Core: Introduce `deviatesAround` assertion target

I mean something like this:

.assertions(
    global.requestPerSec(target=10, deviation=.05, inclusive=true),

)

where “target” is target intensity and “deviation” is deviation in percent.

[slandelle]

The syntax wouldn’t work with Gatling DSL. target and deviation should be defined on the target, not on the metric.

With #3845, we have:

global.requestsPerSec.around(mean = 10, plusOrMinus = 5, inclusive = true)

where plusOrMinus is an absolute value.

How should we have a way to define plusOrMinus as a percentage of the mean? Additional boolean?

Contributions welcome.

Please note that such contribution have to land before we release 3.4.0 or it will be too late.

[slandelle]

You can’t push on gatling’s own repo. You have to fork it, push there and then create a PR.