Request body :

{
    "StartDate": "2019-08-01",
    "EndDate": "2019-12-03"
}

Method : Post

Need to pass these parameters in my test class not sure how i cna do this

Test clasS:

static testMethod void testPost() {
        RestRequest req = new RestRequest(); 
        RestResponse res = new RestResponse();             
        req.requestURI = '/services/apexrest/WorkdayIntegration/';
        req.httpMethod = 'POST';
        RestContext.request = req;
        //req.requestBody=('2019/05/05','2019/06/05');
        RestContext.response= res;
        APTS_InvoiceDetailsWS.APTS_WorkdayIntegrationWrapper  results = APTS_InvoiceDetailsWS.getInvoiceDetails();
      
      
  }


Method :