eslint-ava-rule-tester

5.0.1 verified Sat Apr 25 auth: no javascript

ESLint RuleTester runner for AVA test framework. Wraps ESLint's RuleTester to produce per-test reports in AVA format. Current stable version 5.0.1, pure ESM, requires Node.js >=18 and ESLint >=8.7.0. Supports all RuleTester features including valid/invalid cases, fix output, and error options. Releases: v5 breaking change to ESM-only; v4 dropped Node <7 and upgraded to ESLint v6; v2 added support for AVA 0.19. Key differentiator: provides granular test results instead of a single pass/fail for the entire rule suite.

Common errors

error Error [ERR_REQUIRE_ESM]: require() of ES Module not supported. ↓

cause Trying to use require() with ESM-only package (v5+).

fix

Switch to import or use dynamic import: const AvaRuleTester = await import('eslint-ava-rule-tester');

error TypeError: Class extends value undefined is not a constructor or null ↓

cause Missing or incompatible peer dependency, typically eslint is not installed or version is too low.

fix

Install eslint >=8.7.0 as a dev dependency.

error Cannot find module 'eslint-ava-rule-tester' ↓

cause Package not installed or not in node_modules.

fix

Run npm install --save-dev eslint-ava-rule-tester

Warnings

breaking v5.0.0 is pure ESM and requires Node.js >=18. CommonJS require() will not work. ↓

fix Use import syntax and ensure Node.js version is >=18. If you must use CJS, upgrade to a dynamic import or pin to v4.x.

breaking v4.0.0 dropped support for Node.js <7 and requires ESLint v6 as peer dependency. ↓

fix Upgrade Node.js to at least v8 and ESLint to v6 or higher.

breaking v2.0.1 requires AVA >=0.19 which enforces at least one assertion per test. ↓

fix Ensure AVA version is at least 0.19.0.

breaking v5.0.0 changed the internal implementation to subclass RuleTester instead of modifying it. This may affect custom extensions. ↓

fix If you were relying on prototype modifications to RuleTester, adapt to use the provided subclass instead.

Install

npm install eslint-ava-rule-tester

yarn add eslint-ava-rule-tester

pnpm add eslint-ava-rule-tester

Imports

default

wrong

const AvaRuleTester = require('eslint-ava-rule-tester');

correct

import AvaRuleTester from 'eslint-ava-rule-tester';

ESM-only since v5; CommonJS require will fail. Use dynamic import or upgrade.

AvaRuleTester

wrong

import { AvaRuleTester } from 'eslint-ava-rule-tester';

correct

import AvaRuleTester from 'eslint-ava-rule-tester';

Default export only; named import not available.

type inference

wrong

import { type AvaRuleTester } from 'eslint-ava-rule-tester';

correct

import type AvaRuleTester from 'eslint-ava-rule-tester';

TypeScript users can use import type for type-only import.

Quickstart

Shows how to create an AvaRuleTester instance, passing the AVA test function and ESLint config, then run valid and invalid test cases.

import test from 'ava';
import AvaRuleTester from 'eslint-ava-rule-tester';
import myRule from '../eslint-rules/my-rule.js';

const ruleTester = new AvaRuleTester(test, {
  languageOptions: {
    ecmaVersion: 2024,
  },
});

ruleTester.run('my-rule', myRule, {
  valid: [
    'valid code',
  ],
  invalid: [
    {
      code: 'invalid code',
      errors: [{ message: 'Error message' }],
    },
  ],
});