How to Write a Test Class for Webservice Class?

Question

Situation

I wrote a web service class. From my understanding unit tests in salesforce are supposed to test the whole functionality (end to end). But I don't know how to test this external interface.

Therefore my question is:

• Am I supposed to call the web service class from outside?
• How to Write a Test Class for Webservice Class?

Code

   global class ObjectFieldUpdate2{  

    global class RequiredFields{
         webservice String FieldName; 
         webservice String FieldValue;
    }

    webservice static String FiledtoUpdate2(String ObjName,Integer ExtId, List<RequiredFields> fieldvalues){
        String str='';
        Schema.SObjectType t = Schema.getGlobalDescribe().get(ObjName);
        if(t!=null){
            String query = 'select Id' + ' from ' + ObjName +' where External_Id__c ='+ExtId+' Limit 1';
            SObject s = Database.query(query);
            if(s!=null){
               SObject sObjectUpdate = t.newSObject(s.Id);
                try{
                    for(RequiredFields flds : fieldvalues)      
                       sObjectUpdate.put(flds.FieldName, flds.FieldValue);

                    if(sObjectUpdate!=null)
                      Update sObjectUpdate;

                }catch(Exception e){
                    str=e.getMessage();
                } 
            } 
        }   
        if(str=='')
            return 'Success';
        else
            return str;         
    }


}

Answer 1

Welcome to the community SFDC developer!

Background

In Salesforce it is possible to use unit tests to make sure that the implemented code unit works as expected for a given scenario. All tests should be performed with data which was created for the test scenario. The usage of existing data is allowed but not recommended. However, in order to run tests in an encapsulated environment you are not allowed to use callouts to other services. (This could result in inconsistencies.. Therefore you have to mock these external services using HTTPCalloutMock).

Answer

However, in your case you implemented a global class which is exposed as a web service. You are not allowed to call web services during tests. Therefore it is not possible to call your own service from outside to test it. My suggestion therefore is that you implement a standard unit test (like all the other unit test, which implements a simple test).

The test class could look like this:

What follows is pseudo code.

@isTest    
class ObjectFieldUpdate2_Test
{
    private static void test()
    {
        ObjectFieldUpdate2_Test.RequiredFields a = new ObjectFieldUpdate2_Test.RequiredFields();
        a.FieldName = 'Name';
        ObjectFieldUpdate2.FiledtoUpdate2('Contact', 1, new List<ObjectFieldUpdate2_Test.RequiredFields>{a});
    }

}