Custom Jasmine Matchers

AnotherBloatedDateTest.js

it("convertToSplitDate should turen a Date into a split date", function() {
    var date = new Date(2012, 10, 17),
        splitDate = dateUtil.convertDateToSplitDate(date);

    expect(splitDate).toBeDefined();
    expect(splitDate.year).toBe(date.year);
    expect(splitDate.month - 1).toBe(date.month);
    expect(splitDate.day).toBe(date.day);
});

BloatedDateTest.js

it("convertToDate should turn a splitDate into a Date object", function() {
    var splitDate = {year: 2012, month: 11, day: 17},
        date = dateUtil.splitDateToDate(splitDate);
    
    expect(date instanceof Date).toBe(true);
    expect(date.getFullYear()).toBe(splitDate.year);
    expect(date.getMonth()).toBe(splitDate.month - 1);
    expect(date.getDate()).toBe(splitDate.day);
});

CleanTests.js

it("convertToDate should turn a splitDate into a Date object", function() {
    var splitDate = {year: 2012, month: 11, day: 17},
        date = dateUtil.splitDateToDate(splitDate);
    
    expect(date).toEqualDate(splitDate);
});

it("convertToSplitDate should turen a Date into a split date", function() {
    var date = new Date(2012, 10, 17),
        splitDate = dateUtil.convertDateToSplitDate(date);

    expect(splitDate).toEqualDate(date);
});

CustomMatchers.js

//Jasmine will call this before EVERY spec.
beforeEach(function () {
    function isValidSplitDate(splitDate) {
        return splitDate && !isNaN(splitDate.year) && !isNaN(splitDate.month) && !isNaN(splitDate.day);
    }

    function convertSplitDateToDate(splitDate) {
        if (isValidSplitDate(splitDate)) {
            splitDate = new Date(splitDate.year, splitDate.month - 1, splitDate.day);
        }
        return splitDate;
    }
   
    //addMatchers() is a method that Jasmine will see and understand to 
    //make the custom matchers within easy to understand.
    this.addMatchers({
        toEqualDate: function (expectedDate) {
            var areDates;

            expectedDate = convertSplitDateToDate(expectedDate);
            this.actual = convertSplitDateToDate(this.actual);

            areDates = this.actual instanceof Date && expectedDate instanceof Date;

            //Jasmine will look for this function and utilize it for custom error messages
            this.message = function () {
                if (areDates) {
                    return "Expected date of " + this.actual + " to be " + expectedDate;
                }
                return "Expected " + this.actual + " and " + expectedDate + " to be valid Date/SplitDate objects. They were not.";
            };

            if (areDates) {
                //Ultimately Jasmine expects a matcher to return true or false
                return (this.actual.getTime() === expectedDate.getTime());
            }

            return false;
        }
    });
});