text: describe("Works fine", function() {
  
      var prevDay = require('../index.js');
  
      //April 21, 2016, Thursday
      var today = new Date(2016, 3, 21);
      it("Monday", function() {
          var prevMonday = prevDay(today, 1);
          expect(prevMonday.date).toBeDefined();
          expect(prevMonday.date).toEqual(new Date(2016,3,18));
          expect(prevMonday.daySince).toBeDefined();
          expect(prevMonday.daySince).toEqual(3);
      });
      it("Tueday", function(){
          var prevTueday = prevDay(today, 2);
          expect(prevTueday.date).toBeDefined();
          expect(prevTueday.date).toEqual(new Date(2016,3,19));
          expect(prevTueday.daySince).toBeDefined();
          expect(prevTueday.daySince).toEqual(2);
      });
      it("Wednesday", function(){
          var prevWednesday = prevDay(today, 3);
          expect(prevWednesday.date).toBeDefined();
          expect(prevWednesday.date).toEqual(new Date(2016,3,20));
          expect(prevWednesday.daySince).toBeDefined();
          expect(prevWednesday.daySince).toEqual(1);
      });
      it("Thursday", function(){
          var prevThursday = prevDay(today, 4);
          expect(prevThursday.date).toBeDefined();
          expect(prevThursday.date).toEqual(new Date(2016,3,14));
          expect(prevThursday.daySince).toBeDefined();
          expect(prevThursday.daySince).toEqual(7);
      });
      it("Friday", function(){
          var prevFriday = prevDay(today, 5);
          expect(prevFriday.date).toBeDefined();
          expect(prevFriday.date).toEqual(new Date(2016,3,15));
          expect(prevFriday.daySince).toBeDefined();
          expect(prevFriday.daySince).toEqual(6);
      });
      it("Saturday", function(){
          var prevSaturday = prevDay(today, 6);
          expect(prevSaturday.date).toBeDefined();
          expect(prevSaturday.date).toEqual(new Date(2016,3,16));
          expect(prevSaturday.daySince).toBeDefined();
          expect(prevSaturday.daySince).toEqual(5);
      });
      it("Sunday", function(){
          var prevSunday = prevDay(today, 7);
          expect(prevSunday.date).toBeDefined();
          expect(prevSunday.date).toEqual(new Date(2016,3,17));
          expect(prevSunday.daySince).toBeDefined();
          expect(prevSunday.daySince).toEqual(4);
          expect(prevSunday).toEqual(prevDay(today, 0));
      });
  
      it("Constant", function(){
          expect(prevDay.Monday).toEqual(1);
          expect(prevDay.Tueday).toEqual(2);
          expect(prevDay.Wednesday).toEqual(3);
          expect(prevDay.Thursday).toEqual(4);
          expect(prevDay.Friday).toEqual(5);
          expect(prevDay.Saturday).toEqual(6);
          expect(prevDay.Sunday).toEqual(7);
      });
  
      it("undefined", function(){
          expect(prevDay(today, -1)).toBeUndefined();
          expect(prevDay(today, 8)).toBeUndefined();
      });
  });
  