Add tests for IOUtils

test/specs/io/utils.js

@@ -0,0 +1,24 @@
+"use strict";
+
+var Utils = source('io/utils.js');
+
+describe("IOUtils", function() {
+  describe("#periodAndDuty", function() {
+    var fn = Utils.periodAndDuty;
+
+    it("calculates values for PWM", function() {
+      var value = fn(0.5, 2000, null, null);
+      expect(value).to.be.eql({ period: 500000, duty: 250000 })
+    });
+
+    it("calculates values for servos", function() {
+      var value = fn(0.5, 50, { min: 500, max: 2400 }, 'high');
+      expect(value).to.be.eql({ duty: 1450000, period: 20000000 })
+    });
+
+    it("calculates values for different polarities", function() {
+      var value = fn(0.5, 50, { min: 500, max: 2400 }, 'low');
+      expect(value).to.be.eql({ duty: 18550000, period: 20000000 })
+    });
+  });
+});