eslint-visitor-keys
Advanced tools
Package description
The eslint-visitor-keys package is designed to provide a list of keys that ESLint uses to visit properties in an Abstract Syntax Tree (AST). This is particularly useful for developers working on tools that need to manipulate or analyze JavaScript code, as it helps in navigating the structure of the code in a predictable manner.
Retrieving Visitor Keys
This feature allows you to retrieve a comprehensive list of visitor keys used by ESLint. These keys represent the properties of AST nodes that ESLint will traverse. The code sample demonstrates how to import and log the visitor keys.
const visitorKeys = require('eslint-visitor-keys').KEYS;
console.log(visitorKeys);Union With Custom Keys
This feature enables the combination of ESLint's default visitor keys with custom keys defined by the user. This is useful for tools that work with custom syntax or AST nodes not covered by the default set. The code sample shows how to merge custom keys with the default ones.
const { unionWith } = require('eslint-visitor-keys');
const customKeys = { CustomNode: ['property'] };
const combinedKeys = unionWith(customKeys);
console.log(combinedKeys);Estraverse is a package for traversing JavaScript ASTs. It provides similar functionality to eslint-visitor-keys by allowing the traversal of AST nodes. However, estraverse focuses more on the traversal mechanism itself, including entering and leaving nodes, whereas eslint-visitor-keys primarily provides a list of keys for traversal.
Acorn-walk is a syntax tree walker for the acorn AST format. Similar to eslint-visitor-keys, it aids in the navigation and analysis of ASTs. The key difference is that acorn-walk is tied to the acorn parser's AST format and provides walker functions for different node types, while eslint-visitor-keys offers a more generalized set of keys for any tool that works with JavaScript ASTs.
Changelog
3.4.1 (2023-05-05)
v3.4.0 - March 27, 2023
e9a070f fix: remove useless sourcemap url (fixes #43) (#44) (余腾靖)0398109 chore: add triage action (#42) (Milos Djermanovic)bcffbe5 ci: add Node v19 (#41) (Milos Djermanovic)c24f2e4 chore: update github actions and add funding field (#40) (Deepshika S)81c0732 build: add node v18 (#39) (唯然)6ece4bd feat: add JSXSpreadChild and tool to build keys out of AST definitions (#36) (Brett Zamir)4beb7a7 docs: update badges (#37) (Milos Djermanovic)v3.3.0 - February 11, 2022
7f10327 feat: Bundle JSDoc-built TypeScript declaration file (#34) (Brett Zamir)v3.2.0 - January 15, 2022
5c53218 feat: add missing JSXOpeningFragment and JSXClosingFragment (#33) (Richard Huang)2a5c9a6 docs: readme add syntax highlighting (#32) (coderaiser)v3.1.0 - November 8, 2021
5e3e687 build: upgrade eslint-release to v3.2.0 to support conventional commits (#31) (Milos Djermanovic)53d3939 Build: add node v17 (#30) (唯然)5f5b232 Update: add StaticBlock (#29) (Milos Djermanovic)e89bff9 Chore: use actions/setup-node@v2 (薛定谔的猫)7b756cd Docs: Update the minimum Node.js version requirement (#26) (0uep)v3.0.0 - June 24, 2021
701b67d Breaking: drop node v10/v13/v15 (refs eslint/eslint#14023) (#23) (薛定谔的猫)f584b12 Breaking: Switch to ESM (#24) (Brett Zamir)7279e73 Build: Update branch reference in CI (#25) (Milos Djermanovic)c6846d6 Upgrade: eslint-release (#21) (Nicholas C. Zakas)v2.1.0 - May 3, 2021
908fdf8 Update: add PrivateIdentifier and PropertyDefinition (#20) (Toru Nagashima)2d7be11 Chore: No longer test in Node.js 13 (#17) (Michaël De Boey)b41b509 Docs: Update required Node.js version (#15) (Michaël De Boey)v2.0.0 - August 14, 2020
fb86ca3 Breaking: drop support for Node <10 (#13) (Kai Cataldo)69383b3 Chore: move to GitHub Actions (#14) (Kai Cataldo)v1.3.0 - June 19, 2020
c92dd7f Update: add ChainExpression node (#12) (Toru Nagashima)v1.2.0 - June 4, 2020
21f28bf Update: added exported in exportAllDeclaration key (#10) (Anix)v1.1.0 - August 13, 2019
9331cc0 Update: add ImportExpression (#8) (Toru Nagashima)5967f58 Chore: add supported Node.js versions to CI (#7) (Kai Cataldo)6f7c60f Upgrade: eslint-release@1.0.0 (#5) (Teddy Katz)v1.0.0 - December 18, 2017
v0.1.0 - November 17, 2017
repository field in package.json (#3) (Toru Nagashima)Readme
Constants and utilities about visitor keys to traverse AST.
Use npm to install.
$ npm install eslint-visitor-keys
^12.22.0, ^14.17.0, or >=16.0.0To use in an ESM file:
import * as evk from "eslint-visitor-keys"
To use in a CommonJS file:
const evk = require("eslint-visitor-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"]
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"]
type:
(additionalKeys: object) => { [type: string]: string[] | undefined }
Make the union set with evk.KEYS and the given keys.
additionalKeys is at first, then evk.KEYS is concatenated after that.For example:
console.log(evk.unionWith({
MethodDefinition: ["decorators"]
})) // → { ..., MethodDefinition: ["decorators", "key", "value"], ... }
See GitHub releases.
Welcome. See ESLint contribution guidelines.
npm test runs tests and measures code coverage.npm run lint checks source codes with ESLint.npm run coverage opens the code coverage report of the previous test with your default browser.npm run release publishes this package to npm registory.FAQs
Constants and utilities about visitor keys to traverse AST.
The npm package eslint-visitor-keys receives a total of 50,773,817 weekly downloads. As such, eslint-visitor-keys popularity was classified as popular.
We found that eslint-visitor-keys demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago. It has 2 open source maintainers collaborating on the project.
Did you know?
Socket for GitHub automatically highlights issues in each pull request and monitors the health of all your open source dependencies. Discover the contents of your packages and block harmful activity before you install or update your dependencies.
Security News
Socket CEO Feross Aboukhadijeh joins a16z partners to discuss how modern, sophisticated supply chain attacks require AI-driven defenses and explore the challenges and solutions in leveraging AI for threat detection early in the development life cycle.
Security News
NIST's new AI Risk Management Framework aims to enhance the security and reliability of generative AI systems and address the unique challenges of malicious AI exploits.
Security News
This episode of the Risky Biz podcast discusses how the rise of small open source packages and the shift towards individual maintainers makes the ecosystem more vulnerable to supply chain attacks.