update Array#flatMap per tc39/proposal-flatMap#50

zloirock · May 5, 2018 · e78d4a1 · e78d4a1
1 parent 1253d70
commit e78d4a1
Showing 1 changed file with 2 additions and 2 deletions.
diff --git a/modules/esnext.array.flat-map.js b/modules/esnext.array.flat-map.js
@@ -10,9 +10,9 @@ var arraySpeciesCreate = require('./_array-species-create');
 $export($export.P, 'Array', {
   flatMap: function flatMap(callbackfn /* , thisArg */) {
     var O = toObject(this);
-    var sourceLen, A;
+    var sourceLen = toLength(O.length);
+    var A;
     aFunction(callbackfn);
-    sourceLen = toLength(O.length);
     A = arraySpeciesCreate(O, 0);
     A.length = flattenIntoArray(A, O, O, sourceLen, 0, 1, callbackfn, arguments[1]);
     return A;