eslint-config-amex/src/test-config.js

American Express' ESLint config

/*
 * Copyright (c) 2026 American Express Travel Related Services Company, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
 * in compliance with the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License
 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */

import { defineConfig } from "eslint/config";
import globals from "globals";
import eslintPluginJest from "eslint-plugin-jest";
import eslintPluginJestDom from "eslint-plugin-jest-dom";
import eslintPluginN from "eslint-plugin-n";
import baseConfig from "./index.js";
import { JS_FILES_IN_TEST_DIR } from "./constants/index.js";

const amexJsTestConfig = (overrides = {}) => defineConfig([
  // https://github.com/americanexpress/eslint-config-amex/blob/16.x/test.js
  {
    name: "eslint-config-amex/test-config",
    files: overrides.files ?? [JS_FILES_IN_TEST_DIR],
    ...(overrides.ignores ? { ignores: overrides.ignores } : []),
    extends: [baseConfig({ files: overrides.files ?? [JS_FILES_IN_TEST_DIR] })],
    plugins: {
      jest: eslintPluginJest,
      "jest-dom": eslintPluginJestDom,
      n: eslintPluginN,
    },
    languageOptions: {
      globals: {
        ...globals.jest,
      },
    },
    rules: {
      ...eslintPluginJest.configs["flat/recommended"].rules,
      ...eslintPluginJestDom.configs["flat/recommended"].rules,

      // open a PR per rule change

      // the way jest mocking works sometimes requires requiring within scope of each test
      "n/global-require": "warn",
      // skipped tests can lead to false build successes
      "jest/no-disabled-tests": "error",
      // forces you to remove .only from tests by raising error whenever you are using that feature.
      "jest/no-focused-tests": "error",
      // disallows having tests with identical name
      "jest/no-identical-title": "error",
      // disallows large snapshots (default 50 line threshold)
      "jest/no-large-snapshots": "error",
      // prop spreading is very useful in tests for specs that including variations of the same
      // props repeatedly
      "react/jsx-props-no-spreading": 0,

      ...overrides.rules,
    },
  },
]);

export default amexJsTestConfig;