# Next.js Codemods

当一个特性被弃用时，Next.js提供了Codemod转换来帮助升级你的Next.js代码库。

Codemods are transformations that run on your codebase programmatically. This allows for a large amount of changes to be applied without having to manually go through every file.

# Usage

npx @next/codemod <transform> <path>

transform- name of transform, see available transforms below.
path- files or directory to transform
--dryDo a dry-run, no code will be edited
--printPrints the changed output for comparison

# Next.js 11

# cra-to-next (experimental)

Migrates a Create React App project to Next.js; creating a pages directory and necessary config to match behavior. Client-side only rendering is leveraged initially to prevent breaking compatibility due to windowusage during SSR and can be enabled seamlessly to allow gradual adoption of Next.js specific features.

Please share any feedback related to this transform in this discussion .

# Next.js 10

# add-missing-react-import

Transforms files that do not import Reactto include the import in order for the new React JSX transform to work.

For example:

// my-component.js
export default class Home extends React.Component {
  render() {
    return <div>Hello World</div>
  }
}

Transforms into:

// my-component.js
import React from 'react'
export default class Home extends React.Component {
  render() {
    return <div>Hello World</div>
  }
}

# Next.js 9

# name-default-component

Transforms anonymous components into named components to make sure they work with Fast Refresh .

For example:

// my-component.js
export default function () {
  return <div>Hello World</div>
}

Transforms into:

// my-component.js
export default function MyComponent() {
  return <div>Hello World</div>
}

The component will have a camel cased name based on the name of the file, and it also works with arrow functions.

# Usage

Go to your project

cd path-to-your-project/

Run the codemod:

npx @next/codemod name-default-component

# withamp-to-config

Transforms the withAmpHOC into Next.js 9 page configuration.

For example:

// Before
import { withAmp } from 'next/amp'

function Home() {
  return <h1>My AMP Page</h1>
}

export default withAmp(Home)

// After
export default function Home() {
  return <h1>My AMP Page</h1>
}

export const config = {
  amp: true,
}

# Usage

Go to your project

cd path-to-your-project/

Run the codemod:

npx @next/codemod withamp-to-config

# Next.js 6

# url-to-withrouter

Transforms the deprecated automatically injected urlproperty on top level pages to using withRouterand the routerproperty it injects. Read more here: https://nextjs.org/docs/messages/url-deprecated

For example:

// From
import React from 'react'
export default class extends React.Component {
  render() {
    const { pathname } = this.props.url
    return <div>Current pathname: {pathname}</div>
  }
}

// To
import React from 'react'
import { withRouter } from 'next/router'
export default withRouter(
  class extends React.Component {
    render() {
      const { pathname } = this.props.router
      return <div>Current pathname: {pathname}</div>
    }
  }
)

This is one case. All the cases that are transformed (and tested) can be found in the __testfixtures__ directory .

# Usage

Go to your project

cd path-to-your-project/

Run the codemod:

npx @next/codemod url-to-withrouter

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