The spreadMethod read-only property of the SVGGradientElement interface reflects the spreadMethod attribute of the given element. It takes one of the SVG_SPREADMETHOD_* constants defined on this interface.
spreadMethod property<svg xmlns="http://www.w3.org/2000/svg" width="200" height="200">
<defs>
<linearGradient id="gradient2" spreadMethod="reflect">
<stop offset="0%" stop-color="red" />
<stop offset="50%" stop-color="yellow" />
<stop offset="100%" stop-color="blue" />
</linearGradient>
</defs>
<rect x="10" y="10" width="180" height="180" fill="url(#gradient2)" />
</svg>const gradient = document.getElementById("gradient2");
console.log(gradient.spreadMethod.baseVal); // Output: 2 (SVG_SPREADMETHOD_REFLECT)