Trigger works but test doesn't cover 75% of the code - triggers

Question

I have a trigger which works in the sandbox. The workflow checks the field in the campaign level and compares it with the custom setting. If it matches, then it returns the target to the DS Multiplier field. The trigger looks as follows
trigger PopulateTarget on Campaign (before insert, before update)
{
for(Campaign campaign : Trigger.new)
{
if (String.isNotBlank(campaign.Apex_Calculator__c) == true)
{
DSTargets__c targetInstance = DSTargets__c.getInstance(campaign.Apex_Calculator__c);
{
String target = targetInstance .Target__c;
campaign.DS_Target_Multiplier__c = Target;
}
}
}
}
However, I had problems to write a proper test to this and asked for the help on the internet. I received the test
#isTest
private class testPopulateTarget{
static testMethod void testMethod1(){
// Load the Custom Settings
DSTargets__c testSetting = new DSTargets__c(Name='Africa - 10 Weeks; CW 10',Target__c='0.1538', SetupOwnerId = apexCalculatorUserId);
insert testSetting;
// Create Campaign. Since it would execute trigger, put it in start and stoptests
Test.startTest();
Campaign testCamp = new Campaign();
// populate all reqd. fields.
testCamp.Name = 'test DS campaign';
testCamp.RecordTypeId = '012200000001b3v';
testCamp.Started_Campaign_weeks_before_Event__c = '12 Weeks';
testCamp.ParentId= '701g0000000EZRk';
insert testCamp;
Test.stopTest();
testCamp = [Select ID,Apex_Calculator__c,DS_Target_Multiplier__c from Campaign where Id = :testCamp.Id];
system.assertEquals(testCamp.DS_Target_Multiplier__c,testSetting.Target__c);// assert that target is populated right
}
}
Such test returns the error "Compile Error: Variable does not exist: apexCalculatorUserId at line 6 column 122". If I remove that ApexCalculator part System.assertEquals then the test passes. However it covers 4/6 part of the code (which is 66%)
Could anyone help me how should I amend the code to make the coverage of 75%?

Answer 1

Yes, apexCalculatorUserId has not been defined. The code you were given appears to be incomplete. You'll need to look at the constructor DSTargets__c and see what kind of ID it is expecting there.
At a guess, you could try UserInfo.getUserId() to get the ID of the current user, but that may not be the ID that's expected in the constructor. It would be worth trying it to see if the test coverage improves.

Answer 2

1) Replace apexCalculatorUserId with UserInfo.getUserId()
2) I'm not sure what kind of field is Apex_Calculator__c on campaign. If its not a formula you want to insert a new line before "insert testCamp". Something like:
testCamp.Apex_Calculator__c = UserInfo.getUserId();