commit c9a3cccb932d01232a56af8b2b0bf1352bccbd0a
parent a52774f43ccdad6c3af2ec76af27177d32f42a0c
Author: moonira <moonira@google.com>
Date: Wed, 26 Nov 2025 08:54:14 +0000
Bug 2001960 [wpt PR 56220] - Implement basic support for random() function, a=testonly
Automatic update from web-platform-tests
Implement basic support for random() function
Add random function to CSSMathExpressionNode.
Random base value cache [0] is stored on the Document.
There are two major remaining things:
1. Currently we don't store correct property name and property value
index in random caching key [1]. There are failing tests reflecting
that.
2. If a random() function can’t be simplified by computed value time,
then it should compute to its maximally-simplified form,
but with its <random-value-sharing> set to its random base value, [2].
This currently doesn't work correctly since we just resolve to
computed percentage value instead, i.e. same as min-max percentage
serialization doesn't work correctly in chrome [3].
Note: There are some failing tests that allows calc expressions and
random function inside fixed value, like:
random(fixed calc(2 / 4), 0px, 100px)
Though according to spec only numbers from 0 to 1
(fixed <number [0,1]>) should be allowed. These tests
should probably be removed.
Tests with invalidation to be added in the next CL.
[0] https://drafts.csswg.org/css-values-5/#random-caching
[1] https://drafts.csswg.org/css-values-5/#random-caching-key
[2] https://drafts.csswg.org/css-values-5/#random
[3] https://source.chromium.org/chromium/chromium/src/+/main:third_party/blink/web_tests/external/wpt/css/css-values/minmax-percentage-serialize-expected.txt
[4] https://drafts.csswg.org/css-values-5/#valdef-random-fixed
Bug: 413385732
Change-Id: I350a1c616d69302353c935dd12580f846ec59a53
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/7170451
Commit-Queue: Munira Tursunova <moonira@google.com>
Reviewed-by: Rune Lillesveen <futhark@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1549109}
--
wpt-commits: 403c505ccb6045b64d0276218fed4bd49645c060
wpt-pr: 56220
Diffstat:
1 file changed, 21 insertions(+), 11 deletions(-)
diff --git a/testing/web-platform/tests/css/css-values/random-computed.tentative.html b/testing/web-platform/tests/css/css-values/random-computed.tentative.html
@@ -50,6 +50,13 @@
// Run each test a number of times to increase the likelyhood that failure is not the cause of random chance.
const iterations = 5;
+// Since actual and expected values are generated randomly, `assert_equals()`
+// does not generate deterministic test failure output. Chrome relies on test
+// failure output to be deterministic and stable for failing test expectations.
+function test_random_equals(actual, expected, message = "Random values should be equal") {
+ assert_true(actual === expected, message);
+}
+
function test_random_computed_value(property, specified, computed, titleExtra, options = {}) {
if (!computed)
computed = specified;
@@ -68,12 +75,12 @@ function test_random_computed_value(property, specified, computed, titleExtra, o
} else if (Array.isArray(computed)) {
assert_in_array(readValue, computed);
} else {
- assert_equals(readValue, computed);
+ test_random_equals(readValue, computed);
}
if (readValue !== specified) {
target.style[property] = '';
target.style[property] = readValue;
- assert_equals(getComputedStyle(target)[property], readValue,
+ test_random_equals(getComputedStyle(target)[property], readValue,
'computed value should round-trip');
}
}
@@ -163,15 +170,15 @@ function test_random_computed_value_has_fixed(property, specified, minPercentage
// split fixed component into its two components
let [fixedString, fixedValue] = fixedComponent.split(' ');
- assert_equals(fixedString, 'fixed', specified);
+ test_random_equals(fixedString, 'fixed', `Computed value for ${specified} should include 'fixed'`);
if (expectedFixedValue) {
- assert_equals(parseFloat(fixedValue), expectedFixedValue);
+ test_random_equals(parseFloat(fixedValue), expectedFixedValue, `Random value for ${specified} should be ${expectedFixedValue}`);
} else {
assert_greater_than_equal(parseFloat(fixedValue), 0, specified);
assert_less_than(parseFloat(fixedValue), 1, specified);
}
- assert_equals(minComponent, minPercentage, specified);
- assert_equals(maxComponent, maxPercentage, specified);
+ test_random_equals(minComponent, minPercentage, specified);
+ test_random_equals(maxComponent, maxPercentage, specified);
}
}, `Property ${property} value '${specified}'${titleExtra ? ' ' + titleExtra : ''}`);
}
@@ -323,7 +330,7 @@ test(() => {
} finally {
document.body.removeChild(holder);
}
-}, `Maximum random - shorthand: random(a, b))`);
+}, `Maximum random - shorthand: random(a, b)`);
test(() => {
const holder = document.createElement('div');
@@ -338,7 +345,8 @@ test(() => {
let elComputedWidth = getComputedStyle(el)['width'];
let elComputedHeight = getComputedStyle(el)['height'];
- assert_equals(elComputedWidth, elComputedHeight);
+ test_random_equals(elComputedWidth, elComputedHeight,
+ "width and height values on same element should be equal");
}
} finally {
document.body.removeChild(holder);
@@ -384,7 +392,8 @@ test(() => {
let t1ComputedWidth = getComputedStyle(t1)['width'];
let t2ComputedWidth = getComputedStyle(t2)['width'];
- assert_equals(t1ComputedWidth, t2ComputedWidth);
+ test_random_equals(t1ComputedWidth, t2ComputedWidth,
+ "width values on different elements should be equal");
}
} finally {
document.body.removeChild(holder);
@@ -430,7 +439,8 @@ test(() => {
let t1ComputedWidth = getComputedStyle(t1)['width'];
let t2ComputedHeight = getComputedStyle(t2)['height'];
- assert_equals(t1ComputedWidth, t2ComputedHeight);
+ test_random_equals(t1ComputedWidth, t2ComputedHeight,
+ "width and height values on different elements should be equal");
}
} finally {
document.body.removeChild(holder);
@@ -472,7 +482,7 @@ test(() => {
let t1ComputedWidth = getComputedStyle(t1)['width'];
- assert_equals(t1ComputedWidth, "55px");
+ test_random_equals(t1ComputedWidth, "55px", "Random value with fixed should be 55px");
}
} finally {
document.body.removeChild(holder);
