@aarongoldenthal/eslint-config-standard

@aarongoldenthal/eslint-config-standard

Summary

Custom ESLint configuration for all projects. Includes flat-config formatted configurations compatible with ESLint v9+ for the following:

Plugin Name	Config name	Rule Prefix
eslint	base-configs	none, core
@eslint-community/eslint-plugin-eslint-comments	eslint-comments-config	comments
eslint-plugin-jest	jest-config	jest
eslint-plugin-jsdoc	jsdoc-config	jsdoc
eslint-plugin-n	node-config	node
eslint-plugin-playwright	playwright-config	playwright
eslint-plugin-promise	promise-config	promise
eslint-plugin-unicorn	unicorn-configs, esm-config	unicorn
eslint-plugin-vitest	vitest-config	vitest

As flat configs, the package defines all required plugins/configurations as dependencies. Since flat config allows flexibility in the rule prefixes (that is, they don't have to match the plugin name), the rules prefixes are adapted in some cases to be more intuitive or readable. Since they may be combined, and flat config doesn't allow nested arrays of rules, file names that are singular export a single config object (for example jsdoc-config), and file names that are plural export an array of config objects (for example base-configs).

The core prefix has only one rule, core/complexity, that has a higher threshold. This provides a secondary check for cases where the lower threshold in the complexity rule is disabled, which otherwise allows unbounded complexity. Since re-use of core rules is an experimental capability, this must be enabled with environment variable ENABLE_ESLINT_CORE_RULE_DUPLICATES=true.

Most rule configurations are applicable to files matching '**/*.{js,mjs,cjs}'. The following configurations are exceptions and are applicable to files as noted:

• base-configs sets sourceType to commonjs for *.js/*.cjs files and module for *.mjs files.
• base-configs includes a config that disables some rules for test files matching any of the following test patterns (for example max-lines, max-lines-per-function).
• jest-config applies rules to files matching '**/__tests__/**/*.{js,mjs,cjs}' or '**/?(*.)+(spec|test).{js,mjs,cjs}'.
• vitest-config applies rules to files matching '**/__tests__/**/*.{js,mjs}' or '**/?(*.)+(spec|test).{js,mjs}'.
• playwright-config: applies rules to files matching '**/*.pwtest.{js,mjs,cjs}', which differentiates them from Jest/Vitest test files.
• unicorn-configs includes a config that disables some rules for test files (matching any of the following test patterns), and applies some ESM-specific rules only applicable to *.mjs files.

With ESLint v9 the majority of formatting rules are deprecated and removed from base-configs, but the eslint-config-prettier package is included and can be added to the config if prettier is also being used to ensure it takes priority for formatting.

There is also an esm-config included for projects using ES modules instead of CommonJS modules. This config sets sourceType to module for *.js files and includes unicorn-config ESM-specific rules.

Usage

This module is now pure ESM, so must be called from an ESM file, either eslint.config.js (if the project is ESM) or eslint.config.mjs (if the project is CJS).

There is a recommended configuration for CJS with all plugin configurations enabled except vitest-config (it does include jest-config, and applies ESM-specific rules to *.mjs files). To configure eslint.config.mjs with this configuration:

import { defineConfig, globalIgnores } from 'eslint/config';
import recommendedConfig from '@aarongoldenthal/eslint-config-standard/recommended';

export default defineConfig([
  recommendedConfig,
  globalIgnores(['.vscode/**', 'archive/**', 'node_modules/**', 'coverage/**'])
]);

Note the optional ignores config that can be added last to ignore certain directories.

There is also a recommended-esm configuration that's the same as the recommended config, but includes the vitest-config instead of the jest-config, and also the esm-config (applicable to *.js files). It can be configured with:

import { defineConfig, globalIgnores } from 'eslint/config';
import recommendedConfig from '@aarongoldenthal/eslint-config-standard/recommended-esm';

export default defineConfig([
  recommendedConfig,
  globalIgnores(['.vscode/**', 'archive/**', 'node_modules/**', 'coverage/**'])
]);

To configure eslint.config.js with individual plugins, see the recommended or recommended-esm configurations as examples.

Notes:

• If used, the base-configs should be included after other configurations, except esm-config and prettier, so those settings take precedence.
• The jest-config and vitest-config have the same file applicability, so only one should be used.
• If used, the esm-config should be configured after all functional rules to ensure the overridden settings take precedence.
• If used, the prettier config should be included last to take priority in disabling the applicable rules from all other configurations.