Make debugging unmatched requests easier

[amosjyng]

Hey, thanks for the great library! I added some print statements in my fork because I found it cumbersome to debug failing tests. I can hide this logic behind a flag or something if you're interested in merging this PR

[mksh]

Hello! Thank you for the contribution. This idea looks good overall, but PR needs some changes to get it through

• please make diff printing functionality to be optional, with VCRMiddleware method named like with_rich_diff turning it on
• please use tracing::info! macro to print diff instead of eprintln!(), so output can be managed by RUST_LOG environment configs
• please add integration test that has unmatched request sent, and verifies the diff is printed in correct form (can use tracing-test https://github.com/dbrgn/tracing-test library to capture what is being printed in tests).

Thanks in advance!

[amosjyng]

Thanks for the review! I'm currently trying to make a deadline, but I'll give this a pass in a few weeks if that's ok :)

[mksh]

Yeah that's fine for sure, follow up on your discretion I am always open for review!

[amosjyng]

Ok, I've made an initial pass at implementing the suggestions! Some notes:

• I changed the implementation of Middleware.handle to return a reqwest_middleware::Error::Middleware instead of panicking, because it seems hard to test for emitted logs after panicking. In particular, catch-unwind does not take async functions. This would also allow for usage of this library in non-test contexts.
• Due to the above, I added anyhow as a crate dependency because request-middleware v0.1.6 depends on anyhow already, and reqwest_middleware::Error expects an anyhow::Error
• While tracing_test::traced_test successfully prints out the entire debug output, it appears to only save the first line when it comes time to call logs_contain. As such, I split each line of output when emitting the trace, and recombine them at the end of the test.

Let me know what you think :)

[mksh]

LGTM

[mksh]

Released 0.2.1 version with changes: https://crates.io/crates/rvcr/0.2.1

[amosjyng]

Nice, thank you!