How do you properly test for loop queries within test classes? - unit-testing

Question

I have a Schedulable class which will get called once per night. I have run the code anonymously and everything works as it should. The problem I am having is that I cannot get proper test coverage on it! I have written a test class that I believe should work, but for some reason any lines within my for-loops are not being covered.
I assume that it is because no data is being returned from these queries, however there are thousands of records that should be returned. I have run the queries on the production environment without any issues.
Is there a separate process for running queries in a schedulable class?
Here's part of my class:
global class UpdateUnitPrice implements Schedulable{
global void execute(SchedulableContext sc){
// OwnerId -> List of Strings with Row Contents
Map<Id,Map<Id,Map<String,String>>> updateContainer = new Map<Id,Map<Id,Map<String,String>>>{}; // Covered
List<Id> ownerContainer = new List<Id>{}; // Covered
String EmailMessage; // Covered
String EmailLine; // Covered
String EmailAddedLines; // Covered
String CurrentEmailLine; // Covered
String NewEmailLine; // Covered
List<Id> opportunityList = new List<Id>{}; // Covered
for(Opportunity thisOpp :[SELECT Id,Name FROM Opportunity WHERE Order_Proposed__c = null])
{
// Thousands of records should be returned
opportunityList.add(thisOpp.Id); // NOT COVERED!!
}
List<OpportunityLineItem> OppLineItemList = new List<OpportunityLineItem>{}; // Covered
for(OpportunityLineItem thisOppProd : [SELECT Id,OpportunityId,Opportunity.OwnerId,Opportunity.Name,Product_Name__c,UnitPrice,ListPrice
FROM OpportunityLineItem
WHERE OpportunityId IN :opportunityList
AND UnitPrice_lt_ListPrice__c = 'True'
ORDER BY OpportunityId ASC])
{
. . . // NO LINES COVERED WITHIN THIS LOOP
}
. . .
}
}
Here's my test class:
#isTest
private class UpdateUnitPriceTest {
static testMethod void myUnitTest() {
Test.startTest();
// Schedule the test job
String jobId = System.schedule('UpdateUnitPrice','0 0 0 3 9 ? 2022',new UpdateUnitPrice());
// Get the information from the CronTrigger API object
CronTrigger ct = [SELECT Id, CronExpression, TimesTriggered, NextFireTime FROM CronTrigger WHERE id = :jobId];
// Verify the expressions are the same
System.assertEquals(ct.CronExpression,'0 0 0 3 9 ? 2022');
// Verify the job has not run
System.assertEquals(0, ct.TimesTriggered);
// Verify the next time the job will run
System.assertEquals('2022-09-03 00:00:00', String.valueOf(ct.NextFireTime));
Test.stopTest();
}
}
Am I supposed to specifically reference something within these for-loops for them to fire? This Class should be able to just run everything on it's own without inserting records for testing. What am I missing?
Thanks in advance for any help given!

Answer 1

There was a lovely feature added to API 24.0 which requires test classes to include a small (new) line of code in order to view queried data. I have no idea why this was implemented, but it sure did trip me up.
For our test classes to run properly, they now must have the following at the top:
#isTest (SeeAllData = true)
Previously, all that was needed was:
#isTest
You can read more on test classes and this new "feature" here: Apex Test Class Annotations