Merge branch '10097-number-utils' into 'master'

Moves EE differences out of number_utils.js

Closes gitlab-ee#10097

See merge request gitlab-org/gitlab-ce!25680

app/assets/javascripts/lib/utils/number_utils.js

@@ -80,3 +80,22 @@ export function numberToHumanSize(size) {
   }
   return `${bytesToGiB(size).toFixed(2)} GiB`;
 }
+
+/**
+ * A simple method that returns the value of a + b
+ * It seems unessesary, but when combined with a reducer it
+ * adds up all the values in an array.
+ *
+ * e.g. `[1, 2, 3, 4, 5].reduce(sum) // => 15`
+ *
+ * @param {Float} a
+ * @param {Float} b
+ * @example
+ * // return 15
+ * [1, 2, 3, 4, 5].reduce(sum);
+ *
+ * // returns 6
+ * Object.values([{a: 1, b: 2, c: 3].reduce(sum);
+ * @returns {Float} The summed value
+ */
+export const sum = (a = 0, b = 0) => a + b;

changelogs/unreleased/10097-number-utils.yml

+---
+title: Moves EE util into the CE file
+merge_request: 25680
+author:
+type: other

spec/javascripts/lib/utils/number_utility_spec.js

@@ -4,6 +4,7 @@ import {
   bytesToMiB,
   bytesToGiB,
   numberToHumanSize,
+  sum,
 } from '~/lib/utils/number_utils';
 
 describe('Number Utils', () => {
@@ -87,4 +88,14 @@ describe('Number Utils', () => {
       expect(numberToHumanSize(10737418240)).toEqual('10.00 GiB');
     });
   });
+
+  describe('sum', () => {
+    it('should add up two values', () => {
+      expect(sum(1, 2)).toEqual(3);
+    });
+
+    it('should add up all the values in an array when passed to a reducer', () => {
+      expect([1, 2, 3, 4, 5].reduce(sum)).toEqual(15);
+    });
+  });
 });