summaryrefslogtreecommitdiff
path: root/date-fns/src/differenceInCalendarISOWeekYears/test.ts
blob: db38e288ac178652898cf6a06b98063dc0e27b77 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
/* 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 () {
    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 () {
    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 () {
    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 () {
    const firstDate = new Date(0)
    firstDate.setFullYear(14, 0 /* Jan */, 1)
    firstDate.setHours(0, 0, 0, 0)
    const secondDate = new Date(0)
    secondDate.setFullYear(0, 0 /* Jan */, 1)
    secondDate.setHours(0, 0, 0, 0)
    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 () {
      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 () {
      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 () {
      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 () {
      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: number): boolean {
        return x === 0 && 1 / x < 0
      }

      const result = differenceInCalendarISOWeekYears(
        new Date(2014, 8 /* Sep */, 5, 0, 0),
        new Date(2014, 8 /* Sep */, 5, 0, 0)
      )

      const resultIsNegative = isNegativeZero(result)
      assert(resultIsNegative === false)
    })
  })

  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 () {
    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 () {
    const result = differenceInCalendarISOWeekYears(
      new Date(NaN),
      new Date(NaN)
    )
    assert(isNaN(result))
  })

  it('throws TypeError exception if passed less than 2 arguments', function () {
    assert.throws(differenceInCalendarISOWeekYears.bind(null), TypeError)
    assert.throws(differenceInCalendarISOWeekYears.bind(null, 1), TypeError)
  })
})