chromium/third_party/blink/web_tests/external/wpt/css/css-fonts/variations/font-weight-matching.html

<!DOCTYPE html>
<html>
<head>
    <title>Testing new font-matching algorithm for font-weight values introduced in CSS Fonts level 4</title>
    <link rel="help" href="https://www.w3.org/TR/css-fonts-4/#font-matching-algorithm" />
    <script src="/resources/testharness.js"></script>
    <script src="/resources/testharnessreport.js"></script>
    <style>

        .testcase {
            float:left;
            margin: 5px;
            font-size:48pt;
            font-feature-settings: "kern" 1;
            color: rgba(0,0,0,0.5);
            background: linear-gradient(to left, lime 0%, lime 91px, red 91px);
        }

        @font-face {
            font-family: fontMatch;
            src: local('CSSTest Weights 900'), url('./resources/csstest-weights-900-kerned.ttf');
            font-weight: 100;
        }

        @font-face {
            font-family: fontMatch;
            src: local('CSSTest Weights 800'), url('./resources/csstest-weights-800-kerned.ttf');
            font-weight: 250;
        }

        @font-face {
            font-family: fontMatch;
            src: local('CSSTest Weights 700'), url('./resources/csstest-weights-700-kerned.ttf');
            font-weight: 400;
        }

        @font-face {
            font-family: fontMatch;
            src: local('CSSTest Weights 600'), url('./resources/csstest-weights-600-kerned.ttf');
            font-weight: 450;
        }

        @font-face {
            font-family: fontMatch;
            src: local('CSSTest Weights 300'), url('./resources/csstest-weights-300-kerned.ttf');
            font-weight: 500;
        }

        @font-face {
            font-family: fontMatch;
            src: local('CSSTest Weights 200'), url('./resources/csstest-weights-200-kerned.ttf');
            font-weight: 750;
        }

        @font-face {
            font-family: fontMatch;
            src: local('CSSTest Weights 100'), url('./resources/csstest-weights-100-kerned.ttf');
            font-weight: 900;
        }

    </style>
</head>
<body>

    <span style="position: absolute; top: -100vh;">
        <span style="font-family: fontMatch; font-weight: 100;">A</span>
        <span style="font-family: fontMatch; font-weight: 250;">A</span>
        <span style="font-family: fontMatch; font-weight: 400;">A</span>
        <span style="font-family: fontMatch; font-weight: 450;">A</span>
        <span style="font-family: fontMatch; font-weight: 500;">A</span>
        <span style="font-family: fontMatch; font-weight: 750;">A</span>
        <span style="font-family: fontMatch; font-weight: 900;">A</span>
    </span>

    <div id="testcases" style="overflow: hidden">
        <!--
            These testcases work using the new kerned CSSTest Weights fonts.
            The letter A and its corresponding numeric digit kern as one character.
        -->
        <div class="testcase" style="font-family:'CSSTest Weights W2569'; font-weight: 375;">
            A2
        </div>
    </div>

    <script>

        var testFontFaceMatch = [
            { weight:  99, expectedFont: "CSSTest Weights 900" },
            { weight: 100, expectedFont: "CSSTest Weights 900" },
            { weight: 249, expectedFont: "CSSTest Weights 900" },
            { weight: 250, expectedFont: "CSSTest Weights 800" },
            { weight: 399, expectedFont: "CSSTest Weights 800" },
            { weight: 400, expectedFont: "CSSTest Weights 700" },
            { weight: 420, expectedFont: "CSSTest Weights 600" },
            { weight: 470, expectedFont: "CSSTest Weights 300" },
            { weight: 500, expectedFont: "CSSTest Weights 300" },
            { weight: 600, expectedFont: "CSSTest Weights 200" },
            { weight: 750, expectedFont: "CSSTest Weights 200" },
            { weight: 751, expectedFont: "CSSTest Weights 100" },
            { weight: 900, expectedFont: "CSSTest Weights 100" },
            { weight:1000, expectedFont: "CSSTest Weights 100" },
        ];

        // wait for the fonts to load
        // -- this should not be necessary if the fonts are installed as required
        // -- but if they are not, the test is otherwise unstable
        var once_fonts_are_ready = (document.fonts ? document.fonts.ready : new Promise(function(ready) { window.onload = time => [...document.querySelectorAll('body > span:nth-child(1) > span')].every(e => e.offsetWidth > 20) ? ready() : requestAnimationFrame(window.onload) }));

        var testcases = document.querySelector("#testcases");
        var testcaseTemplate = document.querySelector('.testcase'); testcaseTemplate.remove();
        testFontFaceMatch.forEach(function(element) {

            var testcase = testcaseTemplate.cloneNode(true);

            // setup the test case style
            testcase.style.fontFamily = 'fontMatch';
            testcase.style.fontWeight = element.weight;

            // create the assertion
            var assertText = 'A' + /\d/.exec(element.expectedFont)[0];
            testcase.textContent = assertText;

            // append the testcase
            testcases.appendChild(testcase);

            // verify the testcase
            promise_test(
                assert => once_fonts_are_ready.then(assert => { assert_approx_equals(testcase.getBoundingClientRect().width, 90, 2, "@font-face should be mapped to " + element.expectedFont + "."); }),
                "Test @font-face matching for weight " + element.weight
            );
        });

    </script>
</body>
</html>