How to refer PageReference method from apex test class - unit-testing

Question

I am new to apex, I have created a button to call the apex class through the visual force page.
Here is my visual force page code.
<apex:page standardController="Opportunity"
extensions="myclass"
action="{!autoRun}">
</apex:page>
Here is my apex class.
public class myclass {
private final Opportunity o;
String tmp;
public myclass(ApexPages.StandardController stdController) {
this.o = (Opportunity)stdController.getRecord();
}
public PageReference autoRun() {
String theId = ApexPages.currentPage().getParameters().get('id');
for (Opportunity o:[select id, name, AccountId, from Opportunity where id =:theId]) {
//Create the Order
Order odr = new Order(
OpportunityId=o.id
,AccountId = o.AccountId
,Name = o.Name
,EffectiveDate=Date.today()
,Status='Draft'
);
insert odr;
tmp=odr.id;
}
PageReference pageRef = new PageReference('/' + tmp);
pageRef.setRedirect(true);
return pageRef;
}
}
I want to create test class. I don't know how to refer PageReference autoRun() method from test class. Guys need help if some one can tell me about test class of this apex class.

Answer 1

You will need to configure the StandardController for the inserted Opportunity. Then pass the StandardController to pass to the constructor before calling the method to test.
E.g.
public static testMethod void testAutoRun() {
Opportunity o = new Opportunity();
// TODO: Populate required Opportunity fields here
insert o;
PageReference pref = Page.YourVisualforcePage;
pref.getParameters().put('id', o.id);
Test.setCurrentPage(pref);
ApexPages.StandardController sc = new ApexPages.StandardController(o);
myclass mc = new myclass(sc);
PageReference result = mc.autoRun();
System.assertNotEquals(null, result);
}