css/css-values/round-function.html

<!doctype html>
<title>round() function</title>
<meta charset=utf-8>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="../support/numeric-testcommon.js"></script>

<meta name=author content="Tab Atkins-Bittner">
<link rel=help href="https://drafts.csswg.org/css-values-4/#round-func">

<div id=target></div>
<script>
// No-op round should be same as nearest
test_math_used("round(23px, 10px)", "20px");
test_math_used("round(18px, 10px)", "20px");
test_math_used("round(15px, 10px)", "20px");
test_math_used("round(13px, 10px)", "10px");
test_math_used("round(-13px, 10px)", "-10px");
test_math_used("round(-18px, 10px)", "-20px");

// Test nearest
test_math_used("round(nearest, 23px, 10px)", "20px");
test_math_used("round(nearest, 18px, 10px)", "20px");
test_math_used("round(nearest, 15px, 10px)", "20px");
test_math_used("round(nearest, 13px, 10px)", "10px");
test_math_used("round(nearest, -13px, 10px)", "-10px");
test_math_used("round(nearest, -18px, 10px)", "-20px");

// Test down
test_math_used("round(down, 23px, 10px)", "20px");
test_math_used("round(down, 18px, 10px)", "10px");
test_math_used("round(down, 15px, 10px)", "10px");
test_math_used("round(down, 13px, 10px)", "10px");
test_math_used("round(down, -13px, 10px)", "-20px");
test_math_used("round(down, -18px, 10px)", "-20px");

// Test up
test_math_used("round(up, 23px, 10px)", "30px");
test_math_used("round(up, 18px, 10px)", "20px");
test_math_used("round(up, 15px, 10px)", "20px");
test_math_used("round(up, 13px, 10px)", "20px");
test_math_used("round(up, -13px, 10px)", "-10px");
test_math_used("round(up, -18px, 10px)", "-10px");

// Test to-zero
test_math_used("round(to-zero, 23px, 10px)", "20px");
test_math_used("round(to-zero, 18px, 10px)", "10px");
test_math_used("round(to-zero, 15px, 10px)", "10px");
test_math_used("round(to-zero, 13px, 10px)", "10px");
test_math_used("round(to-zero, -13px, 10px)", "-10px");
test_math_used("round(to-zero, -18px, 10px)", "-10px");

// Test a negative step
test_math_used("round(23px, -10px)", "20px");
test_math_used("round(18px, -10px)", "20px");
test_math_used("round(15px, -10px)", "20px");
test_math_used("round(13px, -10px)", "10px");
test_math_used("round(-13px, -10px)", "-10px");
test_math_used("round(-18px, -10px)", "-20px");

// Extreme cases:

// 0 step is NaN
test_nan("round(5, 0)");
// both infinite is NaN
test_nan("round(infinity, infinity)");
test_nan("round(infinity, -infinity)");
test_nan("round(-infinity, infinity)");
test_nan("round(-infinity, -infinity)");

// infinite value with finite step is the same infinity
test_plus_infinity("round(infinity, 5)");
test_plus_infinity("round(infinity, -5)");
test_minus_infinity("round(-infinity, 5)");
test_minus_infinity("round(-infinity, -5)");

// Finite value with infinite step depends on rounding strategy.
// 'nearest' and 'to-zero': pos and +0 go to +0, neg and -0 go to -0
test_plus_zero("round(5, infinity)");
test_plus_zero("round(5, -infinity)");
test_minus_zero("round(-5, infinity)");
test_minus_zero("round(-5, -infinity)");
test_plus_zero("round(to-zero, 5, infinity)");
test_plus_zero("round(to-zero, 5, -infinity)");
test_minus_zero("round(to-zero, -5, infinity)");
test_minus_zero("round(to-zero, -5, -infinity)");
// 'up': pos goes to +inf, 0+ goes to 0+, else 0-
test_plus_infinity("round(up, 1, infinity)");
test_plus_zero("round(up, 0, infinity)");
test_minus_zero("round(up, -1 * 0, infinity");
test_minus_zero("round(up, -1, infinity");
// 'down': neg goes to -inf, -0 goes to -0, else 0+
test_minus_infinity("round(down, -1, infinity)");
test_minus_zero("round(down, -1 * 0, infinity)");
test_plus_zero("round(down, 0, infinity)");
test_plus_zero("round(down, 1, infinity)");
</script>