biome-plugin-solidjs

Biome GritQL lint rules for SolidJS. Catches common reactivity bugs at lint time.

Rules

| Rule | Description | |------|-------------| | solid-no-destructured-props | Flags destructured props in component parameter lists. Props are reactive getter objects — destructuring severs reactivity. Body-level destructuring (hooks, contexts) is allowed. | | solid-no-array-map-in-jsx | Flags .map() inside JSX expressions. In Solid, .map() runs once and produces static DOM. Use <For> or <Index>. | | solid-no-memo-in-loop | Flags createMemo() inside .map(), .forEach(), and other array method callbacks. | | solid-no-toplevel-effect | Flags createEffect() and createMemo() at module scope, where they have no reactive owner and will leak. | | solid-no-stored-jsx | Flags JSX stored in module-scope variables. Solid JSX compiles to real DOM operations, not virtual DOM descriptors. |

Opt-in rules

These rules are included in the package but not enabled by the manifest. Add them individually if they match your codebase:

| Rule | Description | |------|-------------| | solid-no-object-signal-without-equals | Flags createSignal<Type \| null>() without a custom equals function. Catches auth/session signals where the same entity arrives with different references, but may false-positive on set-once-then-clear patterns. |

Install

npm install -D biome-plugin-solidjs

Setup

Add the plugin to your biome.json or biome.jsonc:

{
  "plugins": ["./node_modules/biome-plugin-solidjs"]
}

To also enable the opt-in rule:

{
  "plugins": [
    "./node_modules/biome-plugin-solidjs",
    "./node_modules/biome-plugin-solidjs/rules/solid-no-object-signal-without-equals.grit"
  ]
}

Requirements

• Biome >= 2.0.0 (GritQL plugin support)

How it works

Each rule is a .grit file using Biome's GritQL engine (engine biome(1.0)) to match AST patterns. The rules use structural heuristics rather than type information:

• Component detection: Functions returning JSX are treated as components (for the destructured props rule). Only parameter-level destructuring is flagged — body-level destructuring from hooks and contexts (const { user } = useAuth()) is allowed.
• Scope detection: ! $node <: within JsArrowFunctionExpression() patterns distinguish module-level code from code inside functions.
• No type inference: These rules can't catch bugs that require knowing TypeScript types (e.g., uncalled signals, direct store mutation). For those, consider eslint-plugin-solid.

What these rules don't cover

Some SolidJS pitfalls require TypeScript type information that GritQL doesn't have access to:

• Signals referenced without () (needs to know what's a signal)
• Direct store mutation (needs to know what's a store proxy)
• Store prop destructuring from custom hooks (needs return type info)

For full type-aware linting, use these rules alongside eslint-plugin-solid.

License

MIT