Add stacked tests

spec/stacked-spec.js

+
+describe('c3 stacked', function () {
+    'use strict';
+
+    var chart, d3;
+
+    var args = {
+        data: {
+            columns: [
+                ['data1', 30, 200, 100, 400, 150, 250],
+                ['data2', 50, 20, 10, 40, 15, 25],
+                ['data3', 150, 120, 110, 140, 115, 125]
+            ],
+            type: 'column'
+        },
+        normalized: true
+    };
+
+    beforeEach(function (done) {
+        chart = window.initChart(chart, args, done);
+    });
+
+    it("should sum to 1", function(done){
+        var data = chart.data();
+        for(var i = 0; i < 6; i++){
+            var s = 0;
+
+            data.forEach(function(column){
+                s += column.values[i].value;
+            });
+
+            expect(s).toBeCloseTo(1);
+        }
+
+        done();
+    });
+
+    it("should sum to 1 even with big data", function(done){
+        chart.load({
+            columns:
+                [
+                    ['data1', 1, 1, 1, 1, 100, 20],
+                    ['data2', 100, 1, 1, 1, 1, 0.1],
+                    ['data3', 1, 1000, 1, 1, 1, 0.1]
+                ]
+        });
+
+        var data = chart.data();
+        
+        for(var i = 0; i < 6; i++){
+            var s = 0;
+
+            data.forEach(function(column){
+                s += column.values[i].value;
+            });
+
+            expect(s).toBeCloseTo(1);
+        }
+
+        done();
+
+    });
+
+});
+
+