Struct ProbeSpec 

pub struct ProbeSpec {
    pub id: &'static str,
    pub subject: Subject,
    pub results: usize,
    pub always: bool,
    pub run: for<'a> fn(&'a Ctx) -> ProbeFuture<'a>,
}

One entry in the suite.

A step may emit several ProbeResults — identity alone produces seven — so the unit of selection is coarser than the unit of reporting. That is deliberate: the multi-result steps share state and sampling between their parts, and letting a caller pick half of one would silently change what the other half means.

Fields

id: &'static str

Stable across releases. Callers persist these, filter on them, and localise labels from them, so renaming one is a breaking change.

subject: Subject

results: usize

How many results this step contributes, for progress totals. Steps whose output depends on what earlier steps observed report their maximum.

always: bool

Runs regardless of the caller’s subject filter, because the rest of the suite is meaningless without it.

run: for<'a> fn(&'a Ctx) -> ProbeFuture<'a>