jest . mock ( "react-transition-group" , ( ) => ( { CSSTransition : ( props ) => props . children , Transition : ( props ) => props . children , TransitionGroup : ( props ) => props . children , } ) ) ; jest . mock ( "react-dom" , ( ) => ( { ... ( jest . requireActual ( "react-dom" ) as any ) , createPortal : ( node ) => node , } ) ) ; jest . mock ( "popper.js" , ( ) => { const PopperJS = jest . requireActual ( "popper.js" ) ; return class Popper { public static placements = PopperJS . placements ; constructor ( ) { return { destroy : ( ) => { } , scheduleUpdate : ( ) => { } , } ; } } ; } ) ;