@lint-suite/eslint-plugin-max-condition-operands

This ESLint rule for TypeScript limits the number of logical operands in an if condition. Use it to keep authorization, state, and eligibility decisions small enough to name or review easily.

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-max-condition-operands 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-max-condition-operands';
import tseslint from 'typescript-eslint';

export default [
  {
    files: ['**/*.ts'],
    languageOptions: { parser: tseslint.parser },
    plugins: { 'max-condition-operands': plugin },
    rules: { 'max-condition-operands/max-condition-operands': 'error' }
  }
];

Options

max is the maximum number of operands in an if condition. It defaults to 3 and must be an integer of at least 1.

rules: {
  'max-condition-operands/max-condition-operands': ['error', { max: 2 }]
}

Examples

Each snippet is checked by max-condition-operands alone, using the default max: 3 unless noted otherwise.

Valid examples

1. Use one operand

if (isReady) {}

A non-logical condition counts as one operand.

2. Use two operands

if (isReady && hasAccess) {}

Two operands are within the default maximum.

3. Use three operands

if (isReady && hasAccess && isVisible) {}

Three is the default limit.

4. Put a longer expression outside an if

const canPublish = isReady && hasAccess && isVisible && isCurrent;

Only if conditions are checked.

5. Use four operands in a while

while (isReady && hasAccess && isVisible && isCurrent) {}

while conditions are outside this rule's scope.

Invalid examples

1. Use four AND operands

if (a && b && c && d) {}

Four operands exceed the default maximum of three.

2. Use four OR operands

if (a || b || c || d) {}

Every logical leaf counts, regardless of the operator.

3. Mix operators across four operands

if (a && b || c && d) {}

The recursively counted leaves total four.

4. Add parentheses to four operands

if ((a && b) || (c && d)) {}

Parentheses do not reduce the operand count.

5. Exceed a configured maximum

if (isReady && hasAccess && isVisible) {}

This is invalid only with { max: 2 }, where three operands exceed the configured limit.

The rule counts logical-expression leaves recursively and checks only if conditions. A non-logical condition counts as one operand.