From 6f00a1303e7173383512584bc3787eb75ee006d9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jakob=20Segersl=C3=A4tt?= <segerslatt@gmail.com>
Date: Fri, 22 Feb 2019 13:34:35 +0100
Subject: [PATCH] Added optional parameter to getRandomEntry

---
 src/array-utils.ts       | 18 ++++++++++++++++--
 test/array-utils.spec.ts |  7 +++++++
 2 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/src/array-utils.ts b/src/array-utils.ts
index 96a0ae5..faf3625 100644
--- a/src/array-utils.ts
+++ b/src/array-utils.ts
@@ -22,9 +22,23 @@ export function flattenTree<T = object>(array: T[] = [], key: string | ((s: T) =
  * Based on Math.random()
  * @param array The array of which you want a random entry
  */
-export function getRandomEntry<T>(array: T[]): T {
+export function getRandomEntry<T>(array: T[], arrayToPopulate?: T[], tryCount?: number): T {
     const randomIndex = Math.floor(Math.random() * array.length);
-    return array[randomIndex];
+    const randomEntry = array[randomIndex];
+
+    /**
+     * If arrayToPopulate is provided; run this method again.
+     * Repeat until the maxium amount of tries has been done
+     * so we avoid getting stuck in an infinite loop
+     * (which could happen if @param array only has a single entry)
+     */
+    tryCount = tryCount || 5;
+    if (tryCount > 0 && arrayToPopulate && arrayToPopulate.includes(randomEntry)) {
+        tryCount--;
+        return getRandomEntry(array, arrayToPopulate);
+    }
+
+    return randomEntry;
 }
 
 /**
diff --git a/test/array-utils.spec.ts b/test/array-utils.spec.ts
index beae446..e57e3f4 100644
--- a/test/array-utils.spec.ts
+++ b/test/array-utils.spec.ts
@@ -89,6 +89,13 @@ describe('getRandomEntry() test', () => {
         const bar = getRandomEntry([]);
         expect(bar).to.equal(undefined);
     });
+
+    it('should return the first entry for an array of 1', () => {
+        const source = [{ foo: 'foo' }];
+        const arrayToPopulate = [{ foo: 'foo' }];
+        const bar = getRandomEntry(source, arrayToPopulate);
+        expect(bar).to.eql({ foo: 'foo' });
+    });
 });
 
 describe('groupArrayByProperty() test', () => {