5 files changed, 235 insertions, 0 deletions
diff --git a/date-fns/src/sub/benchmark.js b/date-fns/src/sub/benchmark.js
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index 0000000..8b96341
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+++ b/date-fns/src/sub/benchmark.js
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+// @flow
+/* eslint-env mocha */
+/* global suite, benchmark */
+
+import sub from '.'
+import moment from 'moment'
+
+suite(
+  'add',
+  function() {
+    benchmark('date-fns', function() {
+      return sub(this.date, { hours: 5, minutes: 10 })
+    })
+
+    benchmark('Moment.js', function() {
+      return this.moment.subtract({ hours: 5, minutes: 10 })
+    })
+  },
+  {
+    setup: function() {
+      this.date = new Date()
+      this.moment = moment()
+    }
+  }
+)
diff --git a/date-fns/src/sub/index.d.ts b/date-fns/src/sub/index.d.ts
new file mode 100644
index 0000000..7a4f3ec
--- /dev/null
+++ b/date-fns/src/sub/index.d.ts
@@ -0,0 +1,4 @@
+// This file is generated automatically by `scripts/build/typings.js`. Please, don't change it.
+
+import { sub } from 'date-fns'
+export default sub
diff --git a/date-fns/src/sub/index.js b/date-fns/src/sub/index.js
new file mode 100644
index 0000000..fa5f30f
--- /dev/null
+++ b/date-fns/src/sub/index.js
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+import subDays from '../subDays/index'
+import subMonths from '../subMonths/index'
+import toDate from '../toDate/index'
+import requiredArgs from '../_lib/requiredArgs/index'
+import toInteger from '../_lib/toInteger/index'
+
+/**
+ * @name sub
+ * @category Common Helpers
+ * @summary Subtract the specified years, months, weeks, days, hours, minutes and seconds from the given date.
+ *
+ * @description
+ * Subtract the specified years, months, weeks, days, hours, minutes and seconds from the given date.
+ *
+ * @param {Date|Number} date - the date to be changed
+ * @param {Duration} duration - the object with years, months, weeks, days, hours, minutes and seconds to be subtracted
+ *
+ * | Key     | Description                        |
+ * |---------|------------------------------------|
+ * | years   | Amount of years to be subtracted   |
+ * | months  | Amount of months to be subtracted  |
+ * | weeks   | Amount of weeks to be subtracted   |
+ * | days    | Amount of days to be subtracted    |
+ * | hours   | Amount of hours to be subtracted   |
+ * | minutes | Amount of minutes to be subtracted |
+ * | seconds | Amount of seconds to be subtracted |
+ *
+ * All values default to 0
+ *
+ * @returns {Date} the new date with the seconds subtracted
+ * @throws {TypeError} 2 arguments required
+ *
+ * @example
+ * // Subtract the following duration from 15 June 2017 15:29:20
+ * const result = sub(new Date(2017, 5, 15, 15, 29, 20), {
+ *   years: 2,
+ *   months: 9,
+ *   weeks: 1,
+ *   days: 7,
+ *   hours: 5,
+ *   minutes: 9,
+ *   seconds: 30
+ * })
+ * //=> Mon Sep 1 2014 10:19:50
+ */
+export default function sub(dirtyDate, duration) {
+  requiredArgs(2, arguments)
+
+  if (!duration || typeof duration !== 'object') return new Date(NaN)
+
+  const years = 'years' in duration ? toInteger(duration.years) : 0
+  const months = 'months' in duration ? toInteger(duration.months) : 0
+  const weeks = 'weeks' in duration ? toInteger(duration.weeks) : 0
+  const days = 'days' in duration ? toInteger(duration.days) : 0
+  const hours = 'hours' in duration ? toInteger(duration.hours) : 0
+  const minutes = 'minutes' in duration ? toInteger(duration.minutes) : 0
+  const seconds = 'seconds' in duration ? toInteger(duration.seconds) : 0
+
+  // Subtract years and months
+  const dateWithoutMonths = subMonths(toDate(dirtyDate), months + years * 12)
+
+  // Subtract weeks and days
+  const dateWithoutDays = subDays(dateWithoutMonths, days + weeks * 7)
+
+  // Subtract hours, minutes and seconds
+  const minutestoSub = minutes + hours * 60
+  const secondstoSub = seconds + minutestoSub * 60
+  const mstoSub = secondstoSub * 1000
+  const finalDate = new Date(dateWithoutDays.getTime() - mstoSub)
+
+  return finalDate
+}
diff --git a/date-fns/src/sub/index.js.flow b/date-fns/src/sub/index.js.flow
new file mode 100644
index 0000000..e79df7c
--- /dev/null
+++ b/date-fns/src/sub/index.js.flow
@@ -0,0 +1,52 @@
+// @flow
+// This file is generated automatically by `scripts/build/typings.js`. Please, don't change it.
