I needed to use element.classList.contains('some-class') to check if an element contains at least one of three classes, so I wrote:

if (element.classList.contains('class1', 'class2', 'class3')) {

  // do stuff here

}

The result was - if the element has 'class1', it returns true, no matter if it has 'class2' or/and 'class3', and
// do stuff here
executes. However, if it has 'class2' and/or 'class3', it returns false and
// do stuff here
does not execute.

I worked around it with:

if (element.classList.contains('class1') || element.classList.contains('class2') || element.classList.contains('class3')) {

  // do stuff here 

}