forked from dachan/dach
1
0
Fork 0
dach/node_modules/postgres-date/index.js

117 lines
2.6 KiB
JavaScript

'use strict'
var DATE_TIME = /(\d{1,})-(\d{2})-(\d{2}) (\d{2}):(\d{2}):(\d{2})(\.\d{1,})?.*?( BC)?$/
var DATE = /^(\d{1,})-(\d{2})-(\d{2})( BC)?$/
var TIME_ZONE = /([Z+-])(\d{2})?:?(\d{2})?:?(\d{2})?/
var INFINITY = /^-?infinity$/
module.exports = function parseDate (isoDate) {
if (INFINITY.test(isoDate)) {
// Capitalize to Infinity before passing to Number
return Number(isoDate.replace('i', 'I'))
}
var matches = DATE_TIME.exec(isoDate)
if (!matches) {
// Force YYYY-MM-DD dates to be parsed as local time
return getDate(isoDate) || null
}
var isBC = !!matches[8]
var year = parseInt(matches[1], 10)
if (isBC) {
year = bcYearToNegativeYear(year)
}
var month = parseInt(matches[2], 10) - 1
var day = matches[3]
var hour = parseInt(matches[4], 10)
var minute = parseInt(matches[5], 10)
var second = parseInt(matches[6], 10)
var ms = matches[7]
ms = ms ? 1000 * parseFloat(ms) : 0
var date
var offset = timeZoneOffset(isoDate)
if (offset != null) {
date = new Date(Date.UTC(year, month, day, hour, minute, second, ms))
// Account for years from 0 to 99 being interpreted as 1900-1999
// by Date.UTC / the multi-argument form of the Date constructor
if (is0To99(year)) {
date.setUTCFullYear(year)
}
if (offset !== 0) {
date.setTime(date.getTime() - offset)
}
} else {
date = new Date(year, month, day, hour, minute, second, ms)
if (is0To99(year)) {
date.setFullYear(year)
}
}
return date
}
function getDate (isoDate) {
var matches = DATE.exec(isoDate)
if (!matches) {
return
}
var year = parseInt(matches[1], 10)
var isBC = !!matches[4]
if (isBC) {
year = bcYearToNegativeYear(year)
}
var month = parseInt(matches[2], 10) - 1
var day = matches[3]
// YYYY-MM-DD will be parsed as local time
var date = new Date(year, month, day)
if (is0To99(year)) {
date.setFullYear(year)
}
return date
}
// match timezones:
// Z (UTC)
// -05
// +06:30
function timeZoneOffset (isoDate) {
if (isoDate.endsWith('+00')) {
return 0
}
var zone = TIME_ZONE.exec(isoDate.split(' ')[1])
if (!zone) return
var type = zone[1]
if (type === 'Z') {
return 0
}
var sign = type === '-' ? -1 : 1
var offset = parseInt(zone[2], 10) * 3600 +
parseInt(zone[3] || 0, 10) * 60 +
parseInt(zone[4] || 0, 10)
return offset * sign * 1000
}
function bcYearToNegativeYear (year) {
// Account for numerical difference between representations of BC years
// See: https://github.com/bendrucker/postgres-date/issues/5
return -(year - 1)
}
function is0To99 (num) {
return num >= 0 && num < 100
}