let animation: boolean; function isCssAnimationSupported() { if (animation !== undefined) { return animation; } const domPrefixes = 'Webkit Moz O ms Khtml'.split(' '); const elm = document.createElement('div'); if (elm.style.animationName !== undefined) { animation = true; } if (animation !== undefined) { for (let i = 0; i < domPrefixes.length; i++) { if ((elm.style as any)[`${domPrefixes[i]}AnimationName`] !== undefined) { animation = true; break; } } } animation = animation || false; return animation; } export default isCssAnimationSupported;