Feature Request - Orquesta inspection of when expressions

SUMMARY

Recently in Slack there have been several help requests that all were caused by people introducing logic errors into when expressions in task transitions. When these logic errors are made they result in the when expression always evaluating to true/false and Orquesta either taking always an unexpected branch (in the case of the expression always evaluating to True) and never taking the branch they expect (in the case where the expression always evaluates to False)

This request is to help detect these kinds of errors and warn/fail the workflow to help the user.

ISSUE TYPE

• Feature Idea

STACKSTORM VERSION

2.10.2

PROBLEM EXPRESSIONS

Mis-typed state functions

Bad Expression:

when: <% succeeded %>

Logic Error:

• The user thought that they were executing only when the task succeeded, but their expression instead was returning the string succeeded which then evaluated to True and caused that branch to always be taken

Proper Expression:
What the user really wanted was to use the succeeded() function.

when: <% succeeded() %>

Logic outside of expression delimeters

Bad Expression:

when: <% ctx().foo %> and <% ctx().bar %>

Logic Error:

• The user thought that they were combining two expressions logically with the and keyword. Instead they were creating a string "foo's value and bar's value". This string is non-empty so evaluates to True and causes the branch to be taken no matter the values of ctx().foo and ctx().bar.

Proper Expression
What the user really wanted was to put the logic keyword inside of the expression delimiters

when: <% ctx().foo and ctx().bar %>

The issue names no files, tests, or entry points. Start by locating Orquesta's handling of task-transition when expressions and review the two malformed examples; done should include detection that warns or fails workflows for these logic errors.