检测日期间隔之间差异的功能/ES6方法？

Question

I have a function that I am using to try and determine if a set of date segments meets a criteria.

I am using date-fns' distanceInDays function to return an integer value of the distance between the previous segment's end date and the current segment's start date.

(current.startDate - previous.endDate)

Problem is that the reduce function is giving me type errors.

type DateSegment = {startDate: string, endDate: string} // ISO 8601 timestamps


const isValid = (current: ResidentialAddress, history: Array<ResidentialAddress>): boolean => {
    if (!current || history.length === 0) return false;

    const currentDate = formatInTimeZone(new Date(), 'UTC', 'yyyy-MM-dd');
    // Convert current residence and residential history to segments.
    const segments: DateSegment[] = [
        { startDate: current.startDate, endDate: currentDate },
        ...history.map(x => ({ startDate: x.startDate, endDate: x.endDate }))
    ];
    // Sort them
    const sorted = segments.sort((a, b) => isSameOrBefore(a.startDate, b.startDate));

    const result = sorted.reduce((previousValue, currentValue) =>
        differenceInDays(new Date(currentValue.startDate), new Date(previousValue.endDate))),
        {endDate: currentDate}
    );
    console.log(result);
    return true;
};

NB: The current residence does not have an end date, so the current date is provided to it.

Answer 1

This will return an array of distances between intervals.

const distances = array.map((item, index: number) => {
    if (!array[index-1]) return
    return item.start - array[index-1].end
    }
)