import assert from 'assert' ; import differenceInCalendarWeeks from '.' ; describe ( 'differenceInCalendarWeeks' , ( ) => { it ( 'returns the number of calendar weeks between the given dates' , ( ) => { const result = differenceInCalendarWeeks ( new Date ( 2014 , 6 , 8 , 18 , 0 ) , new Date ( 2014 , 5 , 29 , 6 , 0 ) ) ; assert ( result === 1 ) ; } ) ; it ( 'allows to specify which day is the first day of the week' , ( ) => { const result = differenceInCalendarWeeks ( new Date ( 2014 , 6 , 8 , 18 , 0 ) , new Date ( 2014 , 5 , 29 , 6 , 0 ) , { weekStartsOn : 1 } ) ; assert ( result === 2 ) ; } ) ; it ( 'allows to specify which day is the first day of the week in locale' , ( ) => { const result = differenceInCalendarWeeks ( new Date ( 2014 , 6 , 8 , 18 , 0 ) , new Date ( 2014 , 5 , 29 , 6 , 0 ) , { locale : { options : { weekStartsOn : 1 } , } , } ) ; assert ( result === 2 ) ; } ) ; it ( '`options.weekStartsOn` overwrites the first day of the week specified in locale' , ( ) => { const result = differenceInCalendarWeeks ( new Date ( 2014 , 6 , 8 , 18 , 0 ) , new Date ( 2014 , 5 , 29 , 6 , 0 ) , { weekStartsOn : 1 , locale : { options : { weekStartsOn : 0 } , } , } ) ; assert ( result === 2 ) ; } ) ; it ( 'returns a positive number if the time value of the second date is smaller' , ( ) => { const result = differenceInCalendarWeeks ( new Date ( 2014 , 6 , 8 , 18 , 0 ) , new Date ( 2014 , 5 , 29 , 6 , 0 ) , { weekStartsOn : '1' , } ) ; assert ( result === 2 ) ; } ) ; it ( 'returns a negative number if the time value of the first date is smaller' , ( ) => { const result = differenceInCalendarWeeks ( new Date ( 2014 , 5 , 29 , 6 , 0 ) , new Date ( 2014 , 6 , 8 , 18 , 0 ) ) ; assert ( result === - 1 ) ; } ) ; it ( 'accepts timestamps' , ( ) => { const result = differenceInCalendarWeeks ( new Date ( 2014 , 6 , 12 ) . getTime ( ) , new Date ( 2014 , 6 , 2 ) . getTime ( ) ) ; assert ( result === 1 ) ; } ) ; describe ( 'edge cases' , ( ) => { it ( 'the difference is less than a week, but the given dates are in different calendar weeks' , ( ) => { const result = differenceInCalendarWeeks ( new Date ( 2014 , 6 , 6 ) , new Date ( 2014 , 6 , 5 ) ) ; assert ( result === 1 ) ; } ) ; it ( 'the same for the swapped dates' , ( ) => { const result = differenceInCalendarWeeks ( new Date ( 2014 , 6 , 5 ) , new Date ( 2014 , 6 , 6 ) ) ; assert ( result === - 1 ) ; } ) ; it ( 'the days of weeks of the given dates are the same' , ( ) => { const result = differenceInCalendarWeeks ( new Date ( 2014 , 6 , 9 ) , new Date ( 2014 , 6 , 2 ) ) ; assert ( result === 1 ) ; } ) ; it ( 'the given dates are the same' , ( ) => { const result = differenceInCalendarWeeks ( new Date ( 2014 , 8 , 5 , 0 , 0 ) , new Date ( 2014 , 8 , 5 , 0 , 0 ) ) ; assert ( result === 0 ) ; } ) ; it ( 'does not return -0 when the given dates are the same' , ( ) => { function isNegativeZero ( x ) { return x === 0 && 1 / x < 0 ; } const result = differenceInCalendarWeeks ( new Date ( 2014 , 8 , 5 , 0 , 0 ) , new Date ( 2014 , 8 , 5 , 0 , 0 ) ) ; const resultIsNegative = isNegativeZero ( result ) ; assert ( resultIsNegative === false ) ; } ) ; } ) ; it ( 'returns NaN if the first date is `Invalid Date`' , ( ) => { const result = differenceInCalendarWeeks ( new Date ( NaN ) , new Date ( 2017 , 0 , 1 ) ) ; assert ( isNaN ( result ) ) ; } ) ; it ( 'returns NaN if the second date is `Invalid Date`' , ( ) => { const result = differenceInCalendarWeeks ( new Date ( 2017 , 0 , 1 ) , new Date ( NaN ) ) ; assert ( isNaN ( result ) ) ; } ) ; it ( 'returns NaN if the both dates are `Invalid Date`' , ( ) => { const result = differenceInCalendarWeeks ( new Date ( NaN ) , new Date ( NaN ) ) ; assert ( isNaN ( result ) ) ; } ) ; it ( 'throws `RangeError` if `options.weekStartsOn` is not convertable to 0, 1, ..., 6 or undefined' , ( ) => { const block = ( ) => differenceInCalendarWeeks ( new Date ( 2014 , 6 , 8 , 18 , 0 ) , new Date ( 2014 , 5 , 29 , 6 , 0 ) , { weekStartsOn : NaN , } ) ; assert . throws ( block , RangeError ) ; } ) ; it ( 'throws TypeError exception if passed less than 2 arguments' , ( ) => { assert . throws ( differenceInCalendarWeeks . bind ( null ) , TypeError ) ; assert . throws ( differenceInCalendarWeeks . bind ( null , 1 ) , TypeError ) ; } ) ; } ) ;