Make lower param of clamp required. [closes lodash#2949]

Author: jdalton

.internal/baseClamp.js

@@ -3,18 +3,14 @@
  *
  * @private
  * @param {number} number The number to clamp.
- * @param {number} [lower] The lower bound.
+ * @param {number} lower The lower bound.
  * @param {number} upper The upper bound.
  * @returns {number} Returns the clamped number.
  */
 function baseClamp(number, lower, upper) {
   if (number === number) {
-    if (upper !== undefined) {
-      number = number <= upper ? number : upper;
-    }
-    if (lower !== undefined) {
-      number = number >= lower ? number : lower;
-    }
+    number = number <= upper ? number : upper;
+    number = number >= lower ? number : lower;
   }
   return number;
 }

clamp.js

@@ -7,7 +7,7 @@ import toNumber from './toNumber.js';
  * @since 4.0.0
  * @category Number
  * @param {number} number The number to clamp.
- * @param {number} [lower] The lower bound.
+ * @param {number} lower The lower bound.
  * @param {number} upper The upper bound.
  * @returns {number} Returns the clamped number.
  * @example
@@ -19,18 +19,12 @@ import toNumber from './toNumber.js';
  * // => 5
  */
 function clamp(number, lower, upper) {
-  if (upper === undefined) {
-    upper = lower;
-    lower = undefined;
-  }
-  if (upper !== undefined) {
-    upper = toNumber(upper);
-    upper = upper === upper ? upper : 0;
-  }
-  if (lower !== undefined) {
-    lower = toNumber(lower);
-    lower = lower === lower ? lower : 0;
-  }
+  lower = toNumber(lower);
+  lower = lower === lower ? lower : 0;
+
+  upper = toNumber(upper);
+  upper = upper === upper ? upper : 0;
+
   return baseClamp(toNumber(number), lower, upper);
 }