Apex Testing- Get Started with Apex Unit Tests

Challenge 13:
Create a unit test for a simple Apex class.
Install a simple Apex class, write unit tests that achieve 100% code coverage for the class, and run your Apex tests.
The Apex class to test is called 'VerifyDate', and the code is available here. Copy and paste this class into your Developer Edition via the Developer Console.
'VerifyDate' is a class which tests if a date is within a proper range, and if not will return a date that occurs at the end of the month within the range.
The unit tests must be in a separate test class called 'TestVerifyDate'.
The unit tests must cover scenarios for all lines of code included in the Apex class, resulting in 100% code coverage.
Run your test class at least once (via 'Run All' tests the Developer Console) before attempting to verify this challenge.


Solution:

1.VerifyDate.apxc

public class VerifyDate {
	
	//method to handle potential checks against two dates
	public static Date CheckDates(Date date1, Date date2) {
		//if date2 is within the next 30 days of date1, use date2.  Otherwise use the end of the month
		if(DateWithin30Days(date1,date2)) {
			return date2;
		} else {
			return SetEndOfMonthDate(date1);
		}
	}
	
	//method to check if date2 is within the next 30 days of date1
	private static Boolean DateWithin30Days(Date date1, Date date2) {
		//check for date2 being in the past
        	if( date2 < date1) { return false; }
        
        	//check that date2 is within (>=) 30 days of date1
        	Date date30Days = date1.addDays(30); //create a date 30 days away from date1
		if( date2 >= date30Days ) { return false; }
		else { return true; }
	}

	//method to return the end of the month of a given date
	private static Date SetEndOfMonthDate(Date date1) {
		Integer totalDays = Date.daysInMonth(date1.year(), date1.month());
		Date lastDay = Date.newInstance(date1.year(), date1.month(), totalDays);
		return lastDay;
	}

}


2.TestVerifyDate.apxc

@isTest
private class TestVerifyDate {
    static testMethod void TestVerifyDate() {
      VerifyDate.CheckDates(System.today(),System.today().addDays(10));
       VerifyDate.CheckDates(System.today(),System.today().addDays(78));
    }
}