eslint-visitor-keys

Constants and utilities about visitor keys to traverse AST.

💿 Installation

Use npm to install.

$ npm install eslint-visitor-keys

Requirements

📖 Usage

To use in an ESM file:

import * as evk from "eslint-visitor-keys"

To use in a CommonJS file:

const evk = require("eslint-visitor-keys")

evk.KEYS

type: { [type: string]: string[] | undefined }

Visitor keys. This keys are frozen.

This is an object. Keys are the type of ESTree nodes. Their values are an array of property names which have child nodes.

For example:

console.log(evk.KEYS.AssignmentExpression) // → ["left", "right"]

evk.getKeys(node)

type: (node: object) => string[]

Get the visitor keys of a given AST node.

This is similar to Object.keys(node) of ES Standard, but some keys are excluded: parent, leadingComments, trailingComments, and names which start with _.

This will be used to traverse unknown nodes.

For example:

const node = {
    type: "AssignmentExpression",
    left: { type: "Identifier", name: "foo" },
    right: { type: "Literal", value: 0 }
}
console.log(evk.getKeys(node)) // → ["type", "left", "right"]

evk.unionWith(additionalKeys)

type: (additionalKeys: object) => { [type: string]: string[] | undefined }

Make the union set with evk.KEYS and the given keys.

For example:

console.log(evk.unionWith({
    MethodDefinition: ["decorators"]
})) // → { ..., MethodDefinition: ["decorators", "key", "value"], ... }

📰 Change log

See GitHub releases.

🍻 Contributing

Welcome. See ESLint contribution guidelines.

Development commands