typedef (ArrayBuffer or ArrayBufferView) BinaryData;

dictionary FontFaceDescriptors {
    CSSOMString style = "normal";
    CSSOMString weight = "normal";
    CSSOMString stretch = "normal";
    CSSOMString unicodeRange = "U+0-10FFFF";
    CSSOMString featureSettings = "normal";
    CSSOMString variationSettings = "normal";
    CSSOMString display = "auto";
    CSSOMString ascentOverride = "normal";
    CSSOMString descentOverride = "normal";
    CSSOMString lineGapOverride = "normal";
};

enum FontFaceLoadStatus { "unloaded", "loading", "loaded", "error" };

// https://drafts.csswg.org/css-font-loading/#fontface-interface
[Exposed=(Window,Worker)]
interface FontFace {
    // FIXME: constructor(CSSOMString family, (CSSOMString or BinaryData) source, optional FontFaceDescriptors descriptors = {});
    constructor(CSSOMString family, CSSOMString source, optional FontFaceDescriptors descriptors = {});
    // FIXME: attribute CSSOMString family;
    // FIXME: attribute CSSOMString style;
    // FIXME: attribute CSSOMString weight;
    // FIXME: attribute CSSOMString stretch;
    // FIXME: attribute CSSOMString unicodeRange;
    // FIXME: attribute CSSOMString featureSettings;
    // FIXME: attribute CSSOMString variationSettings;
    // FIXME: attribute CSSOMString display;
    // FIXME: attribute CSSOMString ascentOverride;
    // FIXME: attribute CSSOMString descentOverride;
    // FIXME: attribute CSSOMString lineGapOverride;

    // FIXME: readonly attribute FontFaceLoadStatus status;

    Promise<FontFace> load();
    // FIXME: readonly attribute Promise<FontFace> loaded;
};