eslint-config-functype

Curated ESLint flat config for functional TypeScript with functype. Composes rules from typescript-eslint, prettier, and simple-import-sort into opinionated recommended and strict presets.

Install

npm install -D eslint-config-functype eslint @typescript-eslint/eslint-plugin @typescript-eslint/parser eslint-plugin-prettier prettier eslint-plugin-simple-import-sort

Usage

// eslint.config.mjs
import recommended from "eslint-config-functype/recommended"
import testOverrides from "eslint-config-functype/test-overrides"

export default [recommended, testOverrides]

Strict mode

import strict from "eslint-config-functype/strict"
import testOverrides from "eslint-config-functype/test-overrides"

export default [strict, testOverrides]

Configs

recommended

• prefer-const, no-var, no-throw-literal
• @typescript-eslint/consistent-type-imports, no-explicit-any, no-floating-promises, await-thenable
• @typescript-eslint/strict-boolean-expressions (warn, relaxed for functional patterns)
• Prettier formatting and import sorting

strict

Everything in recommended plus:

• @typescript-eslint/explicit-function-return-type (error)
• @typescript-eslint/no-non-null-assertion (error)
• @typescript-eslint/strict-boolean-expressions (error, default strict)

test-overrides

Extension point for test files (*.test.ts, *.spec.ts, test/**, tests/**, __tests__/**).

Pairing with eslint-plugin-functype

For functype-specific rules (prefer-option, prefer-either, prefer-fold, etc.):

npm install -D eslint-plugin-functype

import recommended from "eslint-config-functype/recommended"
import functype from "eslint-plugin-functype"

export default [recommended, functype.configs.recommended]

CLI

npx functype-list-rules              # list all configured rules
npx functype-list-rules --verbose    # with rule details
npx functype-list-rules --check-deps # verify peer dependencies

License

MIT