Blitz - WPT: percentage-heights-003.html

wpt / css / css-flexbox / percentage-heights-003.html

Data from commit:
708eb61 WPT runner: support mismatch reftests and multiple rel=match links (#665) (2026-08-09)

Subtest	Status	Message
.flexbox 1	PASS
.flexbox 2	PASS
.flexbox 3	FAIL	assert_equals: data-expected-height expected 0 got 100
.flexbox 4	FAIL	assert_equals: data-expected-height expected 0 got 100
.flexbox 5	FAIL	assert_equals: data-expected-height expected 0 got 50 assert_equals: data-expected-height expected 0 got 50
.flexbox 6	PASS
.flexbox 7	PASS

Enable JavaScript in test iframe

/css/css-flexbox/percentage-heights-003.html

<!DOCTYPE html>
<html>
<title>CSS Flexbox: Resolving relative height content within a flex container against flexed size</title>
<link rel="author" title="Microsoft" href="https://www.microsoft.com/" />
<link rel="author" title="Greg Whitworth" href="gwhit@microsoft.com" />
<link rel="help" href="https://drafts.csswg.org/css-flexbox-1/#definite-sizes" />
<link rel="issue" href="https://github.com/w3c/csswg-drafts/issues/1679" />
<meta name="assert" content="This test checks that percentage heights of content within a flex item are resolved against the flexed item" />

<style>
.flexbox {
    display: flex;
    min-height: 100%;
}

.column {
    flex-flow: column;
}

.column-wrap {
    flex-flow: column wrap;
}

.flexbox > div {
    background: teal;
    flex-grow: 1;
}

.flexbox span {
    height: 100%;
    background: orange;
    display: block;
}
.vert-wm {
    writing-mode: vertical-rl;
}
.horiz-wm {
    writing-mode: horizontal-tb;
}
</style>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/resources/check-layout-th.js"></script>
<body onload="checkLayout('.flexbox')">
<div id=log></div>

<!-- The wrapper divs are here to give the flexbox something to fill  -->

<!-- definite unwrapped column flexbox -->
<div style="height: 100px;">
    <div class="flexbox column" style="height: 0">
        <div>
            <span data-expected-height="100"></span>
        </div>
    </div>
</div>

<!-- definite wrapped column flexbox -->
<div style="height: 100px;">
    <div class="flexbox column-wrap" style="height: 0">
       <div>
            <span data-expected-height="50"></span>
        </div>
        <div>
            <span data-expected-height="50"></span>
        </div>
    </div>
</div>

<!-- indefinite unwrapped column flexbox -->
<div style="height: 100px;">
    <div class="flexbox column">
        <div>
            <span data-expected-height="0"></span>
        </div>
    </div>
</div>

<!-- indefinite unwrapped column flexbox where item doesn't stretch -->
<div style="height: 100px;">
    <div class="flexbox column">
        <div style="align-self: flex-start">
            <span data-expected-height="0"></span>
        </div>
    </div>
</div>

<!-- indefinite wrapped column flexbox -->
<div style="height: 100px;">
    <div class="flexbox column-wrap">
       <div>
            <span data-expected-height="0"></span>
        </div>
        <div>
            <span data-expected-height="0"></span>
        </div>
    </div>
</div>

<!-- indefinite unwrapped column flexbox, with orthogonal-flow flex item. The
     flex item's main size (height) is definite, since it's the item's inline
     size, and inline sizes always end up definite. -->
<div style="height: 100px;">
    <div class="flexbox column">
        <div class="vert-wm">
            <span data-expected-height="100"></span>
        </div>
    </div>
</div>

<!-- indefinite unwrapped row-oriented vertical-writing-mode flexbox, with
     orthogonal-flow (horizontal-writing-mode) flex item. The flex item's
     height (main size) is definite, since its parent flex container has a
     definite main size, because the flex container's main axis is its
     inline-axis and inline sizes are definite. -->
<div style="height: 100px;">
    <div class="flexbox vert-wm">
        <div class="horiz-wm">
            <span data-expected-height="100"></span>
        </div>
    </div>
</div>

</body>
</html>