Pass a List with a custom object type as a parameter

Question

I am trying to increase my code coverage, I have only provided parts of my code that I am trying to cover. I have to create a List to be able to pass over my values into the method. My Errors I have listed below.

• Expecting'<' but was '('
• Invalid type: AccountParameter

• method does not exist or incorrect signature void handleNewAccounts(List) from the type ProcessHandlerShowAccounts

  @isTest
  public class ProcessHandlerShowAccountsTest {
   @isTest static void testCallout() {
  
      ProcessHandlerShowAccounts.AccountParameter testAccount = new ProcessHandlerShowAccounts.AccountParameter();
      testAccount.accountId = '0010Z00000schfZZZZ';
      testAccount.name = 'create';
  //I get my 1st two errors here
      LIST<AccountParameter> testActLst = new LIST();
  //I get my last error here
      ProcessHandlerShowAccounts.handleNewAccounts(testActLst);
  
  }
  
  }
  

Method I am trying to call lives within this Class

public class ProcessHandlerShowAccounts 
{
    public class AccountParameter
    {
        @InvocableVariable(required=true)
        public Id accountId;
        @InvocableVariable(required=true)
        public String name;
    }

 public static void handleNewAccounts(AccountParameter [] accountParameters) 
    {

webServiceCallOut(accountParameters[0].accountId,accountParameters[0].name);      
    isAlreadyRun=true;    
    }  

}

Answer 1

You have to provide the fully qualified parameterized type name to the new operator:

List<AccountParameter> testActLst = new List<AccountParameter>();

You can't instantiate the type List as such.

That's what these errors are telling you. It found a ( where it was expecting <, from the type name. Then it got confused about the type of your variable, and found there's no method handleNewAccounts that takes a List, because you cannot have an untyped List.