Description

Problem

In stepwise execution, every call to handler.run_step() checks if the workflow is done or if the next step should be unblocked for execution. Before this PR, unless workflow is not done, run_step assumes the previous step has returned, which is not true if the step itself awaits on something.

Solution

With this PR, a new functionality was added to the Context to keep track of step functions that have been called and are mid-flight (i.e. they haven't returned yet). Using this feature, run_step can now wait for a step to finish before moving on with the next step in line.

Fixes #17898

Type of Change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

Your pull-request will likely not be merged unless it is covered by some form of impactful unit testing.

• I added new unit tests to cover this change
• I believe this change is already covered by existing unit tests