feat: precompile assets on build

.gitignore

@@ -9,3 +9,4 @@ css/**/*.css
 yarn.lock
 cypress/videos/*
 /public/styles/octicons/octicons.html
+/precompiled/

lib/i18n.js

@@ -2,7 +2,8 @@ require('require-yaml')
 
 const i18n = require('electron-i18n')
 const flat = require('flat')
-const { get, set } = require('lodash')
+const get = require('lodash/get')
+const set = require('lodash/set')
 const locales = Object.keys(i18n.locales)
 const websiteStrings = require('../data/locale.yml')
 const websiteKeys = Object.keys(flat(websiteStrings))

middleware/browserify-opts.js

@@ -0,0 +1,25 @@
+const nodeModulesToAvoidBabelifying = [
+  'lodash',
+  'lunr',
+  'prettydate'
+]
+
+const excludeRegex = new RegExp(`/node_modules/(${nodeModulesToAvoidBabelifying.join('|')})`)
+
+module.exports = function doBrowserify (browserify) {
+  return function (entry) {
+    return browserify(entry, {
+      transform: [
+        ['babelify', {
+          global: true,
+          exclude: excludeRegex,
+          presets: [
+            ['@babel/preset-env', { targets: '> 0.25%, not dead' }]
+          ]
+        }],
+        'brfs'
+      ]
+    })
+  }
+}
+

middleware/browserify.js

@@ -1,26 +1,4 @@
 const browserify = require('browserify-middleware')
+const browserifyOptions = require('./browserify-opts')
 
-const nodeModulesToAvoidBabelifying = [
-  'lodash',
-  'lunr',
-  'prettydate'
-]
-
-const excludeRegex = new RegExp(`/node_modules/(${nodeModulesToAvoidBabelifying.join('|')})`)
-
-function babelifyMiddleware (entry) {
-  return browserify(entry, {
-    transform: [
-      ['babelify', {
-        global: true,
-        exclude: excludeRegex,
-        presets: [
-          ['@babel/preset-env', { targets: '> 0.25%, not dead' }]
-        ]
-      }],
-      'brfs'
-    ]
-  })
-}
-
-module.exports = babelifyMiddleware
+module.exports = browserifyOptions(browserify)

package.json

@@ -15,10 +15,12 @@
     "release": "node script/release",
     "dev": "cross-env NODE_PATH=. NODE_ENV=development nodemon server.js",
     "prepack": "check-for-leaks",
+    "precompile-assets": "cross-env NODE_ENV=production node script/precompile-assets.js",
     "linkschecker": "NODE_PATH=. NODE_ENV=test node scripts/links-checker.js",
     "cypress": "cypress run",
     "lint": "standard --fix",
-    "generate-octicons": "node ./script/generate-octicons.js"
+    "generate-octicons": "node ./script/generate-octicons.js",
+    "heroku-postbuild": "npm run precompile-assets"
   },
   "husky": {
     "hooks": {
@@ -99,6 +101,7 @@
     "standard": "^12.0.1",
     "supertest": "^3.4.2",
     "supertest-session": "^3.3.0",
+    "uglify-js": "^3.4.9",
     "wait-on": "^3.1.0",
     "walk-sync": "^1.1.3"
   },

script/integration.sh

@@ -1,3 +1,4 @@
+npm run precompile-assets
 npm start &
 wait-on http://localhost:5000
 cypress run --record --key a0cba5c6-0650-4abe-8d41-d990bb7a0a66

