@ariestools/eslint-config-flat

ESLint 9/10 flat config tiers for Aries Tools TypeScript packages

Install

Requires Node.js ≥ 22. pnpm is fully supported; npm / yarn / bun are experimental.

pnpm add -D @ariestools/eslint-config-flat

Peer: eslint ^10.3 and eslint-import-resolver-typescript ^4.4.

Usage

import { recommendedConfig } from '@ariestools/eslint-config-flat'

export default [
  ...recommendedConfig({ tier: 3, isTypeChecked: true }),
]

recommendedConfig accepts:

| Option | Default | Description | |--------|---------|-------------| | tier | 3 | Preset strictness level (0–4) | | isTypeChecked | true | Enable TypeScript type-checked rules |

When isTypeChecked is false, all rules that require parser type information are disabled across every tier, and a safety-net gate turns off any type-checked preset rules that would otherwise remain active.

Tiers

Each tier is a superset of the previous tier.

| Tier | Category | Description | |------|----------|-------------| | 0 | Correctness | Type safety, bug prevention, import restrictions, markdown | | 1 | Consistency | Tier 0 + formatting, member ordering, complexity limits | | 2 | Best practices | Tier 1 + unicorn, import validation, workspace rules | | 3 | Opinionated (default) | Tier 2 + unicorn opinionated rules and optional rules promoted to errors | | 4 | Experimental | Tier 3 + newer unicorn warnings (canary; may change on a minor) |

Rule tier assignments live in RULE_CATALOG (exported from this package). Named exports such as configTier3OpinionatedTypeChecked remain available but are deprecated. Prefer recommendedConfig({ tier: 3, isTypeChecked: true }).

Rules introduced only at tier 3 or 4 default to warnings. Use xy lint --strict (or XY_STRICT=1) to treat warnings as errors in CI.

Extending with custom rules

import { recommendedConfig } from '@ariestools/eslint-config-flat'

export default [
  ...recommendedConfig({ tier: 3, isTypeChecked: true }),
  {
    rules: {
      // your overrides
    },
  },
]

Individual configs

import {
  importConfig,
  rulesConfig,
  typescriptConfig,
  unicornConfig,
} from '@ariestools/eslint-config-flat'

JSON/markdown helpers: jsonConfig, docsConfig. There is no SonarJS config in this package (xy sonar is a separate, quarantined CLI command).

What's included

• TypeScript strict linting via @typescript-eslint
• Import sorting and validation via eslint-plugin-import-x
• Best practices via eslint-plugin-unicorn
• Monorepo workspace rules via eslint-plugin-workspaces
• Markdown linting via @eslint/markdown
• Stylistic formatting (no semicolons, single quotes, trailing commas, 2-space indent)

For React projects, use @ariestools/eslint-config-react-flat instead.

Rule ownership

Some plugins cover similar territory. This config assigns a single canonical owner per concern and disables overlapping rules. See RULE_OWNERSHIP_GROUPS and assertNoRuleOwnershipConflicts.

When upgrading ESLint plugins, run tests in this package — spec/plugin-rules.spec.ts snapshots each plugin's rule list and fails when new rules appear.

License

LGPL-3.0-only. See LICENSE (LGPLv3) and COPYING (GPLv3, incorporated by LGPL-3).

Credits

Made with 🔥 and ❄️ by Aries Tools