preact-signals-eslint-plugin

name	preact-signals-eslint-plugin
description	Use when configuring, extending, or debugging @preact/eslint-plugin-signals rules for Preact Signals misuse, including conditional value reads, signal truthiness, signal writes in computed, values after await, and signal creation in component bodies.

Preact Signals ESLint Plugin

Core Approach

Use lint rules for common static signal misuse that issue history shows humans and agents repeat. The plugin supports projects using @preact/signals-core, @preact/signals, @preact/signals-react, and @preact/signals-react/runtime.

Configuration

Oxlint:

{
  "jsPlugins": ["@preact/eslint-plugin-signals"],
  "rules": {
    "@preact/signals/no-signal-write-in-computed": "error",
    "@preact/signals/no-value-after-await": "error",
    "@preact/signals/no-signal-truthiness": "warn",
    "@preact/signals/no-signal-in-component-body": "error",
    "@preact/signals/no-conditional-value-read": "error"
  }
}

ESLint flat config:

import signals from "@preact/eslint-plugin-signals";
import tsParser from "@typescript-eslint/parser";

export default [
  {
    plugins: { signals },
    languageOptions: {
      ecmaVersion: 2022,
      sourceType: "module",
      parser: tsParser,
      parserOptions: {
        ecmaFeatures: { jsx: true },
        project: true,
        tsconfigRootDir: import.meta.dirname
      }
    },
    rules: {
      "signals/no-signal-write-in-computed": "error",
      "signals/no-value-after-await": "error",
      "signals/no-signal-truthiness": "warn",
      "signals/no-signal-in-component-body": "error",
      "signals/no-conditional-value-read": "error"
    }
  }
];

Rule Intent

Rule	Catches
no-signal-write-in-computed	Side effects inside computed() or useComputed()
no-value-after-await	.value reads after await that are not tracked
no-signal-truthiness	if (signal) and similar always-truthy checks
no-signal-in-component-body	signal(), computed(), effect() created on every render
no-conditional-value-read	.value reads hidden behind non-reactive guards

Common Limitations

• Cross-function data flow is not fully traced.
• Dynamic object aliases may not be detected without TypeScript type information.
• Oxlint currently has less type-aware information than ESLint with @typescript-eslint/parser and project: true.

References

• Package docs: node_modules/@preact/eslint-plugin-signals/README.md
• Online: https://github.com/preactjs/signals/blob/main/packages/eslint-plugin-signals/README.md