Facilitate tests debugging in Antithesis

[mprimi]

1. Introduce dependency on antithesis-sdk-go (default NOOP variant)
2. Introduce assertions utilities suitable for use in tests
3. Instrument frequently used test utilities with the new assertions

N.B. unless the enable_antithesis_sdk tag is specified at build time, both the SDK and the assertions wrappers are NOOP, and should have no effect.

This will also facilitate other Antithesis one off experiments since developers no longer have to manually add the SDK to their branch.

Signed-off-by: Your Name [email protected]

[neilalexander]

I'm a bit confused about internal/antithesis/fallback_sdk.go here. Antithesis already produce default-no-op builds of their SDK, which contain all of the functionality, but only when built with the enable_antithesis_sdk tag. Wouldn't that be what we want?

[mprimi]

Antithesis already produce default-no-op builds of their SDK

I'll be honest, i didn't notice this release (it's not documented and wasn't brought up in discussion).
I also assumed (wrongly?) you'd not be comfortable bringing in the full SDK.

But if you are, then I agree using the official client is a great option.

I just launched a side-by-side comparison for the test flakes from last week, we should see the official client find the same violated assertions.

Assuming the two are equivalent in terms of results for that experiment, there's still a few minor differences and tradeoffs worth considering.

This fallback implementation gives us more control:

• Add additional behavior (e.g. stack trace on assert false is useful, even outside Antithesis), and more
• Control grouping and de-duplication by test (i.e. 2 distinct tests failing on the same require_* or waitFor* will produce 2 example traces. vs. the official client will produce a single trace/example per assertion violation)
• Control over panic or continue execution on assert violation
• No surprise breakage when upgrading dependencies

Of course there are upsides of using the official library:

• Less code to own/maintain, simpler upgrades
• Devs no longer need to go get antithesis in their branch when running one-off experiments

One more important distinction:

The fallback impl. is specifically for tests, it only exposes Assert(condition) and AssertUnreachable. Both take a *testing.T argument which means we won't end up using it by mistake in server code.

The official client is generic and has a much richer API suitable for the entire project, not just tests.
It exposes things like Reachable, Sometimes, which do not work properly inside a test context**. Devs may use these API count on the results without realizing they do not actually work.

So the richer API is a double-edged sword.

** Antithesis instrumentor skips test code => Assertions in tests code are not catalogued => Antithesis does not know of these assertion ahead of time => Antithesis cannot know it failed to reach a Reachable statement => There will be no failed Reachable property in the report. This can be misleading, as a failed property ins not reported.

[mprimi]

@neilalexander Ready for merge

[neilalexander]

Otherwise LGTM, thanks!

[neilalexander]

LGTM