From b937d0c7c9ad1dff0aac8e9ba50268026baf67ca Mon Sep 17 00:00:00 2001
From: Taeuk Kang <mail@taeuk.me>
Date: Thu, 19 Jul 2018 09:46:19 +0900
Subject: [PATCH] Implemented fromMillis() to verify args (#301)

Made fromMillis() verify its arg is a number
---
 src/datetime.js              | 14 +++++++++-----
 test/datetime/create.test.js |  4 ++++
 2 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/src/datetime.js b/src/datetime.js
index 2520ebfaa..e7e604b25 100644
--- a/src/datetime.js
+++ b/src/datetime.js
@@ -501,11 +501,15 @@ export default class DateTime {
    * @return {DateTime}
    */
   static fromMillis(milliseconds, options = {}) {
-    return new DateTime({
-      ts: milliseconds,
-      zone: normalizeZone(options.zone, Settings.defaultZone),
-      loc: Locale.fromObject(options)
-    });
+    if (!isNumber(milliseconds)) {
+      throw new InvalidArgumentError('fromMillis requires a numerical input');
+    } else {
+      return new DateTime({
+        ts: milliseconds,
+        zone: normalizeZone(options.zone, Settings.defaultZone),
+        loc: Locale.fromObject(options)
+      });
+    }
   }
 
   /**
diff --git a/test/datetime/create.test.js b/test/datetime/create.test.js
index 8885cba34..4f2187b67 100644
--- a/test/datetime/create.test.js
+++ b/test/datetime/create.test.js
@@ -256,6 +256,10 @@ test('DateTime.fromMillis accepts the default locale', () => {
   withDefaultLocale('fr', () => expect(DateTime.fromMillis(391147200000).locale).toBe('fr'));
 });
 
+test('DateTime.fromMillis(ms) throws InvalidArgumentError for non-numeric input', () => {
+  expect(() => DateTime.fromMillis('slurp')).toThrow();
+});
+
 //------
 // .fromObject()
 //-------