expected output of an empty string in spacing properties

[s-cork]

Dependencies check up

• I have verified that I use latest version of all @mantine/* packages

What version of @mantine/* packages do you have in package.json?

7.7.2

What package has an issue?

@mantine/core

What framework do you use?

Other, I will specify in the bug description

In which browsers you can reproduce the issue?

All

Describe the bug

I don't think it's intended behvaior
but an empty string for something like mt in the style props leads to the output marginTop: calc(0px * (...))
I would expect an empty string to be treated like undefined

(Similar to how it is in react, and css generally)

If possible, include a link to a codesandbox with a minimal reproduction

(set mt="" on any component and inspect the element)

Possible fix

in createConverter
this line is true for empty strings

      // Number("") -> 0
      if (!Number.isNaN(Number(replaced))) {

so we should explicitly check for empty string

There's also a corollary of this, that if you have extra spaces in your prop, then you get weird things in the output e.g. mt=" 4px"
calc(0rem * var(--mantine-scale)) calc(0.25rem * var(--mantine-scale))

The str.split.join function in the same place could be a bit cleverer
(getting blocks of non-space characters, rather than splitting on spaces)

Self-service

• I would be willing to implement a fix for this issue