From 8ac1d54858233e5fd8a6543e63a39ebb9b3fd527 Mon Sep 17 00:00:00 2001
From: John-David Dalton <john.david.dalton@gmail.com>
Date: Sat, 5 Mar 2016 16:56:59 -0800
Subject: [PATCH] Add fast path for numbers in `_.toNumber`.

---
 lodash.js    |  3 +++
 test/test.js | 14 ++++++++++++++
 2 files changed, 17 insertions(+)

diff --git a/lodash.js b/lodash.js
index 6db75064d..8a8c133dd 100644
--- a/lodash.js
+++ b/lodash.js
@@ -11022,6 +11022,9 @@
      * // => 3
      */
     function toNumber(value) {
+      if (typeof value == 'number') {
+        return value;
+      }
       if (isSymbol(value)) {
         return NAN;
       }
diff --git a/test/test.js b/test/test.js
index e1c920d0a..f1cff6122 100644
--- a/test/test.js
+++ b/test/test.js
@@ -21872,6 +21872,20 @@
       return '+' + string;
     }
 
+    QUnit.test('`_.' + methodName + '` should pass thru primitive number values', function(assert) {
+      assert.expect(1);
+
+      var values = [0, 1, NaN];
+
+      var expected = lodashStable.map(values, function(value) {
+        return (!isToNumber && value !== value) ? 0 : value;
+      });
+
+      var actual = lodashStable.map(values, func);
+
+      assert.deepEqual(actual, expected);
+    });
+
     QUnit.test('`_.' + methodName + '` should convert number primitives and objects to numbers', function(assert) {
       assert.expect(1);