Testing with UIKit and Angular

I have the following code in an angular component where declare const UIkit: any; is at the top of the file with the other imports.

When I run my tests with jest, I get the following error: ReferenceError: UIkit is not defined when the component is being created via the TestBed

Just wondering how I can point to the UIkit library during tests such that it doesn't fail.

declare const UIkit: any;

...

  ngOnInit() {
    UIkit.util.on('.sortables', 'moved', (item) => {
      // get order of blocks
      const blocks = Array.from(document.querySelectorAll('.sortable'));
      const newPositions = blocks.slice(0, blocks.length - 1).map(block => {
        return block.getAttribute('data-index');
      });

      // reorder document.blocks to match new order
      const newlyOrderedBlocks = [];
      newPositions.forEach(index => {
        newlyOrderedBlocks.push(this.document.blocks[index]);
      });
      this.document.blocks = newlyOrderedBlocks;
    });
  }