+
+export type Interval = {
+  start: Date | number,
+  end: Date | number,
+}
+
+export type Locale = {
+  code?: string,
+  formatDistance?: (...args: Array<any>) => any,
+  formatRelative?: (...args: Array<any>) => any,
+  localize?: {
+    ordinalNumber: (...args: Array<any>) => any,
+    era: (...args: Array<any>) => any,
+    quarter: (...args: Array<any>) => any,
+    month: (...args: Array<any>) => any,
+    day: (...args: Array<any>) => any,
+    dayPeriod: (...args: Array<any>) => any,
+  },
+  formatLong?: {
+    date: (...args: Array<any>) => any,
+    time: (...args: Array<any>) => any,
+    dateTime: (...args: Array<any>) => any,
+  },
+  match?: {
+    ordinalNumber: (...args: Array<any>) => any,
+    era: (...args: Array<any>) => any,
+    quarter: (...args: Array<any>) => any,
+    month: (...args: Array<any>) => any,
+    day: (...args: Array<any>) => any,
+    dayPeriod: (...args: Array<any>) => any,
+  },
+  options?: {
+    weekStartsOn?: 0 | 1 | 2 | 3 | 4 | 5 | 6,
+    firstWeekContainsDate?: 1 | 2 | 3 | 4 | 5 | 6 | 7,
+  },
+}
+
+export type Duration = {
+  years?: number,
+  months?: number,
+  weeks?: number,
+  days?: number,
+  hours?: number,
+  minutes?: number,
+  seconds?: number,
+}
+
+export type Day = 0 | 1 | 2 | 3 | 4 | 5 | 6
+
+declare module.exports: (date: Date | number, duration: Duration) => Date
diff --git a/date-fns/src/sub/test.js b/date-fns/src/sub/test.js
new file mode 100644
index 0000000..016accc
--- /dev/null
+++ b/date-fns/src/sub/test.js
@@ -0,0 +1,82 @@
+// @flow
+/* eslint-env mocha */
+
+import assert from 'power-assert'
+import sub from '.'
+
+describe('sub', () => {
+  it('subtracts the duration from the given date', () => {
+    const result = sub(new Date(2017, 5 /* June */, 15, 15, 29, 20), {
+      years: 2,
+      months: 9,
+      weeks: 1,
+      days: 7,
+      hours: 5,
+      minutes: 9,
+      seconds: 30
+    })
+    assert.deepEqual(result, new Date(2014, 8 /* Sep */, 1, 10, 19, 50))
+  })
+
+  it('returns same date object when passed empty duration', () => {
+    const result = sub(new Date(2014, 8 /* Sep */, 1, 10).getTime(), {})
+    assert.deepEqual(result, new Date(2014, 8 /* Sep */, 1, 10))
+  })
+
+  it('accepts a timestamp', () => {
+    const result = sub(new Date(2014, 8 /* Sep */, 1, 14).getTime(), {
+      hours: 4
+    })
+    assert.deepEqual(result, new Date(2014, 8 /* Sep */, 1, 10))
+  })
+
+  it('converts a fractional number to an integer', () => {
+    const result = sub(new Date(2014, 8 /* Sep */, 1, 14), { hours: 4.2 })
+    assert.deepEqual(result, new Date(2014, 8 /* Sep */, 1, 10))
+  })
+
+  it('implicitly converts number arguments', () => {
+    // $ExpectedMistake
+    const result = sub(new Date(2014, 8 /* Sep */, 1, 14), { hours: '4.2' })
+    assert.deepEqual(result, new Date(2014, 8 /* Sep */, 1, 10))
+  })
+
+  it('does not mutate the original date', () => {
+    const date = new Date(2014, 8 /* Sep */, 1, 10)
+    sub(date, { hours: 4 })
+    assert.deepEqual(date, new Date(2014, 8 /* Sep */, 1, 10))
+  })
+
+  it('works well if the desired month has fewer days and the provided date is in the last day of a month', () => {
+    const date = new Date(2014, 11 /* Dec */, 31)
+    const result = sub(date, { months: 3 })
+    assert.deepEqual(result, new Date(2014, 8 /* Sep */, 30))
+  })
+
+  it('handles dates before 100 AD', () => {
+    const initialDate = new Date(0)
+    initialDate.setFullYear(1, 2 /* Mar */, 31)
+    initialDate.setHours(0, 0, 0, 0)
+    const expectedResult = new Date(0)
+    expectedResult.setFullYear(1, 1 /* Feb */, 28)
+    expectedResult.setHours(0, 0, 0, 0)
+    const result = sub(initialDate, { months: 1 })
+    assert.deepEqual(result, expectedResult)
+  })
+
+  it('returns `Invalid Date` if the given date is invalid', () => {
+    const result = sub(new Date(NaN), { hours: 5 })
+    assert(result instanceof Date && isNaN(result))
+  })
+
+  it('throws RangeError exception if passed Number as duration', () => {
+    // $ExpectedMistake
+    const result = sub(new Date(2014, 8, 1), 'wut')
+    assert(result instanceof Date && isNaN(result))
+  })
+
+  it('throws TypeError exception if passed less than 2 arguments', () => {
+    assert.throws(sub.bind(null), TypeError)
+    assert.throws(sub.bind(null, 1), TypeError)
+  })
+})