Simplify shuffle and sample.

sampleSize.js

@@ -1,15 +1,13 @@
-import arraySampleSize from './.internal/arraySampleSize.js'
-import baseSampleSize from './.internal/baseSampleSize.js'
 import isIterateeCall from './.internal/isIterateeCall.js'
 import toInteger from './toInteger.js'
 
 /**
- * Gets `n` random elements at unique keys from `collection` up to the
- * size of `collection`.
+ * Gets `n` random elements at unique keys from `array` up to the
+ * size of `array`.
  *
  * @since 4.0.0
- * @category Collection
- * @param {Array|Object} collection The collection to sample.
+ * @category Array
+ * @param {Array} array The array to sample.
  * @param {number} [n=1] The number of elements to sample.
  * @param- {Object} [guard] Enables use as an iteratee for methods like `map`.
  * @returns {Array} Returns the random elements.
@@ -21,14 +19,27 @@ import toInteger from './toInteger.js'
  * sampleSize([1, 2, 3], 4)
  * // => [2, 3, 1]
  */
-function sampleSize(collection, n, guard) {
+function sampleSize(array, n, guard) {
   if ((guard ? isIterateeCall(collection, n, guard) : n === undefined)) {
     n = 1
   } else {
     n = toInteger(n)
   }
-  const func = Array.isArray(collection) ? arraySampleSize : baseSampleSize
-  return func(collection, n)
+  const length = array == null ? 0 : array.length
+  if (!length || n < 1) {
+    return []
+  }
+  n = n > length ? length : n
+  let index = -1
+  const lastIndex = n - 1
+  const result = copyArray(array)
+  while (++index < n) {
+    const rand = index + Math.floor(Math.random() * (lastIndex - index + 1))
+    const value = result[rand]
+    result[rand] = result[index]
+    result[index] = value
+  }
+  return result
 }
 
 export default sampleSize