Improve usage checks in Request and Websocket

[gavv]

Request and Websocket have the following workflow:

• create instance
• likely, call WithXXX() methods multiple times
• call Expect() method

It is not allowed to call WithXXX() after Expect() is called. It is also not allowed to call Expect() more than once. However, these requirements are not documented and checked.

What we should do:

• Document these requirements in comment for Expect.
• Report failure if these requirements are violated with Type set to AssertUsage and an explanatory message.
• Add unit tests that cover these failure reports.

[chunweii]

Hi @gavv, may I work on this?

I am not sure how to check for the violations. The WithXXX() and Expect() functions are only available for both Request and Websocket structs. The Expect() function returns a *Response or a *WebsocketMessage which do not have the Expect() function. If the user of this library makes this mistake, then the code would fail to build. Doesn't this already check for the violations?

[gavv]

Hi,

I mean the follwoing misuses:

req := e.GET("/test")

req.WithXXX(...) // ok
req.WithXXX(...) // ok
req.Expect() // ok

req.WithXXX() // bad, With not allowed after Expect; should report failure
req.Expect() // bad, multiple Expect calls not allowed; should report failure

[gavv]

Let me know if you would like to be assigned.

[chunweii]

Yes please, thanks!

[chunweii]

For Websocket, some of the tests in e2e calls Expect() multiple times. If the usage checks are implemented, these tests will fail.

[gavv]

Oh, you're right. Websocket.Expect is intended to be called multiple times, once for each message. Seems it's also okay to call WithXxx methods between Expect calls.

So no modifications are needed in Websocket, this issue is relevant only for Request.