import * as O from '.' ; describe ( 'prependTo' , ( ) => { type Source = string [ ] ; const source = [ 'foo' , 'bar' ] ; it ( 'set - monomorphic' , ( ) => { const result1 = O . set ( O . prependTo , 'abc' , source ) ; expect ( result1 ) . toEqual ( [ 'abc' , 'foo' , 'bar' ] ) ; } ) ; type Target = ( string | number ) [ ] ; it ( 'set - polymorphic' , ( ) => { const result1 = O . set ( O . prependTo , 42 , source ) ; expect ( result1 ) . toEqual ( [ 42 , 'foo' , 'bar' ] ) ; } ) ; } ) ;