Prefer Membership Filter In Jecs

ErrorAuto-fixableRoblox

small-rules/prefer-membership-filter-in-jecs

Move discarded Jecs query component values into a membership-only with filter.

Rationale

query() returns component values in argument order. When a loop does not consume one of those values, putting the component in with() makes its membership-only role explicit. This is a clarity rule, not a generated-code performance claim.

The rule handles direct query chains only. It leaves stored queries and rest bindings alone, and it withholds a fix when moving a component expression could change evaluation order or side effects.

Diagnostic Messages

preferMembershipFilter

Move components whose values are not consumed from query() to with().

Configuration

This rule does not accept options.

.oxlintrc.json

{
  "jsPlugins": [
    "@pobammer-ts/small-rules"
  ],
  "rules": {
    "small-rules/prefer-membership-filter-in-jecs": "error"
  }
}

oxlint.config.ts

import { defineConfig } from "oxlint";

export default defineConfig({
  jsPlugins: ["@pobammer-ts/small-rules"],
  rules: {
    "small-rules/prefer-membership-filter-in-jecs": "error",
  },
});

Examples

discarded queried component value

import { world } from "@rbxts/jecs";
const gameWorld = world();
for (const [entity, visual, transform] of gameWorld.query(Visual, Transform).with(User)) {
  render(entity, visual);
}

After auto-fix

import { world } from "@rbxts/jecs";
const gameWorld = world();
for (const [entity, visual] of gameWorld.query(Visual).with(Transform, User)) {
  render(entity, visual);
}

membership-only components in with

import { world } from "@rbxts/jecs";
const gameWorld = world();
for (const [entity, visual] of gameWorld.query(Visual).with(Transform, User)) render(entity, visual);