routes is defined before Next's default routes routes.unshift({ match: route('/_next/development/:path*'), fn: async (req, res, params) => { const p = join(this.distDir, ...(params.path || [])) await this.serveStatic(req, res, p) } }) return routes } async renderToHTML (req, res, pathname, query) { const compilationErr = await this.getCompilationError(pathname) if (compilationErr) { res.statusCode = 500 return this.renderErrorToHTML(compilationErr, req, res, pathname, query) } // In dev mode we use on demand entries to compile the page before rendering try { await this.hotReloader.ensurePage(pathname) } catch (err) { if (err.code === 'ENOENT') { res.statusCode = 404 return this.renderErrorToHTML(null, req, res, pathname, query) } if (!this.quiet) console.error(err) } return super.renderToHTML(req, res, pathname, query) } async renderErrorToHTML (err, req, res, pathname, query) { const compilationErr = await this.getCompilationError(pathname) if (compilationErr) { res.statusCode = 500 return super.renderErrorToHTML(compilationErr, req, res, pathname, query) } try { const out = await super.renderErrorToHTML(err, req, res, pathname, query) return out } catch (err2) { if (!this.quiet) console.error(err2) res.statusCode = 500 return super.renderErrorToHTML(err2, req, res, pathname, query) } } sendHTML (req, res, html) { // In dev, we should not cache pages for any reason. res.setHeader('Cache-Control', 'no-store, must-revalidate') return super.sendHTML(req, res, html) } setImmutableAssetCacheControl (res) { res.setHeader('Cache-Control', 'no-store, must-revalidate') } async getCompilationError (page) { const errors = await this.hotReloader.getCompilationErrors(page) if (errors.length === 0) return // Return the very first error we found. return errors[0] } }