Using sessions, the body/payload/multipart of the previous request is sent if not replaced.

[simue]

Description

I am using a session to send multiple sequential requests. Some are GET, some are POST.
On a GET that is sent after a POST, I see that the content_ of the first request being used as custom method, see example below.

[03/Feb/2025 22:33:14] code 501, message Unsupported method ('{"thisIsMyJsonBody": "OfThePreviousPostRequest"}GET')

I'd expect the session to either internally reset content_(maybe in makeRequest?), or if not possible, I'd expect there to be the possibility of resetting content_ explicitly.
Since content_'s default is std::monostate, I'd like to introduce a reset function, setting std::monostate.

Interestingly enough, there already is a function hasBodyOrPayload which generates a custom GET request and a comment stating GET with body is illegal. But no setter/reset for content_.

Example/How to Reproduce

1. Create a cpr::Session
2. Send POST
3. Send GET (without changing content_ via its various setters)
4. Perform the request
5. Observe method shown in server which contains the body of the POST request.

Possible Fix

See above, I'd like to introduce a reset function for content_.

Where did you get it from?

conan

Additional Context/Your Environment

• OS: Linux
• Version: custom on kernel 5.15

[simue]

I did some testing and have two observations:

• DifferentMethodTests.MultipleDeleteHeadPutGetPostTest reliably failed at a seemingly arbitrary, but reproducible point (?!) when I had a proxy set (still need to investigate this further).
• Even though a body (and relevant headers) is sent, the test case is still succeeding

I started modifying the test server so it always responds with some (base64 encoded?) json that contains information on what the request looked like to the server (all headers listed + full body). For tests that need to receive a custom message as well, that could also be placed in the json in a node, e.g. "userData". Leading to:

{
	"request": {
		"start_line": "POST /api/v1/echo HTTP/1.1",
		"headers": [
			{ "User-Agent": "curl/8.10.1" },
			{ "Content-Type": "application/json" },
			{ "Content-Length": "100" }
		],
		"body": "bodyAsPlainText(?)"
	},
	"userData": ""
}

But since this requires some work, I'd want to hear your opinion on this first.

[COM8]

@simue thanks for reporting and looking into this!

Yes, a clear content_ function would be a welcome addition.
Your approach with returning what has been sent to the sever is a valid one. If I think about it, I think it fits better into the current way of doing tests if we would check this on the mock server side to validate this and then return a specific error code.

What do you think about this?

[simue]

I like the approach you suggested and implemented it in #1179.
Let me know if/what you'd like to have changed.

I consider this a bugfix for 1.11. Since for other PRs you seem to be working towards 1.12.0 - are you open to do another 1.11.x bugfix release?
For that changes from #1173 would be quite handy, as well