@knighted/display-name

A codemod to add displayName to React function components.

• Works with TypeScript or JavaScript source code.
• Quickly fix react/display-name lint errors.
• Use displayName or a named function expression.
• Pass a path to a file, or a string.

Example

Given

import React, { memo } from 'react'

const Foo = memo(({ a }) => {
  return <>{a}</>
})
const Bar = React.forwardRef((props, ref) => <p ref={ref}>bar</p>)
const Baz = memo(
  React.forwardRef((props, ref) => {
    return <p ref={ref}>baz</p>
  }),
)

Then running modify on the source code (or modifyFile on the file path) results in

import React, { memo } from 'react'

const Foo = memo(({ a }) => {
  return <>{a}</>
})
Foo.displayName = 'Foo'
const Bar = React.forwardRef((props, ref) => <p ref={ref}>bar</p>)
Bar.displayName = 'Bar'
const Baz = memo(
  React.forwardRef((props, ref) => {
    return <p ref={ref}>baz</p>
  }),
)

If running the codemod against a codebase that has recently added eslint-plugin-react you can write a script.

import { globSync } from 'node:fs'
import { writeFile } from 'node:fs/promises'
import { modifyFile } from '@knighted/display-name'

const doCodeMod = async () => {
  for (const file of globSync('**/*.tsx', {
    exclude: ['**/node_modules/**', '**/dist/**', '**/build/**'],
  })) {
    await writeFile(file, await modifyFile(file))
  }
}

await doCodeMod()

Then optionally run the results through a formatter like prettier.

Options

There are some options, none are required. Most notably you can choose a style for adding the display name. The default is displayName which adds a displayName property to the function component, or you can choose namedFuncExpr to use a named function expression instead.

type Options = {
  requirePascal?: boolean
  insertSemicolon?: boolean
  modifyNestedForwardRef?: boolean
  style?: 'displayName' | 'namedFuncExpr'
}

For example, using namedFuncExpr

const Foo = memo(() => <>foo</>)

becomes

const Foo = memo(function Foo() {
  return <>foo</>
})