False positives from `toHaveStyle`

[jmpainter]

• @testing-library/jest-dom version: latest

Relevant code or config:

The following assertions will always pass if the element doesn't have that CSS property set in style:

expect(element).toHaveStyle("border: fakefake");
expect(element).toHaveStyle("background: fakefake");

Suggested solution:

Fix needs to be made in to-have-style.js getStyleDeclaration. expected will be '' (empty string) in toHaveStyle.