How to Specify System.now() in Json while creating a record

Question

I'm creating a record in a test class that needs a specific LastModifiedDate, that date would be, today's date minus 365 days. When I create the record, this is what the code looks like:

String OppJSON = '{"attributes":{"type":"Opportunity","url":"/services/data/v25.0/sobjects/Opportunity/500E0000002nH2fIAE"},"Id":"500E0000002nH2fIAE","LastModifiedDate":"2015-01-06T17:54:26.000+0000"}';
Opportunity opp = (Opportunity) JSON.deserialize(OppJSON, Opportunity.class );

But I would like to instead of manually specify the datetime of LastModifiedDate to take today's date/time and substract 365 days. What would the syntax look like for this? I know I can do this:

Datetime oneyearago = System.today().addDays(-365);
String value = String.valueOf(oneyearago);

but I don't know how to use that value string in my json. Thanks in advanced.

Answer 1

There's probably a neater way to do it but you could just serialize the date into a string like so:

Datetime oneyearago = System.today().addDays(-365);
String jsonDatetime = JSON.serialize(oneyearago);

Which outputs the specified date in the correct format:

2015-01-06T00:00:00.000Z

In response to your comment:

String OppJSON = '{"attributes":{"type":"Opportunity","url":"/services/data/v25.0/sobjects/Opport‌​unity/500E0000002nH2fIAE"},"Id":"500E0000002nH2fIAE","LastModifiedDate":' + jsonDatetime + '}';

Opportunity opp = (Opportunity) JSON.deserialize(OppJSON, Opportunity.class );

Updated with a string that works correctly, but really you should look into crop1645's approach as that is more aligned with unit testing best practices.

Answer 2

One way around this issue is to create testdata with whatever dates you want, including the current date and change the logic of your application to rely on a Utility class property:

Date todayDt {
    get {return todayDt == null ? Date.today() : todayDt;}
    set;
}

and everywhere in your PROD code when you need to reference "today", you don't use Date.today() but instead Utility.todayDt

Your testmethod can thus create testdata with audit field dates to whatever you want (from today onwards) and then before you execute test.StartTest(), do

Utility.todayDt = Date.today().addDays(180); // example - for creating testdata with audit dates 0...180 days in past

Your PROD code will think that "today" is 180 days from the real today but as long as all references to Date.today() are changed to the Utility.todayDt; everything works. Sort of a "back to the future"