anti-slop

Opinionated Oxlint rules that reject low-evidence and low-signal TypeScript and JavaScript patterns.

This project is meant to be vendored, not treated as a fixed npm dependency. Copy the rules into your repository, read them, and change them to match your team's standards. The bundled agent skill handles the initial copy and configuration; after that, the vendored files are yours to maintain and make your own.

Install with an agent skill

npx skills add dmmulroy/anti-slop --skill install-anti-slop

Then ask your coding agent to install or configure anti-slop in the current repository. The skill copies the plugin, installs current Oxlint dependencies, merges the plugin into the existing lint configuration, enables every rule, and validates the result.

To inspect available skills first:

npx skills add dmmulroy/anti-slop --list

Manual local installation

Copy src/ into the target repository, for example at tools/oxlint/anti-slop/, and install matching current versions of oxlint and @oxlint/plugins.

Register the copied entry point in oxlint.config.ts:

import { defineConfig } from "oxlint";

export default defineConfig({
  jsPlugins: [
    { name: "anti-slop", specifier: "./tools/oxlint/anti-slop/index.ts" },
  ],
  rules: {
    "anti-slop/no-chained-type-assertions": "error",
    "anti-slop/no-conditional-empty-object-spread": "error",
    "anti-slop/no-known-value-widening": "error",
    "anti-slop/no-object-parameters": "error",
    "anti-slop/no-runtime-typeof": "error",
    "anti-slop/no-shape-in-symbol-names": "error",
    "anti-slop/no-unknown-parameters": "error",
    "anti-slop/no-unknown-type-aliases": "error",
    "anti-slop/no-unsafe-dictionary-type": "error",
    "anti-slop/no-widen-then-assert": "error"
  }
});

The same jsPlugins entry and rules work under lint in a Vite+ config.

Rules

• no-chained-type-assertions — rejects nested type assertions that fabricate evidence.
• no-conditional-empty-object-spread — rejects conditional spreads that use {} to omit fields.
• no-known-value-widening — rejects explicit broad target types that discard known value evidence.
• no-object-parameters — rejects the broad object type on function inputs.
• no-runtime-typeof — requires boundary parsing instead of ad hoc typeof narrowing.
• no-shape-in-symbol-names — rejects shape in symbol names.
• no-unknown-parameters — rejects unknown inputs except the explicit cause convention.
• no-unknown-type-aliases — rejects aliases that merely conceal unknown.
• no-unsafe-dictionary-type — rejects dictionary value contracts based on unknown, any, object, {}, and semantic equivalents.
• no-widen-then-assert — rejects local flows that widen known values and later assert them back.

Violation examples

Each snippet below is rejected by the named rule.

no-chained-type-assertions

const user = input as object as User;

no-conditional-empty-object-spread

const options = {
  ...(timeout !== undefined ? { timeout } : {}),
};

no-known-value-widening

const handlers: Record<string, Handler> = {
  start: startHandler,
};

This discards the known start key. Preserve inference or use satisfies Record<string, Handler> instead.

no-object-parameters

function save(value: object) {}

no-runtime-typeof

if (typeof input === "string") {
  useName(input);
}

no-shape-in-symbol-names

interface UserShape {
  id: string;
}

no-unknown-parameters

function handle(input: unknown) {}

no-unknown-type-aliases

type ExternalValue = unknown;

no-unsafe-dictionary-type

type Metadata = Record<string, unknown>;
type OtherMetadata = { [key: string]: object };

no-widen-then-assert

const loaded: User = loadUser();
const stored: unknown = loaded;
const user = stored as User;

Development

pnpm install
pnpm check

src/ is canonical. After changing production source, run pnpm sync:skill-assets; CI checks that the skill's bundled copy remains identical.

License

MIT