Function resolveRequestedPort

packages/cli/src/commands/ui.ts:395–414

(
  optsPort: string | undefined,
  envPort: string | undefined,
)

}

function resolveRequestedPort(
  optsPort: string | undefined,
  envPort: string | undefined,
): ResolvedRequestedPort {
  if (optsPort !== undefined) {
    const parsed = Number.parseInt(optsPort, 10);
    if (Number.isNaN(parsed) || parsed < 0 || parsed > 65535) {
      throw new Error(`Invalid --port value '${optsPort}'`);
    }
    return { port: parsed, fallbackToKernel: false };
  }
  if (envPort !== undefined && envPort !== '') {
    const parsed = Number.parseInt(envPort, 10);
    if (Number.isNaN(parsed) || parsed < 0 || parsed > 65535) {
      throw new Error(`Invalid PORT env value '${envPort}'`);
    }
    return { port: parsed, fallbackToKernel: false };
  }
  return { port: DEFAULT_UI_PORT, fallbackToKernel: true };
}

type UiCollisionResult =
  | { mode: 'already-running'; port: number }