static computeTimeGrid()

in resources/perf.webkit.org/public/v3/components/time-series-chart.js [621:672]
41 lines of code
14 McCabe index (conditional complexity)

    static computeTimeGrid(min, max, maxLabels)
    {
        const diffPerLabel = (max - min) / maxLabels;

        let iterator;
        for (iterator of this._timeIterators()) {
            if (iterator.diff >= diffPerLabel)
                break;
        }
        console.assert(iterator);

        const currentTime = new Date(min);
        currentTime.setUTCMilliseconds(0);
        currentTime.setUTCSeconds(0);
        currentTime.setUTCMinutes(0);
        iterator.next(currentTime);

        const fitsInOneDay = max - min < 24 * 3600 * 1000;

        let result = [];

        let previousDate = null;
        let previousMonth = null;
        while (currentTime <= max && result.length < maxLabels) {
            const time = new Date(currentTime);
            const month = time.getUTCMonth() + 1;
            const date = time.getUTCDate();
            const hour = time.getUTCHours();
            const hourLabel = ((hour % 12) || 12) + (hour >= 12 ? 'PM' : 'AM');

            iterator.next(currentTime);

            let label;
            const isMidnight = !hour;
            if ((date == previousDate && month == previousMonth) || ((!isMidnight || previousDate == null) && fitsInOneDay))
                label = hourLabel;
            else {
                label = `${month}/${date}`;
                if (!isMidnight && currentTime.getUTCDate() != date)
                    label += ' ' + hourLabel;
            }

            result.push({time: time, label: label});

            previousDate = date;
            previousMonth = month;
        }

        console.assert(result.length <= maxLabels);

        return result;
    }