5 files changed, 284 insertions, 0 deletions
diff --git a/date-fns/src/eachHourOfInterval/benchmark.js b/date-fns/src/eachHourOfInterval/benchmark.js
new file mode 100644
index 0000000..c96c557
--- /dev/null
+++ b/date-fns/src/eachHourOfInterval/benchmark.js
@@ -0,0 +1,20 @@
+// @flow
+/* eslint-env mocha */
+/* global suite, benchmark */
+
+import eachHourOfInterval from '.'
+
+suite(
+  'eachHourOfInterval',
+  function() {
+    benchmark('date-fns', function() {
+      return eachHourOfInterval({ start: this.dateA, end: this.dateB })
+    })
+  },
+  {
+    setup: function() {
+      this.dateA = new Date()
+      this.dateB = new Date(this.dateA.getTime() + 604800000)
+    }
+  }
+)
diff --git a/date-fns/src/eachHourOfInterval/index.d.ts b/date-fns/src/eachHourOfInterval/index.d.ts
new file mode 100644
index 0000000..4c3addd
--- /dev/null
+++ b/date-fns/src/eachHourOfInterval/index.d.ts
@@ -0,0 +1,4 @@
+// This file is generated automatically by `scripts/build/typings.js`. Please, don't change it.
+
+import { eachHourOfInterval } from 'date-fns'
+export default eachHourOfInterval
diff --git a/date-fns/src/eachHourOfInterval/index.js.flow b/date-fns/src/eachHourOfInterval/index.js.flow
new file mode 100644
index 0000000..5a9b8e4
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+++ b/date-fns/src/eachHourOfInterval/index.js.flow
@@ -0,0 +1,57 @@
+// @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: (
+  interval: Interval,
+  options?: {
+    step?: number,
+  }
+) => Date[]
diff --git a/date-fns/src/eachHourOfInterval/index.ts b/date-fns/src/eachHourOfInterval/index.ts
new file mode 100644
index 0000000..27ad6dc
--- /dev/null
+++ b/date-fns/src/eachHourOfInterval/index.ts
@@ -0,0 +1,69 @@
+import addHours from '../addHours/index'
+import toDate from '../toDate/index'
+import requiredArgs from '../_lib/requiredArgs/index'
+import { Interval, StepOptions } from '../types'
+
+/**
+ * @name eachHourOfInterval
+ * @category Interval Helpers
+ * @summary Return the array of hours within the specified time interval.
+ *
+ * @description
+ * Return the array of hours within the specified time interval.
+ *
+ * @param {Interval} interval - the interval. See [Interval]{@link https://date-fns.org/docs/Interval}
+ * @param {Object} [options] - an object with options.
+ * @param {Number} [options.step=1] - the step to increment by. The value should be more than 1.
+ * @returns {Date[]} the array with starts of hours from the hour of the interval start to the hour of the interval end
+ * @throws {TypeError} 1 argument required
+ * @throws {RangeError} `options.step` must be a number greater than 1
+ * @throws {RangeError} The start of an interval cannot be after its end
+ * @throws {RangeError} Date in interval cannot be `Invalid Date`
+ *
+ * @example
+ * // Each hour between 6 October 2014, 12:00 and 6 October 2014, 15:00
+ * var result = eachHourOfInterval({
+ *   start: new Date(2014, 9, 6, 12),
+ *   end: new Date(2014, 9, 6, 15)
+ * })
+ * //=> [
+ * //   Mon Oct 06 2014 12:00:00,
+ * //   Mon Oct 06 2014 13:00:00,
+ * //   Mon Oct 06 2014 14:00:00,
+ * //   Mon Oct 06 2014 15:00:00
+ * // ]
+ */
+export default function eachHourOfInterval(
+  dirtyInterval: Interval,
+  options?: StepOptions
+): Date[] {
+  requiredArgs(1, arguments)
+
+  const interval = dirtyInterval || {}
+  const startDate = toDate(interval.start)
+  const endDate = toDate(interval.end)
+
+  const startTime = startDate.getTime()
+  const endTime = endDate.getTime()
+
+  // Throw an exception if start date is after end date or if any date is `Invalid Date`
+  if (!(startTime <= endTime)) {
+    throw new RangeError('Invalid interval')
+  }
+
+  const dates = []
+
+  let currentDate = startDate
+  currentDate.setMinutes(0, 0, 0)
+
+  const step = options && 'step' in options ? Number(options.step) : 1
+  if (step < 1 || isNaN(step))
+    throw new RangeError('`options.step` must be a number greater than 1')
+
+  while (currentDate.getTime() <= endTime) {
+    dates.push(toDate(currentDate))
+    currentDate = addHours(currentDate, step)
+  }
+
+  return dates
+}
diff --git a/date-fns/src/eachHourOfInterval/test.ts b/date-fns/src/eachHourOfInterval/test.ts
new file mode 100644
index 0000000..4bdaa05
--- /dev/null
+++ b/date-fns/src/eachHourOfInterval/test.ts
@@ -0,0 +1,134 @@
+// @flow
+/* eslint-env mocha */
+
+import assert from 'assert'
+import eachHourOfInterval from '.'
