@pyreon/lint

Pyreon-specific linter powered by oxc-parser — 51 rules across 11 categories for signals, JSX, SSR, performance, and architecture.

Installation

bun add @pyreon/lint

Usage

CLI

# Lint current directory with recommended preset
pyreon-lint

# Lint specific paths
pyreon-lint src/ components/

# Use a preset
pyreon-lint --preset strict src/

# Auto-fix fixable issues
pyreon-lint --fix src/

# JSON output
pyreon-lint --format json src/

# Only show errors (skip warnings and info)
pyreon-lint --quiet src/

# Override a rule
pyreon-lint --rule pyreon/no-map-in-jsx=off src/

# List all rules
pyreon-lint --list

Programmatic API

import { lint, listRules, lintFile, applyFixes } from '@pyreon/lint'

// Lint files
const result = lint({
  paths: ['src/'],
  preset: 'recommended',
  fix: false,
  quiet: false,
})

console.log(`${result.totalErrors} errors, ${result.totalWarnings} warnings`)

// List all rules
for (const rule of listRules()) {
  console.log(`${rule.id} (${rule.severity}): ${rule.description}`)
}

// Lint a single source string
import { getPreset } from '@pyreon/lint'
import { allRules } from '@pyreon/lint/rules'

const fileResult = lintFile('app.tsx', source, allRules, getPreset('recommended'))

Rules (51)

Reactivity (8)

| Rule | Severity | Fixable | Description | | ------------------------------ | -------- | ------- | ------------------------------------------------- | | pyreon/no-bare-signal-in-jsx | error | Yes | Flags {count()} in JSX text — wrap in () => | | pyreon/no-signal-in-loop | error | No | Flags signal()/computed() inside loops | | pyreon/no-nested-effect | warn | No | Flags effect() inside effect() | | pyreon/no-peek-in-tracked | error | No | Flags .peek() inside effect/computed | | pyreon/no-unbatched-updates | warn | No | Flags 3+ .set() calls without batch() | | pyreon/prefer-computed | warn | No | Suggests computed() for effect with single .set() | | pyreon/no-effect-assignment | warn | No | Flags effect with single .update() | | pyreon/no-signal-leak | warn | No | Reports unused signal declarations |

JSX (11)

| Rule | Severity | Fixable | Description | | ------------------------------- | -------- | ------- | ------------------------------------------ | | pyreon/no-map-in-jsx | warn | No | Prefer <For> over .map() in JSX | | pyreon/use-by-not-key | error | Yes | Use by not key on <For> | | pyreon/no-classname | error | Yes | Use class not className | | pyreon/no-htmlfor | error | Yes | Use for not htmlFor | | pyreon/no-onchange | warn | Yes | Prefer onInput over onChange on inputs | | pyreon/no-ternary-conditional | warn | No | Prefer <Show> over ternary with JSX | | pyreon/no-and-conditional | warn | No | Prefer <Show> over && with JSX | | pyreon/no-index-as-by | warn | No | Don't use index as by prop | | pyreon/no-missing-for-by | warn | No | <For> should have by prop | | pyreon/no-props-destructure | error | No | Don't destructure component props | | pyreon/no-children-access | info | No | Direct props.children access in renderers |

Lifecycle (4)

| Rule | Severity | Fixable | Description | | --------------------------- | -------- | ------- | ---------------------------------------- | | pyreon/no-missing-cleanup | warn | No | onMount with timers needs cleanup return | | pyreon/no-mount-in-effect | warn | No | Don't call onMount inside effect | | pyreon/no-effect-in-mount | info | No | effect() inside onMount is unusual | | pyreon/no-dom-in-setup | warn | No | DOM queries outside onMount/effect |

Performance (4)

| Rule | Severity | Fixable | Description | | --------------------------------- | -------- | ------- | ------------------------------------------ | | pyreon/no-large-for-without-by | error | No | <For> must have by for reconciliation | | pyreon/no-effect-in-for | warn | No | Don't create effects inside <For> | | pyreon/no-eager-import | info | No | Lazy-load heavy packages | | pyreon/prefer-show-over-display | info | No | Use <Show> instead of CSS display toggle |

SSR (3)

| Rule | Severity | Fixable | Description | | ------------------------------- | -------- | ------- | ----------------------------------- | | pyreon/no-window-in-ssr | error | No | Browser globals outside safe scopes | | pyreon/no-mismatch-risk | warn | No | Non-deterministic calls in JSX | | pyreon/prefer-request-context | warn | No | Module-level state in server files |

Architecture (5)

| Rule | Severity | Fixable | Description | | -------------------------------- | -------- | ------- | ---------------------------------- | | pyreon/no-circular-import | error | No | Enforce package layer order | | pyreon/no-deep-import | warn | No | No @pyreon/*/src/ imports | | pyreon/no-cross-layer-import | error | No | Core can't import ui-system | | pyreon/dev-guard-warnings | error | No | console.warn/error needs __DEV__ | | pyreon/no-error-without-prefix | warn | Yes | Errors need [Pyreon] prefix |

