When testing the callouts that Chargent makes, you can’t use the HttpCalloutMock class in Salesforce because it has to be done from within the Chargent managed package/namespace. To create sample responses and make sure that your code behaves appropriately, here is a workaround:
Wrap the actually call to Chargent Webservices in a
if(!test.isRunnungTest()){
code that makes call out here
}else{
//create a transaction record manually or set whatever values need for your test to continue
}
Uncommitted Work Errors
Purpose
When building a custom visualforce page that will be using Chargent Webservice Methods to process a charge there is a potential that you may receive an error from Salesforce when executing the Chargent Webservice Method as follows:
You have uncommitted work pending. Please commit or rollback before calling out
Background
One of the framework requirements when developing on the Salesforce platform is that you cannot perform any DML prior to making a callout to any external service in the same transaction. Chargent Webservices, when executed, makes a callout to the appropriate gateway to process the charge, thus you cannot perform any DML prior to executing a method from Chargent Webservices.
Solution
Within the lifecycle of a Visualforce page, each execution of a controller method from the Visualforce page itself is a separate transaction. The key is that individual execution of the method must come from the page and not from the controller.
The following is an example of a minimalistic page and controller. It is intended only to show the typical pattern that causes the issue.
Error Example:
Page

Controller

When the command button is clicked it executes the update_and_charge() method. That method then updates the Chargent Order record and then attempts to execute the charge() method. When the charge() method executes the ChargentWebservices Orders_Click method and attempts to make the callout to the gateway you will receive the error message.
The solution is to break up the calls using the oncomplete tag on the command button in conjunction with an apex:actionFunction to call the charge() method. This solution follows:
Working Example
Page

Controller

Notice that on the page we added an apex:actionFunction to call the charge() method in the controller on completion of the update_and_charge() method. Also, we removed the call to the charge() method from the controller that was on line 11 in the error example.
In doing this, on click of the command button the update_and_charge() method is executed which updates the Chargent Order and then the transaction finishes and returns control to the page. The page then calls the actionFunction via the oncomplete tag and then executes the charge() method in the controller in a separate transaction without producing any errors.