@coderrob/eslint-plugin-zero-tolerance

no-magic-numbers allows arithmetic in named constants, such as const SOMETHING = 10 * 100;.

Behavioral safety contracts document positive and negative inputs, parameter boundaries, state isolation, and cases that require manual migration.

Rule suites require nonempty valid and invalid fixtures, named should cases, explicit diagnostics, and concrete autofix outputs. All 83 rules also run against shared TypeScript, JSX, optional-access, and Jest-chain parsing fixtures. See the contributor guide for validation requirements.

Strict, opinionated ESLint plugin for TypeScript that enforces type safety, code quality, testing standards, and maintainable patterns — with zero exceptions.

Features

• 83 custom ESLint rules across eight categories: type safety, code quality, testing, imports, error handling, bug prevention, naming conventions, and documentation
• Two presets — recommended generally uses warning severity for gradual adoption, while strict generally uses error severity; strict-only and opt-in exceptions are identified below
• ESLint 8.57+, 9.x, and 10.x — flat config and legacy .eslintrc both supported
• 99%+ test coverage — every rule is thoroughly tested with both valid and invalid cases
• Built with @typescript-eslint/utils for full TypeScript AST support

Requirements

• Node.js
  • 18.18.0+ when using ESLint 8.57.0+ or 9.x
  • 20.19.0+, 22.13.0+, or 24.0.0+ when using ESLint 10.x
  • CI-tested LTS releases: 18.20.8, 20.20.2, 22.23.4, 24.22.2, and 26.13.0
• ESLint 8.57.0+, 9.x, or 10.x
  • CI-tested major releases: 8.57.1, 9.39.5, and 10.14.0
• @typescript-eslint/parser 8.x
• TypeScript 5.x

Installation

npm install --save-dev @coderrob/eslint-plugin-zero-tolerance @typescript-eslint/parser

Quick Start

ESLint 9+ (Flat Config)

// eslint.config.js
import zeroTolerance from '@coderrob/eslint-plugin-zero-tolerance';

export default [zeroTolerance.configs.recommended];

ESLint 8.x (Legacy Config)

// .eslintrc.js
module.exports = {
  plugins: ['@coderrob/zero-tolerance'],
  extends: ['plugin:@coderrob/zero-tolerance/legacy-recommended'],
};

Legacy ESLint resolves the scoped package through the @coderrob/zero-tolerance shorthand, so manually selected legacy rule IDs use @coderrob/zero-tolerance/<rule-name>. Flat configs continue to use the zero-tolerance namespace shown below.

Custom Rule Selection

// eslint.config.js
import zeroTolerance from '@coderrob/eslint-plugin-zero-tolerance';

export default [
  {
    plugins: {
      'zero-tolerance': zeroTolerance,
    },
    rules: {
      'zero-tolerance/require-interface-prefix': 'error',
      'zero-tolerance/no-throw-literal': 'error',
      'zero-tolerance/max-function-lines': ['warn', { max: 40 }],
    },
  },
];

Presets

Preset severities describe the default for enabled rules. prefer-result-return is strict-only, while require-bdd-spec, require-jsdoc-anonymous-functions, no-fetch-in-tests, no-parent-internal-access, and no-restricted-imports-in-tests remain opt-in in both presets. See the full rule documentation for each rule's preset status.

Rules

Naming Conventions

Documentation

Testing

Type Safety

Code Quality

Error Handling

Imports

no-parent-internal-access remains opt-in and only matches the first concrete directory reached after .. traversal, such as ../src/foo.

Bug Prevention

Documentation

Full rule documentation with examples is available at:

https://coderrob.github.io/eslint-config-zero-tolerance/

Choose checks

Use the rule reference to choose checks and review examples, options, and limits. Enable require-error-cause individually to preserve original exceptions.

For promise handling, unsafe types, callback returns, and branching limits, see additional code-quality checks.

License

Apache 2.0 Copyright Robert Lindley