Introduction

ESLint Plugin Command is a special kind of ESLint plugin, that by default, does nothing. Instead of checking for code quality, it serves as a micro-codemod tool triggers by special comments on-demand, resuse the infrastructure of ESLint.

For example, one of the built-in commands, /// to-function allows you to convert a single arrow function expression to a function declaration.

/// to-function
const foo = async <T>(msg: T): void => {
  console.log(msg)
}

Will be transformed to this when you hit save with your editor or run eslint . --fix. After executing the command, the comment will also be removed along with the transformation:

async function foo<T>(msg: T): void {
  console.log(msg)
}

One more example that /// to-promis-all converts a sequence of await expressions to await Promise.all():

/// to-promise-all
const foo = await bar().then
const { get } = await import('lodash-es')

Will be transformed to:

const [
  foo,
  { get },
] = await Promise.all([
  bar(),
  import('lodash-es'),
] as const)

Built-in Commands

There is a few list of built-in commands for quick references

• /// keep-sorted - keep an object/array/interface always sorted
• /// to-function - converts an arrow function to a normal function
• /// to-arrow - converts a normal function to an arrow function
• /// to-for-each - converts a for-in/for-of loop to .forEach()
• /// to-for-of - converts a .forEach() to a for-of loop
• /// to-promise-all - converts a sequence of await exps to await Promise.all()
• /// to-string-literal - converts a template literal to a string concatenation
• /// to-template-literal - converts a string concatenation to a template literal
• ... and more, check the sidebar for the full list