tsoracle-failpoint

The one failpoint! macro shared across tsoracle — a thin wrapper over fail-rs that every crate re-uses instead of redefining its own copy.

Why it exists

Four crates (tsoracle-paxos-toolkit, tsoracle-openraft-toolkit, tsoracle-driver-file, tsoracle-server) each carried a byte-identical wrapper macro that forwarded to fail::fail_point! under a failpoints feature and expanded to () otherwise. Every change to failpoint semantics had to be made N times, and the macro had even drifted in name (fail_point! vs failpoint!). This crate is the single home for that wrapper.

What's in the box

• failpoint!(name) / failpoint!(name, closure) — the macro consumers sprinkle into synchronous code paths. Inert (()) with the failpoints feature off; under the feature, forwards to fail::fail_point! so a test can arm a panic, an error return, a pause, or a sleep at the named site.
• A failpoints-gated re-export of fail (tsoracle_failpoint::fail), so test code arms the process-global registry through the same crate the macro lives in — consumers never name fail directly.

Quick reference

Opt in by declaring a feature on the consumer crate that flips tsoracle-failpoint/failpoints:

# consumer Cargo.toml
[features]
failpoints = ["tsoracle-failpoint/failpoints"]

[dependencies]
tsoracle-failpoint = { workspace = true }

Then at the source site:

tsoracle_failpoint::failpoint!("file_driver::write_blocked");

And in a test (with the feature on):

let _scenario = tsoracle_failpoint::fail::FailScenario::setup();
tsoracle_failpoint::fail::cfg("file_driver::write_blocked", "panic").unwrap();

With failpoints off (production), the macro expands to nothing and fail is not linked.

Feature flags

• failpoints (off by default) — enables the macro body, pulls in fail, and enables fail/failpoints. Production builds carry zero overhead.

Related

• fail — the synchronous failpoint library this wraps.
• tsoracle-yieldpoint — the async analogue, for sites that must keep yielding their tokio worker while parked instead of blocking the thread.