ESLint v9.29.0 released

Highlights

ECMAScript 2026 Explicit Resource Management

ESLint’s default parser espree now supports new Explicit Resource Management syntax: using and await using declarations, which automatically calls a dispose method when a resource goes out of scope.

if (something) {
    using someResource = getSomeResource();

    // ... use `someResource`

} // dispose `someResource`

async function foo() {
    if (something) {
        await using someResource = getSomeResource();

        // ... use `someResource`

    } // await dispose `someResource`
}

To enable parsing this syntax, set languageOptions.ecmaVersion to 2026 or "latest" (default).

Please note that the core rules have not yet been updated to support this syntax.

New allowProperties option in no-restricted-properties

The no-restricted-properties rule can now be configured to restrict all properties on an object except for specific ones.

/* eslint no-restricted-properties: [2, { "object": "config", "allowProperties": ["settings", "version"] }] */

config.settings = { theme: "dark" }; // ok
config.version = "1.0.0"; // ok

config.apiKey = "12345"; // error
config.timeout = 5000; // error

TypeScript Syntax Support in Core Rules

As announced in the ESLint v9.23.0 release blog post, we are actively working to add TypeScript syntax support to core rules.

ESLint v9.29.0 introduces full TypeScript syntax support for two more core rules. These rules are:

• no-restricted-globals. This rule now ignores references in type annotations.
• no-var. This rule now allows var in global type declarations.

These rules can now be used to lint TypeScript files as well as regular JavaScript. To lint TypeScript code, be sure to use @typescript-eslint/parser, or another compatible parser.

New SourceCode#isGlobalReference(node) method

The SourceCode class has a new method isGlobalReference(node).

It returns true if passed Identifier node references a global variable configured via languageOptions.globals, /* global */ comments, or ecmaVersion, and not declared by a local binding.

const myRule = {
    meta: {
        // ...
    },
    create(context) {
        return {
            Identifier(node) {
                if (context.sourceCode.isGlobalReference(node)) {
                    // do something
                }
            },
        };
    },
};

Other notable changes

• New ECMAScript 2025 global variables Float16Array and Iterator will now be automatically enabled when languageOptions.ecmaVersion is set to 2025 (or higher) or "latest".
• The --prune-suppressions CLI option will now also remove entries for files that no longer exist.
• The includeIgnoreFile() helper function now accepts a second optional name parameter that allows you to set a custom name for the configuration object this function returns.
• The class-methods-use-this rule now supports class auto-accessors. This language feature is part of the Decorators proposal, which is still in stage 3 status, but the auto-accessors syntax is already available in TypeScript.

Features

• f686fcb feat: add ecmaVersion: 2026, parsing using and await using (#19832) (Milos Djermanovic)
• 19cdd22 feat: prune suppressions for non-existent files (#19825) (TKDev7)
• b3d720f feat: add ES2025 globals (#19835) (fisker Cheung)
• 677a283 feat: add auto-accessor fields support to class-methods-use-this (#19789) (sethamus)
• dbba058 feat: allow global type declaration in no-var (#19714) (Remco Haszing)
• 342bd29 feat: ignore type annotations in no-restricted-globals (#19781) (sethamus)
• 786bcd1 feat: add allowProperties option to no-restricted-properties (#19772) (sethamus)
• 05b66d0 feat: add sourceCode.isGlobalReference(node) method (#19695) (Nitin Kumar)

Bug Fixes

• 85c082c fix: explicit matching behavior with negated patterns and arrays (#19845) (Milos Djermanovic)
• 9bda4a9 fix: fix LintOptions.filterCodeBlock types (#19837) (ntnyq)
• 7ab77a2 fix: correct breaking deprecation of FlatConfig type (#19826) (Logicer)
• 1ba3318 fix: add language and dialects to no-use-before-define (#19808) (Francesco Trotta)

Documentation

• 00e3e6a docs: add support for custom name parameter to includeIgnoreFile (#19795) (루밀LuMir)
• 3aed075 docs: Update README (GitHub Actions Bot)
• a2f888d docs: enhance documentation with links and fix typos (#19761) (루밀LuMir)
• 53c3235 docs: update to clarify prompt usage (#19748) (Jennifer Davis)

Chores

• 5c114c9 chore: upgrade @eslint/js@9.29.0 (#19851) (Milos Djermanovic)
• acf2201 chore: package.json update for @eslint/js release (Jenkins)
• a806994 refactor: Remove eslintrc from flat config functionality (#19833) (Nicholas C. Zakas)
• 152ed51 test: switch to flat config mode in code path analysis tests (#19824) (Milos Djermanovic)
• b647239 chore: Update first-party dependencies faster with Renovate (#19822) (Nicholas C. Zakas)
• 7abe42e refactor: SafeEmitter -> SourceCodeVisitor (#19708) (Nicholas C. Zakas)
• e392895 perf: improve time complexity of getLocFromIndex (#19782) (루밀LuMir)
• 0ed289c chore: remove accidentally committed file (#19807) (Francesco Trotta)