Store (3)

| Rule | Severity | Fixable | Description | | ---------------------------------- | -------- | ------- | -------------------------------- | | pyreon/no-store-outside-provider | warn | No | Store hooks need provider in SSR | | pyreon/no-mutate-store-state | warn | No | Use actions, not direct .set() | | pyreon/no-duplicate-store-id | error | No | Unique defineStore() IDs |

Form (3)

| Rule | Severity | Fixable | Description | | ------------------------------------- | -------- | ------- | ----------------------------------- | | pyreon/no-unregistered-field | warn | No | useField() without register() | | pyreon/no-submit-without-validation | warn | No | useForm onSubmit without validators | | pyreon/prefer-field-array | info | No | signal([]) in form files |

Styling (4)

| Rule | Severity | Fixable | Description | | ---------------------------------- | -------- | ------- | ------------------------------ | | pyreon/no-inline-style-object | warn | No | Inline style objects in JSX | | pyreon/no-dynamic-styled | warn | No | styled() inside functions | | pyreon/prefer-cx | info | No | Use cx() for class composition | | pyreon/no-theme-outside-provider | warn | No | useTheme() without provider |

Hooks (3)

| Rule | Severity | Fixable | Description | | -------------------------------- | -------- | ------- | ---------------------- | | pyreon/no-raw-addeventlistener | info | No | Use useEventListener() | | pyreon/no-raw-setinterval | info | No | Wrap timers in onMount | | pyreon/no-raw-localstorage | info | No | Use useStorage() |

Accessibility (3)

| Rule | Severity | Fixable | Description | | --------------------- | -------- | ------- | ------------------------------------ | | pyreon/toast-a11y | warn | No | Toast components need role/aria-live | | pyreon/dialog-a11y | warn | No | <dialog> needs aria-label | | pyreon/overlay-a11y | warn | No | <Overlay> needs role/aria-label |

Presets

| Preset | Description | | ------------- | ------------------------------------ | | recommended | All rules at default severity | | strict | All warnings promoted to errors | | app | Recommended minus library-only rules | | lib | Strict plus architecture checks |

Rule Options

Every rule entry in your config accepts either a bare severity or a [severity, options] tuple — ESLint-style. The tuple form lets you pass per-rule options without a bespoke API per rule.

// .pyreonlintrc.json
{
  "$schema": "./node_modules/@pyreon/lint/schema/pyreonlintrc.schema.json",
  "preset": "recommended",
  "rules": {
    "pyreon/no-window-in-ssr": "error",
    "pyreon/no-raw-addeventlistener": [
      "info",
      { "exemptPaths": ["packages/core/runtime-dom/", "src/foundation/"] }
    ]
  }
}

The $schema reference enables IDE autocomplete + validation when editing the config — VSCode, IntelliJ, Zed, and the LSP all pick it up automatically.

Convention: exemptPaths. Rules that support path-based exemption read options.exemptPaths: string[]. Each entry is a substring match against the file path. Missing or empty → no exemptions. Rules currently supporting exemptPaths:

• pyreon/no-window-in-ssr — packages that are DOM-only (no SSR scenario)
• pyreon/no-raw-addeventlistener — packages implementing useEventListener / event delegation
• pyreon/no-raw-setinterval — packages implementing useInterval / useTimeout
• pyreon/no-process-dev-gate — server-only directories (Node environments)
• pyreon/dev-guard-warnings — server-only + demo / example directories
• pyreon/require-browser-smoke-test — packages explicitly opted out (e.g. experimental); also accepts additionalPackages: string[] to extend the browser-categorized list

Validation. Each rule declares its option shape in meta.schema. The runner validates user config once per (rule, options) pair:

• Unknown option keys → warning surfaced on LintResult.configDiagnostics (and stderr), rule stays enabled
• Wrong-typed values → error surfaced on LintResult.configDiagnostics (and stderr), rule disabled for that run
• Rules without a schema accept any options (no validation)

Programmatic consumers (CI dashboards, LSP, JSON reporters) read result.configDiagnostics alongside result.files[].diagnostics.

CLI option overrides. --rule-options id='{json}' passes JSON-encoded options to a specific rule from the command line — useful for one-off lint runs without editing the config file:

pyreon-lint --rule-options 'pyreon/no-window-in-ssr={"exemptPaths":["src/foundation/"]}' src/

Custom Rules

import type { Rule } from '@pyreon/lint'

const myRule: Rule = {
  meta: {
    id: 'custom/my-rule',
    category: 'reactivity',
    description: 'My custom rule',
    severity: 'warn',
    fixable: false,
    // Optional: declare options shape. If present, the runner validates
    // user config against it. Supported types:
    //   'string' | 'string[]' | 'number' | 'boolean'
    schema: { exemptPaths: 'string[]' },
  },
  create(context) {
    // Read options from user config (tuple form).
    const options = context.getOptions()
    // Or use the `isPathExempt` helper for the `exemptPaths` convention:
    //   import { isPathExempt } from '@pyreon/lint'
    //   if (isPathExempt(context)) return {}

    return {
      CallExpression(node) {
        context.report({
          message: 'Something is wrong',
          span: { start: node.start, end: node.end },
        })
      },
    }
  },
}

License

MIT