fix bug in slice method

Denys-Bushulyak · Feb 5, 2015 · 59b7a8d · 59b7a8d
1 parent 36de0bc
commit 59b7a8d
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diff --git a/chain.js b/chain.js
@@ -104,6 +104,7 @@ function Chain(items) {
 
     function _slice(start, length){
         var out = [];
+        length = length || Number.POSITIVE_INFINITY;
         for(var i in _items){
             if(i >= start && i <= length){
                 out.push(_items[i]);

diff --git a/test/test.js b/test/test.js
@@ -23,6 +23,29 @@ describe("Testing Chain", function () {
         })
     });
 
+    describe("Testing slice function",function(){
+        var chain = new Chain(arr);
+
+        it("expecting chain will be 4 items length", function(){
+            expect(chain.count()).toBe(5);
+        });
+
+        it("expecting chain will be 4 items length", function(){
+
+            chain = chain.slice(1);
+
+            expect(chain.count()).toBe(4);
+            expect(chain.first()).toBe(1);
+            expect(chain.last()).toBe(null);
+            expect(chain.last()).toBeNull();
+
+            chain = chain.slice(1,2);
+
+            expect(chain.first()).toBe(3);
+            expect(chain.last()).toBe(-2);
+        });
+    });
+
     describe("Begin sub chain", function(){
         var chain = new Chain(arr);