Migrate differenceInCalendarISOWeekYears function to TS (#2416)

src/differenceInCalendarISOWeekYears/index.js → src/differenceInCalendarISOWeekYears/index.ts

@@ -27,16 +27,16 @@ import requiredArgs from '../_lib/requiredArgs/index'
  *
  * @example
  * // How many calendar ISO week-numbering years are 1 January 2010 and 1 January 2012?
- * var result = differenceInCalendarISOWeekYears(
+ * const result = differenceInCalendarISOWeekYears(
  *   new Date(2012, 0, 1),
  *   new Date(2010, 0, 1)
  * )
  * //=> 2
  */
 export default function differenceInCalendarISOWeekYears(
-  dirtyDateLeft,
-  dirtyDateRight
-) {
+  dirtyDateLeft: Date | number,
+  dirtyDateRight: Date | number
+): number {
   requiredArgs(2, arguments)
 
   return getISOWeekYear(dirtyDateLeft) - getISOWeekYear(dirtyDateRight)

src/differenceInCalendarISOWeekYears/test.js → src/differenceInCalendarISOWeekYears/test.ts

@@ -1,115 +1,117 @@
-// @flow
 /* eslint-env mocha */
 
 import assert from 'power-assert'
 import differenceInCalendarISOWeekYears from '.'
 
-describe('differenceInCalendarISOWeekYears', function() {
-  it('returns the number of calendar ISO week-numbering years between the given dates', function() {
-    var result = differenceInCalendarISOWeekYears(
+describe('differenceInCalendarISOWeekYears', function () {
+  it('returns the number of calendar ISO week-numbering years between the given dates', function () {
+    const result = differenceInCalendarISOWeekYears(
       new Date(2012, 6 /* Jul */, 2, 18, 0),
       new Date(2011, 6 /* Jul */, 2, 6, 0)
     )
     assert(result === 1)
   })
 
-  it('returns a negative number if the time value of the first date is smaller', function() {
-    var result = differenceInCalendarISOWeekYears(
+  it('returns a negative number if the time value of the first date is smaller', function () {
+    const result = differenceInCalendarISOWeekYears(
       new Date(2011, 6 /* Jul */, 2, 6, 0),
       new Date(2012, 6 /* Jul */, 2, 18, 0)
     )
     assert(result === -1)
   })
 
-  it('accepts timestamps', function() {
-    var result = differenceInCalendarISOWeekYears(
+  it('accepts timestamps', function () {
+    const result = differenceInCalendarISOWeekYears(
       new Date(2014, 6 /* Jul */, 2).getTime(),
       new Date(2010, 6 /* Jul */, 2).getTime()
     )
     assert(result === 4)
   })
 
-  it('handles dates before 100 AD', function() {
-    var firstDate = new Date(0)
+  it('handles dates before 100 AD', function () {
+    const firstDate = new Date(0)
     firstDate.setFullYear(14, 0 /* Jan */, 1)
     firstDate.setHours(0, 0, 0, 0)
-    var secondDate = new Date(0)
+    const secondDate = new Date(0)
     secondDate.setFullYear(0, 0 /* Jan */, 1)
     secondDate.setHours(0, 0, 0, 0)
-    var result = differenceInCalendarISOWeekYears(firstDate, secondDate)
+    const result = differenceInCalendarISOWeekYears(firstDate, secondDate)
     assert(result === 15)
   })
 
-  describe('edge cases', function() {
-    it('the difference is less than an ISO year, but the given dates are in different calendar ISO years', function() {
-      var result = differenceInCalendarISOWeekYears(
+  describe('edge cases', function () {
+    it('the difference is less than an ISO year, but the given dates are in different calendar ISO years', function () {
+      const result = differenceInCalendarISOWeekYears(
         new Date(2012, 0 /* Jan */, 2),
         new Date(2012, 0 /* Jan */, 1)
       )
       assert(result === 1)
     })
 
-    it('the same for the swapped dates', function() {
-      var result = differenceInCalendarISOWeekYears(
+    it('the same for the swapped dates', function () {
+      const result = differenceInCalendarISOWeekYears(
         new Date(2012, 0 /* Jan */, 1),
         new Date(2012, 0 /* Jan */, 2)
       )
       assert(result === -1)
     })
 
-    it('the ISO weeks and weekdays of the given dates are the same', function() {
-      var result = differenceInCalendarISOWeekYears(
+    it('the ISO weeks and weekdays of the given dates are the same', function () {
+      const result = differenceInCalendarISOWeekYears(
         new Date(2013, 11 /* Dec */, 30),
         new Date(2012, 0 /* Jan */, 2)
       )
       assert(result === 2)
     })
 
-    it('the given dates are the same', function() {
-      var result = differenceInCalendarISOWeekYears(
+    it('the given dates are the same', function () {
+      const result = differenceInCalendarISOWeekYears(
         new Date(2014, 8 /* Sep */, 5, 0, 0),
         new Date(2014, 8 /* Sep */, 5, 0, 0)
       )
       assert(result === 0)
     })
 
     it('does not return -0 when the given dates are the same', () => {
-      function isNegativeZero(x) {
+      function isNegativeZero(x: number): boolean {
         return x === 0 && 1 / x < 0
       }
 
-      var result = differenceInCalendarISOWeekYears(
+      const result = differenceInCalendarISOWeekYears(
         new Date(2014, 8 /* Sep */, 5, 0, 0),
         new Date(2014, 8 /* Sep */, 5, 0, 0)
       )
 
-      var resultIsNegative = isNegativeZero(result)
+      const resultIsNegative = isNegativeZero(result)
       assert(resultIsNegative === false)
     })
   })
 
-  it('returns NaN if the first date is `Invalid Date`', function() {
-    var result = differenceInCalendarISOWeekYears(
+  it('returns NaN if the first date is `Invalid Date`', function () {
+    const result = differenceInCalendarISOWeekYears(
       new Date(NaN),
       new Date(2017, 0 /* Jan */, 1)
     )
     assert(isNaN(result))
   })
 
-  it('returns NaN if the second date is `Invalid Date`', function() {
-    var result = differenceInCalendarISOWeekYears(
+  it('returns NaN if the second date is `Invalid Date`', function () {
+    const result = differenceInCalendarISOWeekYears(
       new Date(2017, 0 /* Jan */, 1),
       new Date(NaN)
     )
     assert(isNaN(result))
   })
 
-  it('returns NaN if the both dates are `Invalid Date`', function() {
-    var result = differenceInCalendarISOWeekYears(new Date(NaN), new Date(NaN))
+  it('returns NaN if the both dates are `Invalid Date`', function () {
+    const result = differenceInCalendarISOWeekYears(
+      new Date(NaN),
+      new Date(NaN)
+    )
     assert(isNaN(result))
   })
 
-  it('throws TypeError exception if passed less than 2 arguments', function() {
+  it('throws TypeError exception if passed less than 2 arguments', function () {
     assert.throws(differenceInCalendarISOWeekYears.bind(null), TypeError)
     assert.throws(differenceInCalendarISOWeekYears.bind(null, 1), TypeError)
   })