Function assertElementNodes

packages/core/src/animation/utils.ts:56–63

(nativeElement: Element, instruction: string)

 * Asserts a given native element is an actual Element node and not something like a comment node.
 */
export function assertElementNodes(nativeElement: Element, instruction: string) {
  if ((nativeElement as Node).nodeType !== Node.ELEMENT_NODE) {
    throw new RuntimeError(
      RuntimeErrorCode.ANIMATE_INVALID_VALUE,
      `'${instruction}' can only be used on an element node, got ${stringify((nativeElement as Node).nodeType)}`,
    );
  }
}

/**
 * trackEnterClasses is necessary in the case of composition where animate.enter