polyfills

packages/next/client/dev/amp-dev.js

 /* globals __webpack_hash__ */
-import fetch from 'unfetch'
+import fetch from 'next/dist/build/polyfills/unfetch'
 import EventSourcePolyfill from './event-source-polyfill'
 import { getEventSourceWrapper } from './error-overlay/eventsource'
 import { setupPing } from './on-demand-entries-utils'

packages/next/client/dev/error-overlay/hot-dev-client.js

@@ -28,9 +28,9 @@ SOFTWARE.
 import { getEventSourceWrapper } from './eventsource'
 import formatWebpackMessages from './format-webpack-messages'
 import * as ErrorOverlay from 'react-error-overlay'
-import stripAnsi from 'strip-ansi'
+import stripAnsi from 'next/dist/compiled/strip-ansi'
 import { rewriteStacktrace } from './source-map-support'
-import fetch from 'unfetch'
+import fetch from 'next/dist/build/polyfills/unfetch'
 
 // This alternative WebpackDevServer combines the functionality of:
 // https://github.com/webpack/webpack-dev-server/blob/webpack-1/client/index.js

packages/next/client/dev/event-source-polyfill.js

@@ -2,7 +2,7 @@
 // Improved version of https://github.com/Yaffle/EventSource/
 // Available under MIT License (MIT)
 // Only tries to support IE11 and nothing below
-import fetch from 'unfetch'
+import fetch from 'next/dist/build/polyfills/unfetch'
 
 var document = window.document
 var Response = window.Response

packages/next/client/dev/on-demand-entries-utils.js

 /* global location */
 
-import fetch from 'unfetch'
+import fetch from 'next/dist/build/polyfills/unfetch'
 import { getEventSourceWrapper } from './error-overlay/eventsource'
 
 let evtSource

packages/next/client/index.js

@@ -21,7 +21,7 @@ import {
 
 if (!('finally' in Promise.prototype)) {
   // eslint-disable-next-line no-extend-native
-  Promise.prototype.finally = require('finally-polyfill')
+  Promise.prototype.finally = require('next/dist/build/polyfills/finally-polyfill.min')
 }
 
 const data = JSON.parse(document.getElementById('__NEXT_DATA__').textContent)

packages/next/client/polyfills.js

-import '@next/polyfill-nomodule'
+import 'next/dist/build/polyfills/polyfill-nomodule'

packages/next/package.json

@@ -59,13 +59,11 @@
   "dependencies": {
     "@ampproject/toolbox-optimizer": "2.0.1",
     "@babel/runtime": "7.7.2",
-    "@next/polyfill-nomodule": "9.3.4-canary.0",
     "autodll-webpack-plugin": "0.4.2",
     "cache-loader": "4.1.0",
     "css-loader": "3.3.0",
     "cssnano-simple": "1.0.0",
     "file-loader": "4.2.0",
-    "finally-polyfill": "0.1.0",
     "fork-ts-checker-webpack-plugin": "3.1.1",
     "ignore-loader": "0.1.2",
     "jest-worker": "24.9.0",
@@ -86,7 +84,6 @@
     "style-loader": "1.0.0",
     "styled-jsx": "3.2.5",
     "thread-loader": "2.1.3",
-    "unfetch": "4.1.0",
     "url": "0.11.0",
     "use-subscription": "1.1.1",
     "watchpack": "2.0.0-beta.13",
@@ -115,6 +112,7 @@
     "@babel/preset-react": "7.7.0",
     "@babel/preset-typescript": "7.7.2",
     "@babel/types": "7.7.4",
+    "@next/polyfill-nomodule": "9.3.4-canary.0",
     "@taskr/clear": "1.1.0",
     "@taskr/esnext": "1.1.0",
     "@taskr/watch": "1.1.0",
@@ -173,6 +171,7 @@
     "dotenv-expand": "5.1.0",
     "escape-string-regexp": "2.0.0",
     "etag": "1.8.1",
+    "finally-polyfill": "0.1.0",
     "find-up": "4.0.0",
     "fresh": "0.5.2",
     "gzip-size": "5.1.1",
@@ -198,6 +197,7 @@
     "terser": "4.4.2",
     "text-table": "0.2.0",
     "typescript": "3.7.3",
+    "unfetch": "4.1.0",
     "unistore": "3.4.1"
   },
   "engines": {

packages/next/taskfile.js

 const notifier = require('node-notifier')
 const relative = require('path').relative
 
+export async function next__polyfill_nomodule(task, opts) {
+  await task
+    .source(
+      opts.src ||
+        relative(__dirname, require.resolve('@next/polyfill-nomodule'))
+    )
+    .target('dist/build/polyfills')
+}
+
+export async function finally_polyfill(task, opts) {
+  await task
+    .source(
+      opts.src || relative(__dirname, require.resolve('finally-polyfill'))
+    )
+    .target('dist/build/polyfills')
+}
+
+export async function unfetch(task, opts) {
+  await task
+    .source(opts.src || relative(__dirname, require.resolve('unfetch')))
+    .target('dist/build/polyfills')
+}
+
+export async function browser_polyfills(task) {
+  await task.parallel([
+    'next__polyfill_nomodule',
+    'finally_polyfill',
+    'unfetch',
+  ])
+}
+
 const externals = {
   '@babel/core': 'next/dist/compiled/babel--core',
   '@babel/helper-plugin-utils': 'next/dist/compiled/babel--helper-plugin-utils',
@@ -553,6 +584,7 @@ export async function ncc_unistore(task, opts) {
 
 export async function precompile(task) {
   await task.parallel([
+    'browser_polyfills',
     'ncc_amphtml_validator',
     'ncc_arg',
     'ncc_async_retry',