eslint-scope

library9.1.2jsnpmunverified

ESLint Scope is the ECMAScript scope analyzer used in ESLint, forked from escope. The current stable version is 9.1.2, with regular releases as part of the ESLint monorepo. It analyzes ESTree-compliant ASTs to produce a ScopeManager with variable scopes, references, and definitions. Key differentiators include deep integration with ESLint, support for JSX, modern ECMAScript features, and both ESM and CommonJS module analysis. It ships with TypeScript types since v9.1.0 and requires Node.js ^20.19.0 || ^22.13.0 || >=24.

testing

npm install eslint-scope

github ↗package ↗

INSTALL

IMPORT

SIG · ESLINT-SCOPE

eslint-scope

testingjavascriptv9.1.2

Install

—

Import

—

Disk

—

Pass rate

0/ 6

Env Coverage0 / 6

glibc

18–22

musl

18–22

Install & Compatibility

Where this runs

tested against v? · npm install

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

node 18–226 runs

build_error

glibc

node 18–226 runs

build_error

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

eslintScope

✓ import * as eslintScope from 'eslint-scope'

✗ import eslintScope from 'eslint-scope'

ESM uses namespace import; default import does not exist.

eslintScope

✓ const eslintScope = require('eslint-scope')

✗ const { analyze } = require('eslint-scope')

CommonJS requires the full module; destructuring works but namespace import is preferred in ESM.

ScopeManager

✓ import type { ScopeManager } from 'eslint-scope'

✗ import { ScopeManager } from 'eslint-scope'

ScopeManager is a type, not a value; use type import in TypeScript.

Scope

✓ import type { Scope } from 'eslint-scope'

✗ const { Scope } = require('eslint-scope')

Scope is an interface; cannot be required as a value.

Parses JavaScript code with espree, analyzes scopes with eslint-scope, and logs global and function scope variables.

import * as eslintScope from 'eslint-scope'; import * as espree from 'espree'; const code = `const x = 1; function foo() { var y = 2; }`; const ast = espree.parse(code, { ecmaVersion: 2022, sourceType: 'script' }); const scopeManager = eslintScope.analyze(ast, { ecmaVersion: 2022 }); console.log(scopeManager.scopes.length); // 2 console.log(scopeManager.globalScope.variables.map(v => v.name)); // ['x', 'foo'] const functionScope = scopeManager.acquire(ast.body[1]); console.log(functionScope.variables.map(v => v.name)); // ['y']

Debug

Known issues

breakingRequires Node.js ^20.19.0 || ^22.13.0 || >=24 as of v9.0.0

fix

Update Node.js to a supported version (20.19.0+, 22.13.0+, or 24+).

affects: >=9.0.0

breakingDefault export removed; use namespace import (ESM) or require (CJS)

fix

Change 'import eslintScope from "eslint-scope"' to 'import * as eslintScope from "eslint-scope"'.

affects: >=5.0.0

gotchaScopeManager.acquire() may return null for nodes that do not introduce a scope

fix

Always check that the return value is not null before using it.

affects: *

deprecatedThe 'optimistic' option is experimental and may be removed in future versions

fix

Avoid relying on optimistic scope analysis; use default behavior.

affects: >=7.0.0

gotchaECMAScript version must match the parser's ecmaVersion; mismatches may cause incorrect scope analysis

fix

Provide the same ecmaVersion to both the parser and eslint-scope.analyze().

affects: *

Errors

Common errors & fixes

TypeError: eslintScope.analyze is not a function

Using default import instead of namespace import in ESM

fix

Replace 'import eslintScope from "eslint-scope"' with 'import * as eslintScope from "eslint-scope"'.

Cannot find module 'eslint-scope'

Package not installed or wrong import path when using CommonJS with .mjs extension

fix

Ensure 'eslint-scope' is listed in package.json dependencies and run npm install. For .mjs files, use ESM import syntax.

TypeError: scopeManager.acquire is not a function

Calling acquire on a Scope object instead of ScopeManager

fix

Use scopeManager.acquire(node), not scope.acquire(node).

Error: The 'sourceType' option must be "script" or "module"

Providing an invalid sourceType value

fix

Set sourceType to either "script" or "module" (e.g., sourceType: "module").

Upgrade

Version history

9.1.2latest on npm

Audit

Dependencies

esrecurserequiredused internally for AST traversal

estraverserequiredused internally for AST traversal

Agent activity

4 hits · last 30 days

node

Resources

githubhttps://github.com/eslint/js ↗

packagehttps://www.npmjs.com/package/eslint-scope ↗