4 files changed, 145 insertions, 0 deletions
diff --git a/date-fns/src/formatRFC7231/index.d.ts b/date-fns/src/formatRFC7231/index.d.ts
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+// This file is generated automatically by `scripts/build/typings.js`. Please, don't change it.
+
+import { formatRFC7231 } from 'date-fns'
+export default formatRFC7231
diff --git a/date-fns/src/formatRFC7231/index.js b/date-fns/src/formatRFC7231/index.js
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+import toDate from '../toDate/index'
+import isValid from '../isValid/index'
+import addLeadingZeros from '../_lib/addLeadingZeros/index'
+
+const days = ['Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat']
+const months = [
+  'Jan',
+  'Feb',
+  'Mar',
+  'Apr',
+  'May',
+  'Jun',
+  'Jul',
+  'Aug',
+  'Sep',
+  'Oct',
+  'Nov',
+  'Dec'
+]
+
+/**
+ * @name formatRFC7231
+ * @category Common Helpers
+ * @summary Format the date according to the RFC 7231 standard (https://tools.ietf.org/html/rfc7231#section-7.1.1.1).
+ *
+ * @description
+ * Return the formatted date string in RFC 7231 format.
+ * The result will always be in UTC timezone.
+ *
+ * @param {Date|Number} date - the original date
+ * @returns {String} the formatted date string
+ * @throws {TypeError} 1 argument required
+ * @throws {RangeError} `date` must not be Invalid Date
+ *
+ * @example
+ * // Represent 18 September 2019 in RFC 7231 format:
+ * const result = formatRFC7231(new Date(2019, 8, 18, 19, 0, 52))
+ * //=> 'Wed, 18 Sep 2019 19:00:52 GMT'
+ */
+export default function formatRFC7231(dirtyDate) {
+  if (arguments.length < 1) {
+    throw new TypeError(
+      `1 arguments required, but only ${arguments.length} present`
+    )
+  }
+
+  const originalDate = toDate(dirtyDate)
+
+  if (!isValid(originalDate)) {
+    throw new RangeError('Invalid time value')
+  }
+
+  const dayName = days[originalDate.getUTCDay()]
+  const dayOfMonth = addLeadingZeros(originalDate.getUTCDate(), 2)
+  const monthName = months[originalDate.getUTCMonth()]
+  const year = originalDate.getUTCFullYear()
+
+  const hour = addLeadingZeros(originalDate.getUTCHours(), 2)
+  const minute = addLeadingZeros(originalDate.getUTCMinutes(), 2)
+  const second = addLeadingZeros(originalDate.getUTCSeconds(), 2)
+
+  // Result variables.
+  return `${dayName}, ${dayOfMonth} ${monthName} ${year} ${hour}:${minute}:${second} GMT`
+}
diff --git a/date-fns/src/formatRFC7231/index.js.flow b/date-fns/src/formatRFC7231/index.js.flow
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+++ b/date-fns/src/formatRFC7231/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: (date: Date | number) => string
diff --git a/date-fns/src/formatRFC7231/test.js b/date-fns/src/formatRFC7231/test.js
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+++ b/date-fns/src/formatRFC7231/test.js
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+// @flow
+/* eslint-env mocha */
+
+import assert from 'power-assert'
+import formatRFC7231 from '.'
+
+describe('formatRFC7231', () => {
+  it('formats RFC-7231 date string', () => {
+    const date = new Date(Date.UTC(2019, 2, 3, 19, 0, 52))
+    assert(formatRFC7231(date) === 'Sun, 03 Mar 2019 19:00:52 GMT')
+  })
+
+  it('accepts a timestamp', () => {
+    const date = Date.UTC(2019, 9, 4, 12, 30, 13)
+    assert(formatRFC7231(date) === 'Fri, 04 Oct 2019 12:30:13 GMT')
+  })
+
+  it('throws RangeError if the time value is invalid', () => {
+    assert.throws(formatRFC7231.bind(null, new Date(NaN)), RangeError)
+  })
+
+  it('throws TypeError exception if passed less than 1 argument', function() {
+    assert.throws(formatRFC7231.bind(null), TypeError)
+  })
+})