feat: dynamic chunk importer

packages/nitro/src/dynamic.ts

@@ -0,0 +1,44 @@
+import { join } from 'path'
+import globby from 'globby'
+
+export async function createDynamicImporter (cwd: string) {
+  const assets = await globby('**/*.js', { cwd, absolute: false })
+  const chunkInfo = {}
+  for (const asset of assets) {
+    const { id, ids, modules } = require(join(cwd, asset))
+    if ((id || ids) && modules) {
+      chunkInfo[asset] = { id, ids, modules: Object.keys(modules) }
+    }
+  }
+
+  return (syncImport, asyncImport) => genRequireDynamic(chunkInfo, syncImport, asyncImport)
+}
+
+export function genRequireDynamic (chunkInfo, syncImport, asyncImport) {
+  return `\nconst _dynamic_chunks = ${JSON.stringify(chunkInfo, null, 2)};
+function requireDynamic (chunkId) {
+  const chunk = _dynamic_chunks[chunkId]
+
+  if (!chunk) {
+    return ${syncImport}
+  }
+
+  const promise = ${asyncImport}
+
+  if (Array.isArray(chunk.modules)) {
+    const modules = {}
+    for (const id of chunk.modules) {
+      modules[id] = function (module, _exports, _require) {
+        module.exports = promise.then(chunk => {
+          const asyncModule = { exports: {}, require: _require }
+          chunk.modules[id](asyncModule, asyncModule.exports, asyncModule.require)
+          return asyncModule.exports
+        })
+      }
+    }
+    chunk.modules = modules
+  }
+
+  return chunk
+};`
+}

packages/nitro/src/nuxt-deploy.ts

@@ -9,6 +9,7 @@ import gzipSize from 'gzip-size'
 import chalk from 'chalk'
 import { getRollupConfig } from './rollup.config'
 import { tryImport, hl, prettyPath } from './utils'
+import { createDynamicImporter } from './dynamic'
 
 async function main () {
   const rootDir = resolve(process.cwd(), process.argv[2] || '.')
@@ -19,6 +20,9 @@ async function main () {
     buildDir: '',
     targets: [],
     nuxt: 2,
+    dynamicImporter: undefined,
+    importSync: "require('../server/' + chunkId)",
+    importAsync: "Promise.resolve(require('../server/' + chunkId))",
     target: process.argv[3] && process.argv[3][0] !== '-' ? process.argv[3] : null,
     minify: process.argv.includes('--minify') ? true : null,
     analyze: process.argv.includes('--analyze') ? true : null,
@@ -44,7 +48,13 @@ async function main () {
   // eslint-disable-next-line no-template-curly-in-string
   const htmlTemplateCompiled = `export default (params) => \`${htmlTemplateContents.replace(/{{ (\w+) }}/g, '${params.$1}')}\``
   await writeFile(htmlTemplateFileJS, htmlTemplateCompiled)
-  consola.info('Generated', (prettyPath(htmlTemplateFileJS)))
+  consola.info('Generated', prettyPath(htmlTemplateFileJS))
+
+  // Collect dynamic chunks
+  if (!config.dynamicImporter) {
+    consola.info('Collecting dynamic chunks...')
+    config.dynamicImporter = await createDynamicImporter(resolve(config.buildDir, 'dist/server'))
+  }
 
   // Bundle for each target
   for (let target of config.targets) {

packages/nitro/src/rollup.config.ts

@@ -53,6 +53,12 @@ export const getRollupConfig = (config) => {
     plugins: []
   }
 
+  if (config.logStartup) {
+    options.output.intro += 'global._startTime = process.hrtime();'
+    // eslint-disable-next-line no-template-curly-in-string
+    options.output.outro += 'global._endTime = process.hrtime(global._startTime); global._coldstart = ((_endTime[0] * 1e9) + _endTime[1]) / 1e6; console.log(`λ Cold start took: ${global._coldstart}ms`);'
+  }
+
   // https://github.com/rollup/plugins/tree/master/packages/replace
   options.plugins.push(replace({
     values: {
@@ -60,15 +66,13 @@ export const getRollupConfig = (config) => {
     }
   }))
 
-  // Preserve dynamic require
+  // Dynamic Importer
-  // https://github.com/rollup/plugins/tree/master/packages/replace
+  if (config.dynamicImporter) {
-  options.output.intro += 'const requireDynamic = require;'
+    options.output.intro += config.dynamicImporter(config.importSync, config.importAsync)
-  options.plugins.push(replace({
+  } else {
-    values: {
+    options.output.intro += 'const requireDynamic = require;'
-      'require("./" +': 'requireDynamic("../server/" +'
+  }
-    },
+  options.plugins.push(replace({ values: { 'require("./" +': 'requireDynamic(' }, delimiters: ['', ''] }))
-    delimiters: ['', '']
-  }))
 
   // https://github.com/rollup/plugins/tree/master/packages/alias
   options.plugins.push(alias({
@@ -109,12 +113,6 @@ export const getRollupConfig = (config) => {
   // https://github.com/rollup/plugins/tree/master/packages/json
   options.plugins.push(json())
 
-  if (config.logStartup) {
-    options.output.intro += 'global._startTime = process.hrtime();'
-    // eslint-disable-next-line no-template-curly-in-string
-    options.output.outro += 'global._endTime = process.hrtime(global._startTime); global._coldstart = ((_endTime[0] * 1e9) + _endTime[1]) / 1e6; console.log(`λ Cold start took: ${global._coldstart}ms`);'
-  }
-
   if (config.analyze) {
     // https://github.com/doesdev/rollup-plugin-analyzer
     options.plugins.push(analyze())

packages/nitro/src/utils.ts

@@ -1,10 +1,12 @@
 import { relative } from 'path'
 import jiti from 'jiti'
 
+const pwd = process.cwd()
+
 export const hl = str => '`' + str + '`'
 
 export const prettyPath = (p, highlight = true) => {
-  p = relative(process.cwd(), p)
+  p = relative(pwd, p)
   return highlight ? hl(p) : p
 }