Added AccountRepository and bugfix for fieldsets that include SystemModstamp, which has weird casing in Salesforce

Author: James Simone

src/classes/AccountRepository.cls-meta.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ApexClass xmlns="http://soap.sforce.com/2006/04/metadata">
+    <apiVersion>38.0</apiVersion>
+    <status>Active</status>
+</ApexClass>

src/classes/AccountRepository_Tests.cls

@@ -0,0 +1,28 @@
+@isTest
+public class AccountRepository_Tests {
+    @testSetup
+    static void setupData() {
+        List<Account> accounts = new List<Account>();
+        for(Integer i =0; i <3; i++) {
+            Account account = new Account();
+            account.FirstName = 'George' + i;
+            account.LastName = 'Washington';
+            account.AladdinCustomerId__c = (Decimal)RandomizerUtils.generateInteger(10) + i;
+
+            accounts.add(account);
+        }
+
+        insert accounts;
+    }
+
+    @isTest
+    static void it_should_return_an_account_by_id() {
+        Account account = [SELECT Id FROM Account LIMIT 1];
+
+        Test.startTest();
+        Account returnedAccount = new AccountRepository().getById(account.Id);
+        Test.stopTest();
+
+        System.assertEquals(account.Id,returnedAccount.Id);
+    }
+}

src/classes/SObjectRepository.cls

@@ -9,7 +9,7 @@ public abstract class SObjectRepository implements ISObjectRepository {
     private Map<String, Schema.SObjectField> sobjectTypeFieldMap;
     private Set<String> queryFields;
     private String query;
-    private Boolean addCommonQueryFields;
+    private Boolean shouldAddCommonFields;
     private Schema.FieldSet fieldSet;
     private List<String> whereClauseList;
     private List<String> orderByList;
@@ -20,16 +20,16 @@ public abstract class SObjectRepository implements ISObjectRepository {
         this(fieldSet, true);
     }
 
-    protected SObjectRepository(Schema.FieldSet fieldSet, Boolean addCommonQueryFields) {
-        this.fieldSet             = fieldSet;
-        this.addCommonQueryFields = addCommonQueryFields;
+    protected SObjectRepository(Schema.FieldSet fieldSet, Boolean shouldAddCommonFields) {
+        this.fieldSet              = fieldSet;
+        this.shouldAddCommonFields = shouldAddCommonFields;
 
-        this.sobjectType         = fieldSet.getSObjectType();
-        this.sobjectTypeFieldMap = this.sobjectType.getDescribe().fields.getMap();
-        this.queryFields         = new Set<String>();
-        this.whereClauseList     = new List<String>();
-        this.orderByList         = new List<String>();
-        this.forUpdate           = false;
+        this.sobjectType           = fieldSet.getSObjectType();
+        this.sobjectTypeFieldMap   = this.sobjectType.getDescribe().fields.getMap();
+        this.queryFields           = new Set<String>();
+        this.whereClauseList       = new List<String>();
+        this.orderByList           = new List<String>();
+        this.forUpdate             = false;
 
         this.addCommonQueryFields();
         this.addFieldSetMembers();
@@ -94,24 +94,31 @@ public abstract class SObjectRepository implements ISObjectRepository {
     protected void doDelete(List<SObject> records) {Database.delete(records);}
 
     private void addCommonQueryFields() {
-        if(!this.addCommonQueryFields) return;
+        if(!this.shouldAddCommonFields) return;
 
         // Auto-add the common fields that are available for the SObject Type
-        List<String> commonFieldNameList = new List<String>{
+        Set<String> commonFieldNameList = new Set<String>{
             'Id', 'CaseNumber', 'CreatedById', 'CreatedDate',  'IsClosed', 'LastModifiedById', 'LastModifiedDate',
             'Name', 'OwnerId', 'Subject', 'RecordTypeId', 'SystemModStamp'
         };
+
         for(String commonFieldName : commonFieldNameList) {
+            //Verify that the field is available on the object being used
             if(!this.sobjectTypeFieldMap.containsKey(commonFieldName)) continue;
 
-            this.queryFields.add(commonFieldName);
+            //Salesforce has some inconsistencies in casing for standard field names. We'll go lowercase
+            //here and in addFieldSetMembers() to ensure the set is unique
+            this.queryFields.add(commonFieldName.toLowerCase());
         }
     }
 
     private void addFieldSetMembers() {
         if(this.fieldSet == null) return;
 
-        for(Schema.FieldSetMember field : this.fieldSet.getFields()) this.queryFields.add(field.getFieldPath());
+        for(Schema.FieldSetMember field : this.fieldSet.getFields()) {
+            //Lowercase here as well to ensure strings added to the set are unique
+            this.queryFields.add(field.getFieldPath().toLowerCase());
+        }
     }
 
     private SObjectRepository addCondition(Schema.SObjectField field, String operator, String value) {