5 files changed, 191 insertions, 0 deletions
diff --git a/date-fns/src/differenceInMilliseconds/benchmark.js b/date-fns/src/differenceInMilliseconds/benchmark.js
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index 0000000..ab4d05a
--- /dev/null
+++ b/date-fns/src/differenceInMilliseconds/benchmark.js
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+// @flow
+/* eslint-env mocha */
+/* global suite, benchmark */
+
+import differenceInMilliseconds from '.'
+import moment from 'moment'
+
+suite('differenceInMilliseconds', function () {
+  benchmark('date-fns', function () {
+    return differenceInMilliseconds(this.dateA, this.dateB)
+  })
+
+  benchmark('Moment.js', function () {
+    return this.momentA.diff(this.momentB)
+  })
+}, {
+  setup: function () {
+    this.dateA = new Date()
+    this.momentA = moment()
+    this.dateB = new Date(this.dateA.getTime() + 604800000)
+    this.momentB = this.momentA.clone().add(7, 'days')
+  }
+})
diff --git a/date-fns/src/differenceInMilliseconds/index.d.ts b/date-fns/src/differenceInMilliseconds/index.d.ts
new file mode 100644
index 0000000..c72a3ab
--- /dev/null
+++ b/date-fns/src/differenceInMilliseconds/index.d.ts
@@ -0,0 +1,4 @@
+// This file is generated automatically by `scripts/build/typings.js`. Please, don't change it.
+
+import { differenceInMilliseconds } from 'date-fns'
+export default differenceInMilliseconds
diff --git a/date-fns/src/differenceInMilliseconds/index.js.flow b/date-fns/src/differenceInMilliseconds/index.js.flow
new file mode 100644
index 0000000..c799819
--- /dev/null
+++ b/date-fns/src/differenceInMilliseconds/index.js.flow
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+// @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: (
+  dateLeft: Date | number,
+  dateRight: Date | number
+) => number
diff --git a/date-fns/src/differenceInMilliseconds/index.ts b/date-fns/src/differenceInMilliseconds/index.ts
new file mode 100644
index 0000000..a0fc552
--- /dev/null
+++ b/date-fns/src/differenceInMilliseconds/index.ts
@@ -0,0 +1,39 @@
+import toDate from '../toDate/index'
+import requiredArgs from '../_lib/requiredArgs/index'
+
+/**
+ * @name differenceInMilliseconds
+ * @category Millisecond Helpers
+ * @summary Get the number of milliseconds between the given dates.
+ *
+ * @description
+ * Get the number of milliseconds between the given dates.
+ *
+ * ### v2.0.0 breaking changes:
+ *
+ * - [Changes that are common for the whole library](https://github.com/date-fns/date-fns/blob/master/docs/upgradeGuide.md#Common-Changes).
+ *
+ * @param {Date|Number} dateLeft - the later date
+ * @param {Date|Number} dateRight - the earlier date
+ * @returns {Number} the number of milliseconds
+ * @throws {TypeError} 2 arguments required
+ *
+ * @example
+ * // How many milliseconds are between
+ * // 2 July 2014 12:30:20.600 and 2 July 2014 12:30:21.700?
+ * const result = differenceInMilliseconds(
+ *   new Date(2014, 6, 2, 12, 30, 21, 700),
+ *   new Date(2014, 6, 2, 12, 30, 20, 600)
+ * )
+ * //=> 1100
+ */
+export default function differenceInMilliseconds(
+  dirtyDateLeft: Date | number,
+  dirtyDateRight: Date | number
+): number {
+  requiredArgs(2, arguments)
+
+  const dateLeft = toDate(dirtyDateLeft)
+  const dateRight = toDate(dirtyDateRight)
+  return dateLeft.getTime() - dateRight.getTime()
+}
diff --git a/date-fns/src/differenceInMilliseconds/test.ts b/date-fns/src/differenceInMilliseconds/test.ts
new file mode 100644
index 0000000..366c03b
--- /dev/null
+++ b/date-fns/src/differenceInMilliseconds/test.ts
@@ -0,0 +1,70 @@
+/* eslint-env mocha */
+
+import assert from 'power-assert'
+import differenceInMilliseconds from '.'
+
+describe('differenceInMilliseconds', function () {
+  it('returns the number of milliseconds between the given dates', function () {
+    const result = differenceInMilliseconds(
+      new Date(2014, 6 /* Jul */, 2, 12, 30, 20, 700),
+      new Date(2014, 6 /* Jul */, 2, 12, 30, 20, 600)
+    )
+    assert(result === 100)
+  })
+
+  it('returns a negative number if the time value of the first date is smaller', function () {
+    const result = differenceInMilliseconds(
+      new Date(2014, 6 /* Jul */, 2, 12, 30, 20, 600),
+      new Date(2014, 6 /* Jul */, 2, 12, 30, 20, 700)
+    )
+    assert(result === -100)
+  })
+
+  it('accepts timestamps', function () {
+    const result = differenceInMilliseconds(
+      new Date(2014, 8 /* Sep */, 5, 18, 30, 45, 500).getTime(),
+      new Date(2014, 8 /* Sep */, 5, 18, 30, 45, 500).getTime()
+    )
+    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 = differenceInMilliseconds(
+      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 = differenceInMilliseconds(
+      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 = differenceInMilliseconds(
+      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 = differenceInMilliseconds(new Date(NaN), new Date(NaN))
+    assert(isNaN(result))
+  })
+
+  it('throws TypeError exception if passed less than 2 arguments', function () {
+    assert.throws(differenceInMilliseconds.bind(null), TypeError)
+    assert.throws(differenceInMilliseconds.bind(null, 1), TypeError)
+  })
+})