css/css-paint-api/registered-properties-in-custom-paint.https.html

<!DOCTYPE html>
<html class="reftest-wait">
<link rel="match" href="parse-input-arguments-ref.html">
<style>
.container {
  width: 100px;
  height: 100px;
  --length: 10px;
  --number: 10;
}

#canvas-geometry {
  background-image: paint(geometry);
}
</style>
<script src="/common/reftest-wait.js"></script>
<script src="/common/css-paint-tests.js"></script>
<body>
<div id="canvas-geometry" class="container"></div>

<script id="code" type="text/worklet">
registerPaint('geometry', class {
    static get inputProperties() {
        return [
            '--length',
            '--length-initial',
            '--number',
        ];
    }
    paint(ctx, geom, styleMap) {
        const properties = styleMap.getProperties().sort();
        var serializedStrings = [];
        for (let i = 0; i < properties.length; i++) {
            const value = styleMap.get(properties[i]);
            let serialized;
            if (value)
                serialized = properties[i].toString() + ': [' + value.constructor.name + '=' + value.toString() + ']';
            else
                serialized = properties[i].toString() + ': [null]';
            serializedStrings.push(serialized);
        }
        ctx.strokeStyle = 'green';
        if (serializedStrings[0] != "--length: [CSSUnitValue=10px]")
            ctx.strokeStyle = 'red';
        if (serializedStrings[1] != "--length-initial: [CSSUnitValue=20px]")
            ctx.strokeStyle = 'blue';
        if (serializedStrings[2] != "--number: [CSSStyleValue=10]")
            ctx.strokeStyle = 'yellow';
        ctx.lineWidth = 4;
        ctx.strokeRect(0, 0, geom.width, geom.height);
    }
});
</script>

<script>
    CSS.registerProperty({name: '--length', syntax: '<length>', initialValue: '0px'});
    CSS.registerProperty({name: '--length-initial', syntax: '<length>', initialValue: '20px'});
    CSS.registerProperty({name: '--number', syntax: '<number>', initialValue: '0'});
    importPaintWorkletAndTerminateTestAfterAsyncPaint(document.getElementById('code').textContent);
</script>
</body>
</html>