Flow预期自定义对象类型上会出现类型错误，但不会引发任何错误

Question

我试图通过从头开始构建Web服务器来变得更加熟悉JS。我具有以下用于初始化基本Web服务器的类：

// @flow

'use strict';

import fs from 'fs';

type CertPath =  { key: string, cert: string };

export class Server {
    constructor(certPaths: CertPath){
        this.setCertPath(certPaths)
    }

    certPath: CertPath;
    forceSecure = false;
    https = require('https');
    port = 443;

    setCertPath = (certPaths: Object) => {
        this.certPath = certPaths;
    };

    connection = this.https.createServer({
        key: fs.readFileSync(this.certPaths.key),
        cert: fs.readFileSync(this.certPaths.cert)
    });

    forceSecureConnection = (bool = true) => {
        this.forceSecure = bool;
        return this;
    };

    enableServer = (port = 443) => {
        this.port = port;
        this.connection.listen(port, '127.0.0.1');
    };
}

然后我将启动服务器：

const web = new Server("Throw some error, PLEASE!");
web.enableServer();

由于https://github.com/facebook/flow/issues/1409，我不希望CertPath类型在构造函数中失败。但是，如果执行this.certPath = 'anything other than type CertPath'

，我确实希望它会失败

这是我的.babelrc

{
  "presets": [
    "flow",
    ["env", {
      "targets": {
        "node": "current"
      }
    }]
  ],
  "plugins": [
    "transform-class-properties"
  ]
}