Assertion
Overview
An Assertion step is mainly a step a used for testing flows, and rarely finds its way into live production flows once they are complete. The success or failure of an Assertion Step will fail the flow making it useful for testing as once the Assertion step is set up the flow can be rerun until Assertion passes.
Assertion Step
Imagine a scenario where you are building a flow and want to validate that certain properties output from a Map Step are shaped correctly. However you don't want to actually send this data to a target system quite yet.
In this scenario you can use an Assertion Step to run a test of the flow and validate in the data looks correctly. This can prevent many round trips to the target App or needing to send data and then Delete the data from this target App.
We advise against using this step in Production flows once they are completed as there are much better ways of validating outcomes of things like Actions. The recommended approach is to use Stop Steps which allow for the setting of business results and can provide much more detail about the outcome of a flow good or bad to those supporting it than a Assertion Step will.