From 0e60831f46b863b3c5d7f5c0446f92f0bef232c3 Mon Sep 17 00:00:00 2001
From: John-David Dalton <john.david.dalton@gmail.com>
Date: Mon, 14 Jul 2014 08:59:28 -0700
Subject: [PATCH] Remove `sliceBuffer`, add typed array tests, and ensure typed
 array clones have the correct `byteOffset` and `length`.

---
 lodash.js    | 62 ++++++++++++++++++----------------------------------
 test/test.js | 47 +++++++++++++++++++++------------------
 2 files changed, 47 insertions(+), 62 deletions(-)

diff --git a/lodash.js b/lodash.js
index d484660ed..8004334a5 100644
--- a/lodash.js
+++ b/lodash.js
@@ -1427,8 +1427,7 @@
               if (Ctor instanceof Ctor) {
                 Ctor = ctorByClass[className];
               }
-
-              return new Ctor(sliceBuffer(value.buffer, value.byteOffset, value.length * Ctor.BYTES_PER_ELEMENT));
+              return new Ctor(cloneBuffer(value.buffer), value.byteOffset, value.length);
 
             case numberClass:
             case stringClass:
@@ -2904,7 +2903,26 @@
      * @returns {ArrayBuffer} Returns the cloned array buffer.
      */
     function cloneBuffer(buffer) {
-      return sliceBuffer(buffer, 0);
+      return bufferSlice.call(buffer, 0);
+    }
+    if (!bufferSlice) {
+      // PhantomJS has `ArrayBuffer` and `Uint8Array` but not `Float64Array`
+      cloneBuffer = !(ArrayBuffer && Uint8Array) ? identity : function(buffer) {
+        var byteLength = buffer.byteLength,
+            floatLength = Float64Array ? floor(byteLength / FLOAT64_BYTES_PER_ELEMENT) : 0,
+            offset = floatLength * FLOAT64_BYTES_PER_ELEMENT,
+            result = new ArrayBuffer(byteLength);
+
+        if (floatLength) {
+          var view = new Float64Array(result, 0, floatLength);
+          view.set(new Float64Array(buffer, 0, floatLength));
+        }
+        if (byteLength != offset) {
+          view = new Uint8Array(result, offset);
+          view.set(new Uint8Array(buffer, offset));
+        }
+        return result;
+      };
     }
 
     /**
@@ -2993,44 +3011,6 @@
       return result;
     }
 
-    /**
-     * Slices the given array buffer from the `start` index up to, but not including, the `end` index.
-     *
-     * @private
-     * @param {ArrayBuffer} buffer The array buffer to slice.
-     * @param {number} [start=0] The start index.
-     * @param {number} [end=buffer.byteLength] The end index.
-     * @returns {ArrayBuffer} Returns the slice of `buffer`.
-     */
-    function sliceBuffer(buffer, start, end) {
-      typeof start == 'number' || (start = 0);
-      typeof end == 'number' || (end = buffer.byteLength);
-      return bufferSlice.call(buffer, start, end);
-    }
-    if (!bufferSlice) {
-      // PhantomJS has `ArrayBuffer` and `Uint8Array` but not `Float64Array`
-      sliceBuffer = !(ArrayBuffer && Uint8Array) ? identity : function(buffer, start, end) {
-        typeof start == 'number' || (start = 0);
-        typeof end == 'number' || (end = buffer.byteLength);
-
-        var byteLength = end - start,
-            floatLength = Float64Array ? floor(byteLength / FLOAT64_BYTES_PER_ELEMENT) : 0,
-            offset = floatLength * FLOAT64_BYTES_PER_ELEMENT,
-            result = new ArrayBuffer(byteLength);
-
-        if (floatLength) {
-          var view = new Float64Array(result, 0, floatLength);
-          view.set(new Float64Array(buffer, start, floatLength));
-        }
-        if (byteLength != offset) {
-          offset += start;
-          view = new Uint8Array(result, offset);
-          view.set(new Uint8Array(buffer, offset));
-        }
-        return result;
-      };
-    }
-
     /**
      * An implementation of `_.uniq` optimized for sorted arrays without support
      * for callback shorthands and `this` binding.
diff --git a/test/test.js b/test/test.js
index 88ba459f2..9dde72d15 100644
--- a/test/test.js
+++ b/test/test.js
@@ -1460,23 +1460,6 @@
         });
       });
 
-      _.each(typedArrays, function(type) {
-	test('`_.' + methodName + '` should clone ' + type + ' arrays', 3, function() {
-          var Ctor = root[type];
-          if (Ctor) {
-            var array = new Ctor(new ArrayBuffer(8)),
-                actual = func(array);
-
-            deepEqual(actual, array);
-            notStrictEqual(actual, array);
-	    notStrictEqual(actual.buffer, array.buffer);
-          }
-          else {
-	    skipTest(3);
-          }
-        });
-      });
-
       test('`_.' + methodName + '` should clone array buffers', 2, function() {
         var buffer = ArrayBuffer && new ArrayBuffer(8);
         if (buffer) {
@@ -1489,6 +1472,28 @@
         }
       });
 
+      _.each(typedArrays, function(type) {
+        test('`_.' + methodName + '` should clone ' + type + ' arrays', 10, function() {
+          var Ctor = root[type];
+          if (Ctor) {
+            var array = new Ctor(new ArrayBuffer(24));
+
+            _.times(2, function(index) {
+              var actual = index ? func(array, 8, 1) : func(array);
+
+              deepEqual(actual, array);
+              notStrictEqual(actual, array);
+              notStrictEqual(actual.buffer, array.buffer);
+              strictEqual(actual.byteOffset, array.byteOffset);
+              strictEqual(actual.length, array.length);
+            });
+          }
+          else {
+            skipTest(10);
+          }
+        });
+      });
+
       test('`_.' + methodName + '` should clone problem JScript properties (test in IE < 9)', 2, function() {
         var actual = func(shadowedObject);
         deepEqual(actual, shadowedObject);
@@ -7454,8 +7459,8 @@
         }, 32);
       }
       else {
-      	skipTest();
-      	QUnit.start();
+        skipTest();
+        QUnit.start();
       }
     });
   }());
@@ -9788,8 +9793,8 @@
 
     test('should work with templates containing newlines and comments', 1, function() {
       var compiled = _.template('<%\n\
-	// comment\n\
-	if (value) { value += 3; }\n\
+        // comment\n\
+        if (value) { value += 3; }\n\
         %><p><%= value %></p>'
       );