css/css-text/letter-spacing/letter-spacing-ligatures-001.html

<!DOCTYPE html>
<html  lang="en" >
<meta charset="utf-8">
<title>text-justify:inter-character and ligatures</title>
<link rel='author' title='Florian Rivoal' href='https://florian.rivoal.net'>
<link rel='help' href='https://drafts.csswg.org/css-text-3/#letter-spacing-property'>
<link rel='match' href='reference/letter-spacing-ligatures-001-ref.html'>
<meta name=flags content="should">
<meta name="assert" content="When the effective spacing between two characters is not zero (due to either justification […]), user agents should not apply optional ligatures">
<style>
@font-face {
    font-family: 'mplus';
    src: url('/fonts/mplus-1p-regular.woff');
}
div {
    font-size: 2em;
    font-family: mplus;
    width: 12ch;
    text-align: justify;
    text-align-last: justify;
    text-justify: inter-character;
    font-kerning: none;
}
span {
    display: inline-block;
    text-justify: auto;
}
.ref { color: blue; font-variant-ligatures: none; }
.noref { color: orange; }
</style>
<p>Test passes if the black text looks like the blue one, not the orange one.
<div>office</div>
<div class=ref>office</div>
<div class=noref>o<span>ffi</span>ce</div>