add limit option to shuffleArray

1 files changed, 9 insertions, 3 deletions

diff --git a/general-util.js b/general-util.js
index bb0574a..b767a1b 100644
--- a/general-util.js
+++ b/general-util.js
@@ -78,7 +78,7 @@ export function downloadPlaylistFromOptionValue(arg) {
   }
 }
 
-export function shuffleArray(array) {
+export function shuffleArray(array, limit = array.length) {
   // Shuffles the items in an array. Returns a new array (does not modify the
   // passed array). Super-interesting post on how this algorithm works:
   // https://bost.ocks.org/mike/shuffle/
@@ -86,10 +86,12 @@ export function shuffleArray(array) {
   const workingArray = array.slice(0)
 
   let m = array.length
+  let n = limit
 
-  while (m) {
+  while (n) {
     let i = Math.floor(Math.random() * m)
     m--
+    n--
 
     // Stupid lol; avoids the need of a temporary variable!
     Object.assign(workingArray, {
@@ -98,7 +100,11 @@ export function shuffleArray(array) {
     })
   }
 
-  return workingArray
+  if (limit === array.length) {
+    return workingArray
+  } else {
+    return workingArray.slice(0, limit)
+  }
 }
 
 export function throttlePromise(maximumAtOneTime = 10) {