4 files changed, 102 insertions, 0 deletions
diff --git a/date-fns/src/yearsToMonths/index.d.ts b/date-fns/src/yearsToMonths/index.d.ts
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index 0000000..9e9126d
--- /dev/null
+++ b/date-fns/src/yearsToMonths/index.d.ts
@@ -0,0 +1,4 @@
+// This file is generated automatically by `scripts/build/typings.js`. Please, don't change it.
+
+import { yearsToMonths } from 'date-fns'
+export default yearsToMonths
diff --git a/date-fns/src/yearsToMonths/index.js.flow b/date-fns/src/yearsToMonths/index.js.flow
new file mode 100644
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+++ b/date-fns/src/yearsToMonths/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: (years: number) => number
diff --git a/date-fns/src/yearsToMonths/index.ts b/date-fns/src/yearsToMonths/index.ts
new file mode 100644
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+++ b/date-fns/src/yearsToMonths/index.ts
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+import requiredArgs from '../_lib/requiredArgs/index'
+import { monthsInYear } from '../constants/index'
+
+/**
+ * @name yearsToMonths
+ * @category Conversion Helpers
+ * @summary Convert years to months.
+ *
+ * @description
+ * Convert a number of years to a full number of months.
+ *
+ * @param {number} years - number of years to be converted
+ *
+ * @returns {number} the number of years converted in months
+ * @throws {TypeError} 1 argument required
+ *
+ * @example
+ * // Convert 2 years into months
+ * const result = yearsToMonths(2)
+ * //=> 24
+ */
+export default function yearsToMonths(years: number): number {
+  requiredArgs(1, arguments)
+  return Math.floor(years * monthsInYear)
+}
diff --git a/date-fns/src/yearsToMonths/test.ts b/date-fns/src/yearsToMonths/test.ts
new file mode 100644
index 0000000..e91231c
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+++ b/date-fns/src/yearsToMonths/test.ts
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+/* eslint-env mocha */
+
+import assert from 'assert'
+import yearsToMonths from '.'
+
+describe('yearsToMonths', function () {
+  it('converts years to months', function () {
+    assert(yearsToMonths(1) === 12)
+    assert(yearsToMonths(2) === 24)
+  })
+
+  it('uses floor rounding', () => {
+    assert(yearsToMonths(1.7) === 20)
+    assert(yearsToMonths(0.1) === 1)
+  })
+
+  it('handles border values', () => {
+    assert(yearsToMonths(1.5) === 18)
+    assert(yearsToMonths(0) === 0)
+  })
+})