commit 2c67022fcbacef33b1090e1eb0008e9af7ed6181
author Traian Captan <tcaptan@chromium.org> Tue Apr 23 22:58:08 2024
committer Blink WPT Bot <blink-w3c-test-autoroller@chromium.org> Tue Apr 23 23:07:51 2024
tree 1e37297c36289ab6b48695957739939f976a6c85
parent 9e7e1bd19fecd541ce4192e24039b746a88ce3df

StepDown should default to min when no current val

When `stepDown()` is called on an input box that has a minimum value
defined that is greater than zero and no current value, no value is
set.

This can seem unintuitive to users and mismatches what currently
happens when the user uses the spinner or keyboard down arrow.

The reason for nothing seeming to happen is due to interpretation of
step 10 in the stepDown(n) method specified algorithm [1]:
"10. If either the method invoked was the stepDown() method and value
is greater than valueBeforeStepping, or the method invoked was the
stepUp() method and value is less than valueBeforeStepping, then
return."

when applying the default value in step 5:
"5. If applying the algorithm to convert a string to a number to the
string given by the element's value does not result in an error, then
let value be the result of that algorithm. Otherwise, let value be
zero."

If the minimum value defined for the input is greater than the default
of zero, the check in step 10 fails and an early return is executed.

The proposed fix for this is to keep track of whether there was an
actual `valueBeforeStepping` (current value) or the default is used,
and execute the early return defined in step 10 only if the default
was not used. This will result in a more intuitive behavior for the
users, and align the `stepDown()` behavior in this case with the
spinner/keyboard arrow down behavior and also match FireFox.

[1]https://html.spec.whatwg.org/multipage/input.html#dom-input-stepup

Bug: 40692746
Change-Id: Ie4cabb9169911f8c8cb0149c716133f0a1951cb8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5474199
Reviewed-by: Mason Freed <masonf@chromium.org>
Commit-Queue: Traian Captan <tcaptan@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1291586}