camunda/feel-scala

number() on a number returns null

LockeBirdsey opened this issue · 3 comments

LockeBirdsey commented

Describe the bug
Due to unexpected value types in a retrieved value, we sanitise types by number(value). When value is already a number, number(value) returns null

To Reproduce
Steps to reproduce the behavior:

  1. number("17") will return 17
  2. number(17) will return null

Expected behavior
number(value) should return a numeric representation of value unless there is no possible way for the cast to occur e.g. it is not a primitive.

To be fair, it makes sense that it returns null in this case and that we could further prevent against this issue by doing number(string(value)). Additionally the Zeebe docs do seem to say the input needs to be a string, so I'm not entirely certain if what I'm reporting is entirely valid or not.

Environment

  • Zeebe 8.1.4
saig0 commented

@LockeBirdsey thank you for raising this up. 👍

First of all, I understand your expectation.

But the current behavior matches the documentation since the function expects a string argument.

The behavior is also aligned with the DMN specification (chapter 10.3.4.1, page 138):

image

The number() function is only defined for string arguments. As a result, the function should return null for other arguments.

To sum it up, it is the expected behavior from the DMN perspective. So, we can't treat the behavior as a bug.

saig0 commented

@LockeBirdsey do you understand the reasoning? Can you agree with it?

Feel free to share your example. I could tweak the expression with you.

LockeBirdsey commented

Ahh yes that makes complete sense, thanks for the info!

I'll handle my problem in a different way then.

  • 👍1