Refactor testing utilities

[aryan-25]

Motivation:

We currently have two mechanisms for testing NIOHTTPServer in an end-to-end manner. The first mechanism involves starting up NIOHTTPServer on localhost, and setting up a NIO client (backed by NIO's ClientBootstrap) to send requests / observe responses. The second mechanism involves spoofing a NIOAsyncTestingChannel as the channel NIOHTTPServer runs on, wiring a client channel (also backed by a NIOAsyncTestingChannel) to the server channel, and writing/reading to/from the client channel.

Currently, both mechanisms share some duplicated code, have no documentation, and in general are poorly named/structured. We should improve this.

Modifications:

• Functionality of the existing Client type broken down into extensions on Channel and ClientBootstrap.

  • This enables code re-use in the client setup for the NIOAsyncTestingChannel-based mechanism.

• The NIOAsyncTestingChannel-based mechanism is now structured into TestingChannelHTTP1Server and TestingChannelSecureUpgradeServer.

• Added documentation for all test utilities and some general refactoring.

Result:

Easier to write more involving tests.