eslint-plugin-ts-data-forge

ESLint rules that steer TypeScript code toward ts-data-forge idioms — e.g. preferring Arr.isNonEmpty(xs) over xs.length > 0, isRecord(x) && hasKey(x, k) over Object.hasOwn(x, k), or Num.safeParseInt over parseInt. Every rule is auto-fixable.

Installation

npm install --save-dev eslint-plugin-ts-data-forge

Requires ESLint 9+ (flat config) and TypeScript. Some rules are type-aware and need a configured TypeScript project.

Usage (flat config)

The plugin ships a recommended config preset that registers the plugin and turns on every rule at error:

// eslint.config.mts
import { eslintPluginTsDataForge } from 'eslint-plugin-ts-data-forge';

export default [eslintPluginTsDataForge.configs.recommended];

Since the preset is a plain flat-config object, individual rules can be adjusted by a later config entry:

// eslint.config.mts
import {
    eslintPluginTsDataForge,
    type EslintTsDataForgeRules,
} from 'eslint-plugin-ts-data-forge';

export default [
    eslintPluginTsDataForge.configs.recommended,
    {
        rules: {
            'ts-data-forge/prefer-range-for-loop': 'off',
        } satisfies Partial<EslintTsDataForgeRules>,
    },
];

Or register the plugin yourself and pick the rules one by one:

// eslint.config.mts
import {
    eslintPluginTsDataForge,
    type EslintTsDataForgeRules,
} from 'eslint-plugin-ts-data-forge';

export default [
    {
        plugins: { 'ts-data-forge': eslintPluginTsDataForge },
        rules: {
            'ts-data-forge/prefer-canonical-length-guard': 'error',
            'ts-data-forge/prefer-canonical-length-cast': 'error',
            'ts-data-forge/prefer-is-record-and-has-key': 'error',
            // ...enable the rules you want
        } satisfies Partial<EslintTsDataForgeRules>,
    },
];

Rules

| Rule | Description | | -------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | prefer-canonical-array-slicing | Unify non-mutating array add/remove patterns into Arr.tail/skip/take/etc. | | prefer-canonical-length-guard | Normalize array-length checks to the canonical Arr guard (xs.length > 0 → Arr.isNonEmpty, Arr.isFixedLengthArray(0, xs) → Arr.isEmpty, Arr.isFixedLengthTuple(0, xs) → Arr.isEmptyTuple, …). | | prefer-canonical-length-cast | Normalize a degenerate Arr length cast to the canonical one (Arr.asMinLengthArray(1, xs) → Arr.asNonEmptyArray(xs), Arr.asBoundedLengthArray(n, n, xs) → Arr.asFixedLengthArray(n, xs), …). | | prefer-arr-is-array | Replace Array.isArray with Arr.isArray. | | prefer-arr-sum | Replace xs.reduce((a, b) => a + b, 0) with Arr.sum(xs) / Arr.sumBy(xs, fn). | | prefer-as-int | Replace branded-number assertions (x as Int) with asInt(x)-style casts. | | prefer-is-non-null-object | Replace typeof u === 'object' && u !== null with isNonNullObject(u). | | prefer-range-for-loop | Replace C-style for loops with for (const i of range(begin, end)). | | prefer-is-record-and-has-key | Replace Object.hasOwn(obj, key) / key in obj with isRecord(obj) && hasKey(…). | | prefer-num-safe-parse-int | Replace parseInt(x, 10) with Result.unwrapOkOr(Num.safeParseInt(x), NaN). | | prefer-num-safe-parse-float | Replace parseFloat(x) / Number(x) with Num.safeParseFloat-based parsing. | | no-unnecessary-type-guard | Flag ts-data-forge type-guard calls that do no narrowing (type-aware). | | prefer-comparison-over-nullish-guard | Prefer direct === null / !== undefined over isNull / isNotUndefined calls. |

License

Apache-2.0