@typescript-eslint/utils

AST Utilities

AST Utilities provide functions to work with Abstract Syntax Tree (AST) nodes. These utilities can help in identifying node types, such as checking if a node is an identifier or a literal, which is useful when writing custom ESLint rules.

import { ASTUtils } from '@typescript-eslint/utils';
const { isIdentifier, isLiteral } = ASTUtils;

Type Checking

This feature allows rule developers to access TypeScript's type checker, enabling them to perform more sophisticated analyses, such as type inference or type checking, within their custom ESLint rules.

import { ESLintUtils } from '@typescript-eslint/utils';
const { getParserServices } = ESLintUtils;
const parserServices = getParserServices(context);
const checker = parserServices.program.getTypeChecker();

ESLint Rule Creation

Provides a utility for creating ESLint rules with a consistent structure and metadata. This is particularly useful for developers creating custom rules for projects that use TypeScript.

import { ESLintUtils } from '@typescript-eslint/utils';
const createRule = ESLintUtils.RuleCreator(name => `https://example.com/rule/${name}`);
const myRule = createRule({
  name: 'my-custom-rule',
  meta: { /* rule metadata */ },
  defaultOptions: [],
  create(context) { /* rule implementation */ }
});