Function getComputedStyle

packages/sdk/src/adapters/iframe.test.ts:657–659

(_el: Element)

      // Supply our stub class so `candidate instanceof win.HTMLImageElement` works
      HTMLImageElement: FakeHTMLImageElement,
      getComputedStyle(_el: Element) {
        return { opacity: "1" } as CSSStyleDeclaration;
      },
    },
  } as unknown as HTMLIFrameElement;
}