因此，我通过编译为 es2017 而不是 es6 解决了该问题.

So, I resolved the issue by compiling to es2017 instead of es6.

我注意到当我将 async 函数传递给 express 路由器时，会发生此问题.但是，返回 Promise 的函数没有问题.

I noticed the issue occurs when i pass async functions to the express router. Yet, functions returning a Promise had no issue.

我发现问题是，当将TypeScript代码编译为 es6 时，它会转换

I found the problem was that when compiled TypeScript code to es6 it converts

async function() {...

到

__awaiter(this, void 0, void 0, function* () {...

这是 Generator 发挥作用的地方.看来 express 在处理请求后无法正确释放它.由于 es2017 支持 async 功能，因此这不再是问题.

This is where Generators come in play. It looks like express cannot correctly free this after handling a request. Since es2017 supports async function this is not a problem anymore.

另外，我还必须删除软件包 express-validator ，因为他们的验证中间件已编译为相同的 Generator 结构.

Additionally I had to remove the package express-validator, because their validation middleware was compiled to the same Generator structure.