Remove arrayPush in favor of spreading arguments.

.internal/arrayPush.js

@@ -1,20 +0,0 @@
-/**
- * Appends the elements of `values` to `array`.
- *
- * @private
- * @param {Array} array The array to modify.
- * @param {Array} values The values to append.
- * @returns {Array} Returns `array`.
- */
-function arrayPush(array, values) {
-  let index = -1
-  const length = values.length
-  const offset = array.length
-
-  while (++index < length) {
-    array[offset + index] = values[index]
-  }
-  return array
-}
-
-export default arrayPush

.internal/baseFlatten.js

@@ -1,4 +1,3 @@
-import arrayPush from './arrayPush.js'
 import isFlattenable from './isFlattenable.js'
 
 /**
@@ -26,7 +25,7 @@ function baseFlatten(array, depth, predicate, isStrict, result) {
         // Recursively flatten arrays (susceptible to call stack limits).
         baseFlatten(value, depth - 1, predicate, isStrict, result)
       } else {
-        arrayPush(result, value)
+        result.push(...value)
       }
     } else if (!isStrict) {
       result[result.length] = value

.internal/getAllKeys.js

@@ -1,4 +1,3 @@
-import arrayPush from './arrayPush.js'
 import getSymbols from './getSymbols.js'
 import keys from '../keys.js'
 
@@ -11,7 +10,10 @@ import keys from '../keys.js'
  */
 function getAllKeys(object) {
   const result = keys(object)
-  return Array.isArray(object) ? result : arrayPush(result, getSymbols(object))
+  if (!Array.isArray(object)) {
+    result.push(...getSymbols(object))
+  }
+  return result
 }
 
 export default getAllKeys

.internal/getAllKeysIn.js

@@ -1,10 +1,8 @@
-import arrayPush from './arrayPush.js'
 import getSymbolsIn from './getSymbolsIn.js'
 import keysIn from '../keysIn.js'
 
 /**
- * Creates an array of own and inherited enumerable property names and
+ * Creates an array of own and inherited enumerable property names and symbols of `object`.
- * symbols of `object`.
  *
  * @private
  * @param {Object} object The object to query.
@@ -12,7 +10,10 @@ import keysIn from '../keysIn.js'
  */
 function getAllKeysIn(object) {
   const result = keysIn(object)
-  return Array.isArray(object) ? result : arrayPush(result, getSymbolsIn(object))
+  if (!Array.isArray(object)) {
+    result.push(...getSymbolsIn(object))
+  }
+  return result
 }
 
 export default getAllKeysIn

.internal/getSymbolsIn.js

@@ -1,4 +1,3 @@
-import arrayPush from './arrayPush.js'
 import getSymbols from './getSymbols.js'
 
 /* Built-in method references for those with the same name as other `lodash` methods. */
@@ -14,7 +13,7 @@ const nativeGetSymbols = Object.getOwnPropertySymbols
 const getSymbolsIn = !nativeGetSymbols ? () => [] : object => {
   const result = []
   while (object) {
-    arrayPush(result, getSymbols(object))
+    result.push(...getSymbols(object))
     object = Object.getPrototypeOf(Object(object))
   }
   return result