no-network-fast-result

Disallows FastResult in contracts passed to Networking.createFunction from @flamework/networking.

Rule details Problem

FastResult is a LuaTuple, which cannot cross a Flamework network boundary. The rule resolves imported and aliased FastResult types, including nested response types such as Promise<FastResult>.

It only checks RPC contracts. Local helpers may still return FastResult normally.

No automatic fix

Choose a serializable response shape for each endpoint, such as an object with success and message properties.

Examples

Incorrect

import { Networking } from "@flamework/networking";

interface ClientToServer {
  warp: { toCFrame: () => FastResult };
}

Networking.createFunction<ClientToServer, undefined>();

Correct

import { Networking } from "@flamework/networking";

interface ClientToServer {
  warp: { toCFrame: () => { success: boolean; message?: string } };
}

Networking.createFunction<ClientToServer, undefined>();

Options

Option	Type	Default	Description
checkParameters	boolean	false	Also report FastResult in RPC parameter types.

export default [
  {
    rules: {
      "cease-nonsense/no-network-fast-result": ["error", { checkParameters: true }],
    },
  },
];