tests against native reduce

.gitignore

@@ -1,2 +1,3 @@
 components
 build
+node_modules

Makefile

@@ -6,6 +6,11 @@ components: component.json
 	@component install --dev
 
 clean:
-	rm -fr build components template.js
+	rm -fr build components
 
-.PHONY: clean
+test:
+	@./node_modules/.bin/mocha \
+		--require should \
+		--reporter spec
+
+.PHONY: clean test

component.json

@@ -1,8 +1,8 @@
 {
   "name": "reduce",
   "repo": "redventures/reduce",
-  "description": "array reduce",
-  "version": "0.0.0",
+  "description": "Array reduce component",
+  "version": "0.0.1",
   "keywords": ["array", "reduce"],
   "dependencies": {},
   "development": {},

index.js

@@ -9,15 +9,15 @@
  * TODO: combatible error handling?
  */
 
-module.exports = function(arr, fn, initial){
+module.exports = function(arr, fn, initial){  
   var idx = 0;
   var len = arr.length;
   var curr = arguments.length == 3
     ? initial
-    : arr[0];
+    : arr[idx++];
 
-  while (++idx < len) {
-    curr = fn.call(null, curr, arr[idx], idx, arr);
+  while (idx < len) {
+    curr = fn.call(null, curr, arr[idx], ++idx, arr);
   }
 
   return curr;

package.json

@@ -0,0 +1,14 @@
+{
+  "name": "reduce",
+  "description": "Array reduce component",
+  "version": "0.0.1",
+  "devDependencies": {
+    "mocha": "*",
+    "should": "*"
+  },
+  "component": {
+    "scripts": {
+      "reduce": "index.js"
+    }
+  }
+}

test/reduce.js

@@ -0,0 +1,49 @@
+
+var reduce = require('..');
+
+describe('reduce', function(){
+
+  describe('when adding prev and current', function(){
+    it('should be sum all the values', function(){
+      var numbers = [2,2,2];
+      var fn = function(prev, curr){
+        return prev + curr;
+      };
+
+      var a = numbers.reduce(fn);
+      var b = reduce(numbers, fn);
+
+      a.should.equal(6);
+      b.should.equal(a);
+    });
+  });
+
+  describe('when passing in an initial value', function(){
+    it('should default to it', function(){
+      var items = [];
+      var fn = function(prev){
+        return prev;
+      };
+
+      var a = items.reduce(fn, 'foo');
+      var b = reduce(items, fn, 'foo');
+
+      a.should.equal('foo');
+      b.should.equal(a);
+    });
+
+    it('should start with it', function(){
+      var items = [10, 10];
+      var fn = function(prev, curr){
+        return prev + curr;
+      };
+
+      var a = items.reduce(fn, 10);
+      var b = reduce(items, fn, 10);
+
+      a.should.equal(30);
+      b.should.equal(a);
+    });
+  });
+
+});