feat: date filters from Jekyll

src/filters/date.ts

@@ -1,13 +1,46 @@
 import { toValue, stringify, isString, isNumber, TimezoneDate, LiquidDate, strftime, isNil } from '../util'
 import { FilterImpl } from '../template'
+import { LiquidOptions } from '../liquid-options'
 
 export function date (this: FilterImpl, v: string | Date, format?: string, timezoneOffset?: number | string) {
-  const opts = this.context.opts
+  const date = parseDate(v, this.context.opts, timezoneOffset)
+  if (!date) return v
+  format = toValue(format)
+  format = isNil(format) ? this.context.opts.dateFormat : stringify(format)
+  return strftime(date, format)
+}
+
+export function date_to_xmlschema (this: FilterImpl, v: string | Date) {
+  return date.call(this, v, '%Y-%m-%dT%H:%M:%S%:z')
+}
+
+export function date_to_rfc822 (this: FilterImpl, v: string | Date) {
+  return date.call(this, v, '%a, %d %b %Y %H:%M:%S %z')
+}
+
+export function date_to_string (this: FilterImpl, v: string | Date, type?: string, style?: string) {
+  return stringify_date.call(this, v, '%b', type, style)
+}
+
+export function date_to_long_string (this: FilterImpl, v: string | Date, type?: string, style?: string) {
+  return stringify_date.call(this, v, '%B', type, style)
+}
+
+function stringify_date (this: FilterImpl, v: string | Date, month_type: string, type?: string, style?: string) {
+  const date = parseDate(v, this.context.opts)
+  if (!date) return v
+  if (type === 'ordinal') {
+    const d = date.getDate()
+    return style === 'US'
+      ? strftime(date, `${month_type} ${d}%q, %Y`)
+      : strftime(date, `${d}%q ${month_type} %Y`)
+  }
+  return strftime(date, `%d ${month_type} %Y`)
+}
+
+function parseDate (v: string | Date, opts: LiquidOptions, timezoneOffset?: number | string): LiquidDate | undefined {
   let date: LiquidDate
   v = toValue(v)
-  format = toValue(format)
-  if (isNil(format)) format = opts.dateFormat
-  else format = stringify(format)
   if (v === 'now' || v === 'today') {
     date = new Date()
   } else if (isNumber(v)) {
@@ -23,13 +56,13 @@ export function date (this: FilterImpl, v: string | Date, format?: string, timez
   } else {
     date = v
   }
-  if (!isValidDate(date)) return v
+  if (!isValidDate(date)) return
   if (timezoneOffset !== undefined) {
     date = new TimezoneDate(date, timezoneOffset)
   } else if (!(date instanceof TimezoneDate) && opts.timezoneOffset !== undefined) {
     date = new TimezoneDate(date, opts.timezoneOffset)
   }
-  return strftime(date, format)
+  return date
 }
 
 function isValidDate (date: any): date is Date {

src/util/strftime.ts

@@ -45,31 +45,16 @@ function isLeapYear (d: LiquidDate) {
   const year = d.getFullYear()
   return !!((year & 3) === 0 && (year % 100 || (year % 400 === 0 && year)))
 }
-function getSuffix (d: LiquidDate) {
+function ordinal (d: LiquidDate) {
   const date = d.getDate()
+  if ([11, 12, 13].includes(date)) return 'th'
 
-  let suffix = 'th'
-
-  switch (date) {
-    case 11:
-    case 12:
-    case 13:
-      break
-    default:
-      switch (date % 10) {
-        case 1:
-          suffix = 'st'
-          break
-        case 2:
-          suffix = 'nd'
-          break
-        case 3:
-          suffix = 'rd'
-          break
-      }
+  switch (date % 10) {
+    case 1: return 'st'
+    case 2: return 'nd'
+    case 3: return 'rd'
+    default: return 'th'
   }
-
-  return suffix
 }
 function century (d: LiquidDate) {
   return parseInt(d.getFullYear().toString().substring(0, 2), 10)
@@ -138,7 +123,7 @@ const formatCodes = {
   },
   p: (d: LiquidDate) => (d.getHours() < 12 ? 'AM' : 'PM'),
   P: (d: LiquidDate) => (d.getHours() < 12 ? 'am' : 'pm'),
-  q: (d: LiquidDate) => getSuffix(d),
+  q: (d: LiquidDate) => ordinal(d),
   s: (d: LiquidDate) => Math.round(d.getTime() / 1000),
   S: (d: LiquidDate) => d.getSeconds(),
   u: (d: LiquidDate) => d.getDay() || 7,