In $http docs it does not mention which is the default timeout in case of undefined.
How can I know which is the default value for this configuration?
At one time the default timeout for http requests was 30 seconds, but now many browsers perform "keep-alive" polling by default so in all practicality there isn't one. I've had http requests sit for several minutes before the server itself finally gave up and issued a timeout.
来源：https://stackoverflow.com/questions/37547229/what-is-the-default-timeout-for-angularjs-http-service-requests