@buildkitgg/oxlint-plugin-anti-slop

anti-slop by Dillon Mulroy, published to npm. Upstream is meant to be copied into each project and has no npm package, so this package is that copy at a pinned commit, without its Effect rules.

anti-slop is an Oxlint plugin that rejects patterns that make TypeScript harder to trust, such as unchecked type assertions, unknown passed around instead of decoded, and conditional empty spreads. It works on its own, without Buildkit's other lint rules.

pnpm add -D @buildkitgg/oxlint-plugin-anti-slop

Oxlint 1.89 or later is required. Vite+ 1.4 includes it.

Recommended rule set

@buildkitgg/oxlint-plugin-anti-slop/recommended registers the plugin and turns on every rule below as an error. With Vite+, extend it from the lint block of vite.config.ts:

import antiSlop from "@buildkitgg/oxlint-plugin-anti-slop/recommended"
import { defineConfig } from "vite-plus"

export default defineConfig({
  lint: { extends: [antiSlop] }
})

With Oxlint on its own, extend it from oxlint.config.ts:

import antiSlop from "@buildkitgg/oxlint-plugin-anti-slop/recommended"
import { defineConfig } from "oxlint"

export default defineConfig({
  extends: [antiSlop]
})

The rule set needs a TypeScript config rather than .oxlintrc.json, because .oxlintrc.json can only extend files by path and the plugin is located at runtime.

To change a rule, set it after extends. Later settings win:

export default defineConfig({
  extends: [antiSlop],
  rules: {
    "anti-slop/require-readable-spacing": "off",
    "anti-slop/no-runtime-typeof": ["error", { allowInTypeGuards: true }]
  },
  overrides: [{ files: ["**/*.test.ts"], rules: { "anti-slop/no-module-mocking": "off" } }]
})

Choosing rules yourself

Register the plugin by package name under jsPlugins and turn on only the rules you want. This works from .oxlintrc.json too:

{
  "jsPlugins": [{ "name": "anti-slop", "specifier": "@buildkitgg/oxlint-plugin-anti-slop" }],
  "rules": {
    "anti-slop/no-array-filter-map": "error",
    "anti-slop/no-chained-type-assertions": "error"
  }
}

Rules

| Rule | What it reports | | ----------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------ | | anti-slop/no-array-filter-map | A filter followed by a map. Use one transformation or lazy iterator helpers | | anti-slop/no-reduce-accumulator-copy | Reducers that copy their growing accumulator with Object.assign, Array.from or array copy methods | | anti-slop/no-chained-type-assertions | Chained as or angle-bracket assertions, such as value as unknown as User | | anti-slop/no-conditional-empty-object-spread | ...(condition ? { field } : {}) and similar spreads used to leave fields out | | anti-slop/no-known-value-widening | Known values passed into broad or anonymous types that throw away what was known about them | | anti-slop/no-module-mocking | vi.mock and jest.mock. Replace dependencies through real interfaces instead | | anti-slop/no-object-parameters | Parameters typed with the broad object type. Accept a named type, and parse external input at its boundary | | anti-slop/no-reflect-apply | Reflect.apply. Call typed functions directly | | anti-slop/no-reflect-get | Reflect.get. Use typed property access, or parse dynamic input into a domain type | | anti-slop/no-runtime-typeof | Runtime typeof checks. Decode external values at their I/O boundary. allowInTypeGuards permits them inside type guards | | anti-slop/no-unsafe-dictionary-type | Dictionary types whose values are unknown, any, object or {} | | anti-slop/no-shape-in-symbol-names | Names containing "shape" | | anti-slop/no-unknown-parameters | Parameters typed unknown, other than cause and type guard subjects | | anti-slop/no-unknown-returns | Functions declared to return unknown or Promise<unknown> | | anti-slop/no-unknown-type-aliases | Type aliases that resolve to unknown | | anti-slop/no-widen-then-assert | A known value widened to a broader type and then asserted back to a narrower one | | anti-slop/require-readable-spacing | Missing blank lines between declarations and groups of statements. Fixable with oxlint --fix | | anti-slop/require-safety-comment-for-type-assertion | Type assertions without a nearby SAFETY: comment explaining why they hold. as const is exempt. markers changes the comment tag | | oxc/no-accumulating-spread | Spreading an accumulator inside reduce or a loop, which copies it on every pass |

oxc/no-accumulating-spread is a built-in Oxlint rule that the recommended rule set turns on alongside the plugin's.

Upstream is MIT licensed, and its license ships with this package. See vendored anti-slop for how the copy is updated.

Oxlint JS plugins are in alpha and outside semver, so a new Oxlint release may need a matching release of this package.