fix: Fix bug in customParseFormat plugin while month(MM) is '01'

fix #494

Author: iamkun

src/plugin/customParseFormat/index.js

@@ -129,7 +129,7 @@ const parseFormattedInput = (input, format) => {
     }
     const now = new Date()
     return new Date(
-      year || now.getFullYear(), month - 1 || now.getMonth(), day || now.getDate(),
+      year || now.getFullYear(), month > 0 ? month - 1 : now.getMonth(), day || now.getDate(),
       hours || 0, minutes || 0, seconds || 0, milliseconds || 0
     )
   } catch (e) {

test/plugin/customParseFormat.test.js

@@ -24,6 +24,12 @@ it('parse padded string', () => {
   expect(dayjs(input, format).valueOf()).toBe(moment(input, format).valueOf())
 })
 
+it('parse string January (getMonth() = 0)', () => {
+  const input = '01/01/2019'
+  const format = 'DD/MM/YYYY'
+  expect(dayjs(input, format).valueOf()).toBe(moment(input, format).valueOf())
+})
+
 it('parse unpadded string', () => {
   const input = '2.5.18 1:2:3.4 PM -0100'
   const format = 'D.M.YY H:m:s.S A ZZ'