message: tests: workaround perfectscroll importing issue in jest
diff: import * as React from 'react';
  -import { default as PerfectScrollbarConstructor } from 'perfect-scrollbar';
  +import PerfectScrollbarType, * as PerfectScrollbarNamespace from 'perfect-scrollbar';
  import psStyles from 'perfect-scrollbar/css/perfect-scrollbar.css';
  import styled, { injectGlobal } from '../styled-components';
  +/*
  + * perfect scrollbar umd bundle uses exports assignment while module uses default export
  + * so when bundled with webpack default export works but with jest it crashes
  + * That's why the following ugly fix is required
  + */
  +const PerfectScrollbarConstructor =
  + PerfectScrollbarNamespace.default || ((PerfectScrollbarNamespace as any) as PerfectScrollbarType);
  +
  injectGlobal`${psStyles && psStyles.toString()}`;
  const StyledScrollWrapper = styled.div`
  @@ -11,12 +19,12 @@ const StyledScrollWrapper = styled.div`
  `;
  export class PerfectScrollbar extends React.Component<{
  - options?: PerfectScrollbarConstructor.Options;
  + options?: PerfectScrollbarType.Options;
  className?: string;
  updateFn: (fn) => void;
  }> {
  private _container: HTMLElement;
  - private inst: PerfectScrollbarConstructor;
  + private inst: PerfectScrollbarType;
  componentDidMount() {
  this.inst = new PerfectScrollbarConstructor(this._container, this.props.options || {});
  