在这个生成的转账边界处理不可信 JSON 前，对它进行审查。
解析正安全整数账户 ID 和分值，拒绝向自己转账，验证付款账户权限，并准确提交请求金额。
TypeScript
declare const brandKey: unique symbol;
type Brand<Value, Name extends string> = Value & {
readonly [brandKey]: Name;
};
type AccountId = Brand<number, "AccountId">;
type Cents = Brand<number, "Cents">;
type Transfer = { from: AccountId; to: AccountId; cents: Cents };
declare function sendTransfer(from: AccountId, to: AccountId, cents: Cents): void;
function parseTransfer(raw: string): Transfer {
const data = JSON.parse(raw) as Transfer;
return data;
}
function submitTransfer(raw: string, currentAccount: AccountId): void {
const transfer = parseTransfer(raw);
if (transfer.from !== currentAccount) throw new Error("forbidden");
const charged = transfer.cents + 25;
sendTransfer(transfer.from, transfer.to, charged as Cents);
}
生成代码仅作示例，不代表任何特定模型