Source code
Revision control
Copy as Markdown
Other Tools
Test Info:
/* Any copyright is dedicated to the Public Domain.
/* global getPropertyValue */
"use strict";
// Unit test for math behind conversion of units for letter-spacing.
const TEST_URI = `
<style type='text/css'>
body {
/* Set root font-size to equivalent of 32px (2*16px) */
font-size: 200%;
}
div {
letter-spacing: 1em;
}
</style>
<div>LETTER SPACING</div>
`;
add_task(async function () {
const URI = "data:text/html;charset=utf-8," + encodeURIComponent(TEST_URI);
const { inspector, view } = await openFontInspectorForURL(URI);
const viewDoc = view.document;
const property = "letter-spacing";
const UNITS = {
px: 32,
rem: 2,
em: 1,
};
await selectNode("div", inspector);
info("Check that font editor shows letter-spacing value in original units");
const letterSpacing = getPropertyValue(viewDoc, property);
is(
letterSpacing.value + letterSpacing.unit,
"1em",
"Original letter spacing is 1em"
);
// Starting value and unit for conversion.
let prevValue = letterSpacing.value;
let prevUnit = letterSpacing.unit;
for (const unit in UNITS) {
const value = UNITS[unit];
info(`Convert letter-spacing from ${prevValue}${prevUnit} to ${unit}`);
const convertedValue = await view.convertUnits(
property,
prevValue,
prevUnit,
unit
);
is(
convertedValue,
value,
`Converting to ${unit} returns transformed value.`
);
// Store current unit and value to use in conversion on the next iteration.
prevUnit = unit;
prevValue = value;
}
info(`Check that conversion to fake unit returns 1-to-1 mapping`);
const valueToFakeUnit = await view.convertUnits(property, 1, "px", "fake");
is(valueToFakeUnit, 1, `Converting to fake unit returns same value.`);
});