in projects/libs/flex-layout/_private-utils/testing/dom-tools.ts [42:53]
function hasStyle(element: any,
styleName: string,
styleValue: string = '',
inlineOnly = true): boolean {
let value = getStyle(element, styleName) || '';
if (!value && !inlineOnly) {
// Search stylesheets
value = typeof getComputedStyle === 'function' &&
getComputedStyle(element).getPropertyValue(styleName) || '';
}
return styleValue ? value == styleValue : value.length > 0;
}