fix: CustomParseFormat plugin parse Do format string

fix #522

src/plugin/customParseFormat/index.js

@@ -1,4 +1,4 @@
-const formattingTokens = /(\[[^[]*\])|([-:/.()\s]+)|(A|a|YYYY|YY?|MM?M?M?|DD?|hh?|HH?|mm?|ss?|S{1,3}|z|ZZ?)/g
+const formattingTokens = /(\[[^[]*\])|([-:/.()\s]+)|(A|a|YYYY|YY?|MM?M?M?|Do|DD?|hh?|HH?|mm?|ss?|S{1,3}|z|ZZ?)/g
 
 const match1 = /\d/ // 0 - 9
 const match2 = /\d\d/ // 00 - 99
@@ -56,6 +56,16 @@ const expressions = {
   hh: [match1to2, addInput('hours')],
   D: [match1to2, addInput('day')],
   DD: [match2, addInput('day')],
+  Do: [matchWord, function (input) {
+    const { ordinal } = locale;
+    [this.day] = input.match(/\d+/)
+    if (!ordinal) return
+    for (let i = 1; i <= 31; i += 1) {
+      if (ordinal(i).replace(/\[|\]/g, '') === input) {
+        this.day = i
+      }
+    }
+  }],
   M: [match1to2, addInput('month')],
   MM: [match2, addInput('month')],
   MMM: [matchWord, function (input) {

test/plugin/customParseFormat.test.js

@@ -3,6 +3,7 @@ import moment from 'moment'
 import dayjs from '../../src'
 import customParseFormat from '../../src/plugin/customParseFormat'
 import uk from '../../src/locale/uk'
+import '../../src/locale/zh-cn'
 
 dayjs.extend(customParseFormat)
 
@@ -169,3 +170,19 @@ it('correctly parse month from string after changing locale globally', () => {
     moment.locale(momentLocale)
   }
 })
+
+it('correctly parse ordinal', () => {
+  const input = '7th March 2019'
+  const input2 = '17th March 2019'
+  const inputFalse = '7st March 2019'
+  const inputZHCN = '7日 三月 2019'
+  const format = 'Do MMMM YYYY'
+  expect(dayjs(input, format).valueOf())
+    .toBe(moment(input, format).valueOf())
+  expect(dayjs(input2, format).valueOf())
+    .toBe(moment(input2, format).valueOf())
+  expect(dayjs(inputFalse, format).valueOf())
+    .toBe(moment(inputFalse, format).valueOf())
+  expect(dayjs(inputZHCN, format, 'zh-cn').valueOf())
+    .toBe(moment(inputZHCN, format, 'zh-cn').valueOf())
+})