@lint-suite/eslint-plugin-no-nested-object-value

An ESLint rule for JavaScript and TypeScript object literals that requires complex property values to be named before use. It reports non-empty nested objects, arrays containing object literals, conditional expressions, and chained calls, helping configuration and data objects keep their top-level values readable.

Compatibility

Requires ESLint ^10.9.1 and TypeScript >=6.0.3. The package is built and tested with Node.js 24.

Installation

pnpm add -D @lint-suite/eslint-plugin-no-nested-object-value eslint@^10.9.1 typescript@^6.0.3 typescript-eslint@^8.69.0

Configuration

The plugin does not configure a parser. This flat config parses the TypeScript examples below:

import plugin from '@lint-suite/eslint-plugin-no-nested-object-value';
import tseslint from 'typescript-eslint';

export default [
  {
    files: ['**/*.ts'],
    languageOptions: { parser: tseslint.parser },
    plugins: { 'no-nested-object-value': plugin },
    rules: { 'no-nested-object-value/no-nested-object-value': 'error' }
  }
];

Options

configFiles defaults to:

['**/*.config.{ts,js,mjs,cjs}', '**/eslint.config.*', '**/*.schema.ts']

Files matching one of these globs are exempt. Replace the list to use different filename exemptions:

rules: {
  'no-nested-object-value/no-nested-object-value': ['error', { configFiles: ['**/generated/**'] }]
}

Scope and exemptions

Object literals used as decorator arguments are exempt. So are files matching configFiles, including the default *.config.ts, eslint.config.*, and *.schema.ts patterns. Empty objects and arrays, arrays without object-literal elements, member access, and a single non-chained call are also exempt. The rule offers a hoisting suggestion only when the property key is a non-computed identifier; string and computed keys are reported without a suggestion.

Examples

Each snippet below is checked by this rule alone, not by an entire ESLint configuration. Examples that depend on a filename or non-default option state that requirement explicitly.

Valid examples

1. Named nested object value

const data = { id: 1 };
const value = { data };

2. Empty nested object

const value = { data: {} };

3. Array of identifiers

const first = 1;
const second = 2;
const value = { items: [first, second] };

4. Single call value

const value = { data: api.load() };

5. Default config-file exemption

// Filename: eslint.config.ts
const config = { rules: { semi: 'error' } };

This is valid because the default configFiles option exempts eslint.config.*.

6. Decorator argument exemption

@Component({ providers: [{ provide: Service, useClass: ServiceImpl }] })
class Feature {}

Invalid examples

1. Non-empty nested object

const value = { data: { id: 1 } };

Name the object before assigning it to data.

2. Array containing an object literal

const value = { items: [{ id: 1 }] };

Name the array before assigning it to items.

3. Conditional property value

const value = { status: ready ? 'ready' : 'waiting' };

Name the conditional result before assigning it to status.

4. Chained call property value

const value = { data: api.load().parse() };

Name the chained-call result before assigning it to data.

5. Nested object with a computed key

const value = { [key]: { id: 1 } };

This is reported, but has no hoisting suggestion because the key is computed.

6. Nested object with a string key

const value = { 'complex-key': { id: 1 } };

This is reported, but has no hoisting suggestion because the key is not an identifier.

The named noNestedObjectValueRule export is for composed plugin registries.