* Update tests to be compatible with jQuery 3.0.0
There was a change in jQuery 3 that ensures that the return value of `.val()` on a multiple select is always an array. This is a breaking change from previous versions, where `null` or `undefined` were returned in these scenarios. Because we cannot `assert.equal` on a list of possible values, these assertions were switched to `assert.ok` which should be good enough.
* Properly strip out units in positioning tests
Before we were assuming that there were no units, and only were we stripping them out if we were expecting 3 digits. Now we just strip out all non-digit characters, so that should do the job and get us what we want.
There was a change in jQuery 3.2.0 that caused the units to be returned in these specific calls. They were not previously being returned, so this was not actually an issue.
* Add automated testing against jQuery 3.4.1
No tests appear to be currently failing.
After we upgraded to QUnit 1.23.1, we gained support for
assert.expect(). This allows us to guard against any race conditions
within tests, because now expect() will be linked to the specific test
instead of the current running test.
These tests did not cover the classes that should have been
automatically applied to the dropdown based on the space around it. Now
they both test that the dropdown should be facing down, because there is
enough space below it to display the dropdown.
This fixes the two failing assertions that only triggered in IE 9 (no
other versions) and Firefox. Both of them were caused by the offset for
the dropdown including a constant extra amount, what appeared to be
related to the size of the container if it actually had content. This
was not consistent in browsers, so now we are forcing there to be a
small amount of content within the container and then calculating the
expected offset based on that height.
There was a commit that landed in 4.0.1 that fixed positioning for
non-static elements, which are commonly used for the custom
`dropdownParent` option, but broke positioning for statically positioned
elements, commonly used in almost every other case. That commit was
c9216b4b96
This fixes the positioning issues caused by that commit by properly
calculating the offsets for statically positioned parents. Statically
positioned parents are unique, because the offset for the dropdown must
be calculated based on the closest element that is non-statically
positioned. Otherwise, the offset for any statically positioned parent
other than the body will be considerably higher than it should be,
resulting in the dropdown being offset by a large amount.
The offset parent for the body element is the html element, which is why
this works for both the body element and any custom parents for the
dropdown. This would not be needed if the parent wasn't customizable (as
seen in Select2 3.x) because you will never need to offset the body
element if it is statically positioned, because the html element almost
never has an offset.
This also fixes JSHint issues within the tests added in the last commit.
This closes https://github.com/select2/select2/issues/3970
This closes https://github.com/select2/select2/issues/3639
This adds a regression test that verifies the problem with positioning
the dropdown when the parent is a statically positioned element that
still has an offset. This could typically be seen if the body element
has an offset, which unfortunately it almost always does because of the
default user stylesheet in browsers. This was not caught during
pre-release testing because all of the test pages reset the margins and
padding on the body element.
This regression test verifies that the offsets that should be set for
the dropdown are calculated correctly. These were surprisingly difficult
to do because of how the offset is calculated using different
positioning techniques.
These tests are for https://github.com/select2/select2/issues/3970
