Upgrade Guide
Next.js 9’s dynamic routes are automatically configured on Vercel and do not require any vercel.json
customization.
You can read more about .
Check your Custom (pages/_app.js
)
If you previously copied the example, you may be able to remove your getInitialProps
.
Removing getInitialProps
from pages/_app.js
(when possible) is important to leverage new Next.js features!
The following getInitialProps
does nothing and may be removed:
Breaking Changes
Next.js will now ignore usage @zeit/next-typescript
and warn you to remove it. Please remove this plugin from your next.config.js
.
Remove references to @zeit/next-typescript/babel
from your custom .babelrc
(if present).
Usage of fork-ts-checker-webpack-plugin
should also be removed from your next.config.js
.
The following types are different:
From:
import { NextContext } from 'next'
import { NextAppContext, DefaultAppIProps } from 'next/app'
import { NextDocumentContext, DefaultDocumentIProps } from 'next/document'
to
import { NextPageContext } from 'next'
You may no longer export a custom variable named config
from a page (i.e. export { config }
/ export const config ...
). This exported variable is now used to specify page-level Next.js configuration like Opt-in AMP and API Route features.
You must rename a non-Next.js-purposed config
export to something different.
next/dynamic
no longer renders “loading…” by default while loading
Dynamic components will not render anything by default while loading. You can still customize this behavior by setting the loading
property:
Next.js now has the concept of page-level configuration, so the withAmp
higher-order component has been removed for consistency.
curl -L https://github.com/vercel/next-codemod/archive/master.tar.gz | tar -xz --strip=2 next-codemod-master/transforms/withamp-to-config.js npx jscodeshift -t ./withamp-to-config.js pages/**/*.js
To perform this migration by hand, or view what the codemod will produce, see below:
Before
import { withAmp } from 'next/amp'
function Home() {
return <h1>My AMP Page</h1>
}
export default withAmp(Home)
// or
export default withAmp(Home, { hybrid: true })
After
next export
no longer exports pages as index.html
Previously, exporting pages/about.js
would result in out/about/index.html
. This behavior has been changed to result in out/about.html
.
You can revert to the previous behavior by creating a next.config.js
with the following content:
// next.config.js
module.exports = {
trailingSlash: true,
}
Pages in ./pages/api/
are now considered API Routes. Pages in this directory will no longer contain a client-side bundle.
next/dynamic
has deprecated loading multiple modules at once
The ability to load multiple modules at once has been deprecated in next/dynamic
to be closer to React’s implementation (React.lazy
and Suspense
).
Updating code that relies on this behavior is relatively straightforward! We’ve provided an example of a before/after to help you migrate your application:
import dynamic from 'next/dynamic'
const HelloBundle = dynamic({
modules: () => {
Hello1: () => import('../components/hello1').then((m) => m.default),
Hello2: () => import('../components/hello2').then((m) => m.default),
}
return components
},
render: (props, { Hello1, Hello2 }) => (
<div>
<h1>{props.title}</h1>
<Hello1 />
<Hello2 />
</div>
),
})
function DynamicBundle() {
return <HelloBundle title="Dynamic Bundle" />
}
export default DynamicBundle
After