refactor: add and use parseDate

Conversions/DateDayDifference.js

@@ -7,6 +7,7 @@
 */
 
 import { isLeapYear } from '../Maths/LeapYear'
+import { parseDate } from '../Timing-Functions/ParseDate'
 
 const DateToDay = (dd, mm, yyyy) => {
   return (
@@ -20,32 +21,13 @@ const DateToDay = (dd, mm, yyyy) => {
   )
 }
 
-const CheckDayAndMonth = (inDay, inMonth) => {
-  if (inDay <= 0 || inDay > 31 || inMonth <= 0 || inMonth > 12) {
-    throw new TypeError('Date is not valid.')
-  }
-}
-
 const DateDayDifference = (date1, date2) => {
-  // firstly, check that both input are string or not.
-  if (typeof date1 !== 'string' || typeof date2 !== 'string') {
-    throw new TypeError('Argument is not a string.')
-  }
-  // extract the first date
-  const [firstDateDay, firstDateMonth, firstDateYear] = date1
-    .split('/')
-    .map((ele) => Number(ele))
-  // extract the second date
-  const [secondDateDay, secondDateMonth, secondDateYear] = date2
-    .split('/')
-    .map((ele) => Number(ele))
-  // check the both data are valid or not.
-  CheckDayAndMonth(firstDateDay, firstDateMonth)
-  CheckDayAndMonth(secondDateDay, secondDateMonth)
+  const firstDate = parseDate(date1)
+  const secondDate = parseDate(date2)
 
   return Math.abs(
-    DateToDay(secondDateDay, secondDateMonth, secondDateYear) -
-      DateToDay(firstDateDay, firstDateMonth, firstDateYear)
+    DateToDay(secondDate.day, secondDate.month, secondDate.year) -
+      DateToDay(firstDate.day, firstDate.month, firstDate.year)
   )
 }
 

Conversions/DateToDay.js

@@ -12,6 +12,8 @@
     Algorithm & Explanation : https://en.wikipedia.org/wiki/Zeller%27s_congruence
 */
 
+import { parseDate } from '../Timing-Functions/ParseDate'
+
 // Array holding name of the day: Saturday - Sunday - Friday => 0 - 1 - 6
 const daysNameArr = [
   'Saturday',
@@ -25,15 +27,10 @@ const daysNameArr = [
 
 const DateToDay = (date) => {
   // firstly, check that input is a string or not.
-  if (typeof date !== 'string') {
-    throw new TypeError('Argument is not a string.')
-  }
-  // extract the date
-  let [day, month, year] = date.split('/').map((x) => Number(x))
-  // check the data are valid or not.
-  if (day < 1 || day > 31 || month > 12 || month < 1) {
-    throw new TypeError('Date is not valid.')
-  }
+  const dateStruct = parseDate(date)
+  let year = dateStruct.year
+  let month = dateStruct.month
+  let day = dateStruct.day
 
   // In case of Jan and Feb:
   // Year: we consider it as previous year

Timing-Functions/ParseDate.js

@@ -0,0 +1,27 @@
+import { getMonthDays } from './GetMonthDays'
+
+function checkDate(date) {
+  if (date.day < 1 || date.day > getMonthDays(date.month, date.year)) {
+    throw new Error('Invalid day value.')
+  }
+}
+
+function parseDate(dateString) {
+  const regex = /^(\d{1,2})\/(\d{1,2})\/(\d{4})$/
+
+  const match = dateString.match(regex)
+
+  if (!match) {
+    throw new Error("Invalid date format. Please use 'dd/mm/yyyy'.")
+  }
+
+  const res = {
+    day: parseInt(match[1], 10),
+    month: parseInt(match[2], 10),
+    year: parseInt(match[3], 10)
+  }
+  checkDate(res)
+  return res
+}
+
+export { parseDate }

Timing-Functions/test/ParseDate.test.js

@@ -0,0 +1,40 @@
+import { parseDate } from '../ParseDate'
+
+describe('parseDate', () => {
+  it.each([
+    ['18/03/2024', { year: 2024, month: 3, day: 18 }],
+    ['29/02/2024', { year: 2024, month: 2, day: 29 }],
+    ['28/02/2023', { year: 2023, month: 2, day: 28 }],
+    ['01/12/2024', { year: 2024, month: 12, day: 1 }],
+    ['1/12/2024', { year: 2024, month: 12, day: 1 }],
+    ['10/1/2024', { year: 2024, month: 1, day: 10 }]
+  ])('Returns correct output for %s', (dateString, expected) => {
+    expect(parseDate(dateString)).toStrictEqual(expected)
+  })
+
+  it.each([
+    '18-03-2024',
+    '18.03.2024',
+    '03/2024',
+    '01/02/03/2024',
+    '123/03/2024'
+  ])('Throws for %s', (wrongDateString) => {
+    expect(() => {
+      parseDate(wrongDateString)
+    }).toThrow()
+  })
+
+  it.each([
+    '40/03/2024',
+    '30/02/2024',
+    '29/02/2023',
+    '31/04/2023',
+    '00/01/2024',
+    '01/00/2024',
+    '01/13/2024'
+  ])('Throws for %s', (wrongDateString) => {
+    expect(() => {
+      parseDate(wrongDateString)
+    }).toThrow()
+  })
+})