+
+describe('eachHourOfInterval', () => {
+  it('returns an array with starts of hours from the hour of the start date to the hour of the end date', () => {
+    const result = eachHourOfInterval({
+      start: new Date(2014, 9 /* Oct */, 6, 12),
+      end: new Date(2014, 9 /* Oct */, 6, 15)
+    })
+    assert.deepEqual(result, [
+      new Date(2014, 9 /* Oct */, 6, 12),
+      new Date(2014, 9 /* Oct */, 6, 13),
+      new Date(2014, 9 /* Oct */, 6, 14),
+      new Date(2014, 9 /* Oct */, 6, 15)
+    ])
+  })
+
+  it('accepts timestamps', () => {
+    const result = eachHourOfInterval({
+      start: new Date(2014, 9 /* Oct */, 6, 12).getTime(),
+      end: new Date(2014, 9 /* Oct */, 6, 15).getTime()
+    })
+    assert.deepEqual(result, [
+      new Date(2014, 9 /* Oct */, 6, 12),
+      new Date(2014, 9 /* Oct */, 6, 13),
+      new Date(2014, 9 /* Oct */, 6, 14),
+      new Date(2014, 9 /* Oct */, 6, 15)
+    ])
+  })
+
+  it('handles the hours that are not starts of hours', () => {
+    const result = eachHourOfInterval({
+      start: new Date(2014, 9 /* Oct */, 6, 12, 59, 59, 999),
+      end: new Date(2014, 9 /* Oct */, 6, 15, 59, 59, 999)
+    })
+    assert.deepEqual(result, [
+      new Date(2014, 9 /* Oct */, 6, 12),
+      new Date(2014, 9 /* Oct */, 6, 13),
+      new Date(2014, 9 /* Oct */, 6, 14),
+      new Date(2014, 9 /* Oct */, 6, 15)
+    ])
+  })
+
+  it('returns one hour if the both arguments are on the same hour', () => {
+    const result = eachHourOfInterval({
+      start: new Date(2014, 9 /* Oct */, 6, 12, 35),
+      end: new Date(2014, 9 /* Oct */, 6, 12, 47)
+    })
+    assert.deepEqual(result, [new Date(2014, 9 /* Oct */, 6, 12)])
+  })
+
+  it('returns one hour if the both arguments are the same', () => {
+    const result = eachHourOfInterval({
+      start: new Date(2014, 9 /* Oct */, 6, 12, 35),
+      end: new Date(2014, 9 /* Oct */, 6, 12, 35)
+    })
+    assert.deepEqual(result, [new Date(2014, 9 /* Oct */, 6, 12)])
+  })
+
+  it('throws an exception if the start date is after the end date', () => {
+    const block = eachHourOfInterval.bind(null, {
+      start: new Date(2014, 9 /* Oct */, 12, 35, 0, 0, 1),
+      end: new Date(2014, 9 /* Oct */, 12, 35, 0, 0, 0)
+    })
+    assert.throws(block, RangeError)
+  })
+
+  it('throws an exception if the start date is `Invalid Date`', () => {
+    const block = eachHourOfInterval.bind(null, {
+      start: new Date(NaN),
+      end: new Date(2014, 9 /* Oct */, 6, 12)
+    })
+    assert.throws(block, RangeError)
+  })
+
+  it('throws an exception if the end date is `Invalid Date`', () => {
+    const block = eachHourOfInterval.bind(null, {
+      start: new Date(2014, 9 /* Oct */, 12, 12),
+      end: new Date(NaN)
+    })
+    assert.throws(block, RangeError)
+  })
+
+  it('throws an exception if the interval is undefined', () => {
+    const block = eachHourOfInterval.bind(
+      null,
+      // $ExpectedMistake
+      undefined
+    )
+    assert.throws(block, RangeError)
+  })
+
+  it('throws TypeError exception if passed less than 1 argument', () => {
+    assert.throws(eachHourOfInterval.bind(null), TypeError)
+  })
+
+  describe('options.step', () => {
+    const interval = {
+      start: new Date(2014, 9 /* Oct */, 6, 12),
+      end: new Date(2014, 9 /* Oct */, 6, 18)
+    }
+
+    const stepError = /^RangeError: `options.step` must be a number greater than 1$/
+
+    it('returns an array with starts of hours from the hour of the start date to the hour of the end date with the given step', () => {
+      const result = eachHourOfInterval(interval, { step: 3 })
+      assert.deepEqual(result, [
+        new Date(2014, 9 /* Oct */, 6, 12),
+        new Date(2014, 9 /* Oct */, 6, 15),
+        new Date(2014, 9 /* Oct */, 6, 18)
+      ])
+    })
+
+    it('throws TypeError error if `options.step` is less than 1', () => {
+      assert.throws(() => eachHourOfInterval(interval, { step: 0 }), stepError)
+      assert.throws(() => eachHourOfInterval(interval, { step: -3 }), stepError)
+    })
+
+    it('throws TypeError error if `options.step` is NaN', () => {
+      // $ExpectedMistake
+      assert.throws(
+        () => eachHourOfInterval(interval, { step: 'w' }),
+        stepError
+      )
+      assert.throws(
+        () => eachHourOfInterval(interval, { step: NaN }),
+        stepError
+      )
+    })
+  })
+})