Function isLayerRule

src/inject/dynamic-theme/css-rules.ts:250–265

(rule: CSSRule | null)

}

export function isLayerRule(rule: CSSRule | null): rule is CSSLayerBlockRule {
    if (!rule) {
        return false;
    }
    if (styleRules.has(rule)) {
        return false;
    }
    if (layerRules.has(rule)) {
        return true;
    }
    if (isLayerRuleSupported && rule instanceof CSSLayerBlockRule) {
        layerRules.add(rule);
        return true;
    }
    return false;
}