import { chartsReducer } from './charts.reducer' ; import { chartsInitialState } from './charts.state' ; describe ( 'Charts Reducer' , ( ) => { describe ( 'an unknown action' , ( ) => { it ( 'should return the previous state' , ( ) => { const action = { } as any ; const result = chartsReducer ( chartsInitialState , action ) ; expect ( result ) . toBe ( chartsInitialState ) ; } ) ; } ) ; } ) ;