script/precompile-assets.js

@@ -0,0 +1,90 @@
+const path = require('path')
+const stream = require('stream')
+const fs = require('fs-extra')
+const browserify = require('browserify')
+const browserifyOptions = require('../middleware/browserify-opts')
+const sass = require('node-sass')
+const uglify = require('uglify-js')
+
+function dir (...parts) {
+  return path.join(__dirname, '..', ...parts)
+}
+
+function uglifyStream () {
+  const buffers = []
+  return new stream.Transform({
+    transform (chunk, _encoding, callback) {
+      buffers.push(chunk)
+      callback()
+    },
+
+    flush (callback) {
+      const code = Buffer.concat(buffers).toString()
+      const compiled = uglify.minify(code)
+      this.push(compiled.code)
+      callback()
+    }
+  })
+}
+
+const PATHS = {
+  precompiled: dir('precompiled'),
+  scripts: dir('precompiled', 'scripts'),
+  styles: dir('precompiled', 'styles'),
+  nodeModules: dir('node_modules'),
+
+  jsEntry: dir('scripts', 'index.js'),
+  jsDestination: dir('precompiled', 'scripts', 'index.js'),
+
+  cssEntry: dir('public', 'styles', 'index.scss'),
+  cssDestination: dir('precompiled', 'styles', 'index.css')
+}
+
+async function precompileAssets () {
+  try {
+    console.log('Creating directories...')
+    await fs.remove(PATHS.precompiled)
+    await fs.ensureDir(PATHS.scripts)
+    await fs.ensureDir(PATHS.styles)
+    console.log('Precompiling JS...')
+    await precompileJavaScript()
+    console.log('Precompiling CSS...')
+    await precompileCss()
+  } catch (err) {
+    console.error(err)
+    process.exit(1)
+  }
+}
+
+function precompileJavaScript () {
+  return new Promise((resolve, reject) => {
+    const b = browserifyOptions(browserify)(PATHS.jsEntry)
+    const pipe = b.bundle()
+      .pipe(uglifyStream())
+      .pipe(fs.createWriteStream(PATHS.jsDestination))
+    pipe.on('error', reject)
+    pipe.on('finish', resolve)
+  })
+}
+
+function precompileCss () {
+  return new Promise((resolve, reject) => {
+    sass.render({
+      file: PATHS.cssEntry,
+      includePaths: [
+        PATHS.nodeModules
+      ]
+    }, async function onSassCompiled (err, result) {
+      if (err) {
+        return reject(err)
+      }
+
+      await fs.writeFile(PATHS.cssDestination, result.css)
+      resolve()
+    })
+  })
+}
+
+if (require.main === module) {
+  precompileAssets()
+}

scripts/apply-active-class-to-active-links.js

@@ -1,4 +1,4 @@
-const { escapeRegExp } = require('lodash')
+const escapeRegExp = require('lodash/escapeRegExp')
 
 module.exports = function applyActiveClassToActiveLinks () {
   const topPath = `/${location.pathname.split('/')[1]}`

scripts/create-filter-list.js

@@ -1,4 +1,4 @@
-const { debounce } = require('lodash')
+const debounce = require('lodash/debounce')
 const lunr = require('lunr')
 const queryString = require('query-string')
 const setQueryString = require('set-query-string')

scripts/lazy-load-images.js

@@ -1,4 +1,4 @@
-const { throttle } = require('lodash')
+const throttle = require('lodash/throttle')
 
 function inViewport (element) {
   const { top, right, bottom, left } = element.getBoundingClientRect()

server.js

@@ -45,8 +45,14 @@ app.set('views', path.join(__dirname, '/views'))
 app.use(nakedRedirect(true, 'www', 302))
 app.use(compression())
 app.use(helmet())
-app.use(sass())
-app.use('/scripts/index.js', browserify('scripts/index.js'))
+if (process.env.NODE_ENV === 'production') {
+  console.log('Production app detected; serving JS and CSS from disk')
+  app.use(express.static(path.join(__dirname, 'precompiled'), { redirect: false }))
+} else {
+  console.log('Dev app detected; compiling JS and CSS in memory')
+  app.use(sass())
+  app.use('/scripts/index.js', browserify('scripts/index.js'))
+}
 app.get('/service-worker.js', (req, res) => res.sendFile(path.resolve(__dirname, 'scripts', 'service-worker.js')))
 app.use(cookieParser())
 app.use(requestLanguage({

test/localization.js

@@ -8,7 +8,7 @@ const fs = require('fs')
 const path = require('path')
 const walk = require('walk-sync')
 const flat = require('flat')
-const getProp = require('lodash').get
+const getProp = require('lodash/get')
 
 const locale = require(path.join(__dirname, '../data/locale.yml'))
 const views = walk.entries(path.join(__dirname, '../views'))