Don't print non-utf8 bodies

[xd009642]

A lot of our services take in multipart data or binary data in the HTTP body and when a wiremock predicate fails megabytes of binary data get printed out to the console. Here I address this by not printing out a string if it isn't valid utf8 and instead printing out the body length.

Another alternative may be to put in an upper limit to how large a body will be printed and if it exceeds that size maybe saving the request to a file for later analysis. But this change was so simple I figured I'd open the PR first to start the discussion.

Issue: #124

[xd009642]

I am slightly erring towards just putting a if self.body.len() > THRESHOLD and doing something else instead and keeping old from_utf8_lossy behaviour for body <= THRESHOLD.

Edit: Remove mention of cloning forgot about std::str::from_utf8

[LukeMathWalker]

I think it's a good idea to tweak the default behaviour.
I'd suggest:

• Having a default size threshold
• Only printing the body if it is UTF8

We can then provide a knob in the server config to bypass these checks and print the body anyway. It should also be possible to do it via an env variable, which should be mentioned in the printed message when the body is not outputted in full.

Wdyt?

[xd009642]

Sure sounds good to me, I'll add the env var, default threshold and method to configure it 👍

[xd009642]

Okay the way I've implemented this is by passing it from the builder, adding as a field in the request store and request and setting it accordingly. I didn't see any other env var configs in the code via a quick grep so just did something that felt right (though it could log invalid env var values).

Didn't add in examples to docs or flesh them out too much as the code may change if you don't like the approach, just enough docs to illustrate my intent and not take up too much thinking.

[xd009642]

Applied all the feedback, ready for another round of review 😄

[xd009642]

One note I see the coverage job failed and you're using actions-rs/tarpaulin, I generally wouldn't use it because it's unmaintained abandonware and since tarpaulin has windows and mac releases the release tarball name has changed. cargo-binstall is generally my recommended way of using it in CI 👀

[LukeMathWalker]

Yeah, I need to update the CI pipeline 😅