Color-contrast rule returns incomplete and claims node is partially obscured

[straker]

Run Axe on https://straker.github.io/kontra/.

Expectation: Color contrast should pass

Actual: Color contrast returns incomplete for all nodes under the fold claiming the elements are partially obscured, even though no element obscures it.

I tried to figure out why the rule fails with @scurker, but we both gave up after we couldn't reproduce a reliable test case that worked consistently.

The best we could determine is that when the color-contrast rule tries to determine the background color of the element, it thinks document.body does not visually contain the element. We thought it was because there is an inner scroll element <main> that captures the scroll instead of the body itself, so body never scrolls. But any time we tried to create a test case to reproduce that, the color-contrast rule would pass.

In summary: we think the code for color.getBackgroundColor scrolling the element with scrollIntoView is not scrolling the body element, so when checking dom.visuallyContains, the element fails for document.body.

axe-core version: 3.2.2
axe-devtools 3.8.0
browser: Chrome

[robertvrabel]

I'm having a similar issue. It looks like when putting a background-color on the body element it throws off the color-contrast check.

If you move it to the html element instead it seems to resolve the issue.

[jeankaplansky]

ID'd as color-contrast issue. We're going to make one entry into the release notes for all color-contrast fixes/enhancements.

[jeankaplansky]

ID'd as color-contrast issue. We're going to make one entry into the release notes for all color-contrast fixes/enhancements.

[padmavemulapati]

@straker , ran axe on, https://straker.github.io/kontra/ , I am seeing "all issues (17)" count, and all 17 were under "Needs to review" section. Verified with the latest axe. What is the expected behaviour here?

[padmavemulapati]

Now with the latest axe, getting all issues(17) in "Incomplete", working as expected.

[padmavemulapati]