From 3d79427cd66c8d86ed7889c27875cf5725e260a9 Mon Sep 17 00:00:00 2001
From: Piotr Gajek <piotr.gajek95@gmail.com>
Date: Wed, 18 Dec 2024 15:06:45 +0100
Subject: [PATCH] Cannot modify a collection while it is being iterated Fix
 (#133)

* Cannot modify a collection while it is being iterated Fix

Signed-off-by: Piotr PG Gajek <piotr.gajek95@gmail.com>

* Code refactoring

Signed-off-by: Piotr PG Gajek <piotr.gajek95@gmail.com>

* groupByWithDefaultFieldsAndAggregateFunction unit test

Signed-off-by: Piotr PG Gajek <piotr.gajek95@gmail.com>

---------

Signed-off-by: Piotr PG Gajek <piotr.gajek95@gmail.com>
---
 force-app/main/default/classes/SOQL.cls            | 13 +++----------
 force-app/main/default/classes/SOQL.cls-meta.xml   |  2 +-
 force-app/main/default/classes/SOQL_Test.cls       | 14 ++++++++++++++
 .../main/default/classes/SOQL_Test.cls-meta.xml    |  2 +-
 4 files changed, 19 insertions(+), 12 deletions(-)

diff --git a/force-app/main/default/classes/SOQL.cls b/force-app/main/default/classes/SOQL.cls
index 7ed6810..e9866c6 100644
--- a/force-app/main/default/classes/SOQL.cls
+++ b/force-app/main/default/classes/SOQL.cls
@@ -1119,7 +1119,9 @@ public virtual inherited sharing class SOQL implements Queryable {
             if (!groupedFields.isEmpty() || !aggregateFunctions.isEmpty()) {
                 List<String> selectFields = new List<String>();
 
-                removeNotGroupedFields();
+                // To avoid "Field must be grouped or aggregated" error
+                // retain only grouped or aggregated fields
+                fields.retainAll(groupedFields);
 
                 selectFields.addAll(fields);
                 selectFields.addAll(aggregateFunctions);
@@ -1129,15 +1131,6 @@ public virtual inherited sharing class SOQL implements Queryable {
 
             return 'SELECT ' + String.join(fields, ', ');
         }
-
-        public void removeNotGroupedFields() {
-             // To avoid "Field must be grouped or aggregated" error
-            for (String field : fields) {
-                if (!groupedFields.contains(field)) {
-                    fields.remove(field);
-                }
-            }
-        }
     }
 
     private class SoqlSubQuery implements SubQuery {
diff --git a/force-app/main/default/classes/SOQL.cls-meta.xml b/force-app/main/default/classes/SOQL.cls-meta.xml
index 651b172..998805a 100644
--- a/force-app/main/default/classes/SOQL.cls-meta.xml
+++ b/force-app/main/default/classes/SOQL.cls-meta.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <ApexClass xmlns="http://soap.sforce.com/2006/04/metadata">
-    <apiVersion>61.0</apiVersion>
+    <apiVersion>62.0</apiVersion>
     <status>Active</status>
 </ApexClass>
diff --git a/force-app/main/default/classes/SOQL_Test.cls b/force-app/main/default/classes/SOQL_Test.cls
index 3d9a31f..0a83674 100644
--- a/force-app/main/default/classes/SOQL_Test.cls
+++ b/force-app/main/default/classes/SOQL_Test.cls
@@ -1965,6 +1965,20 @@ private class SOQL_Test {
         Assert.areEqual('SELECT LeadSource FROM Lead GROUP BY LeadSource', soql);
     }
 
+    @IsTest
+    static void groupByWithDefaultFieldsAndAggregateFunction() {
+        // Test
+        String soql = SOQL.of(Lead.SObjectType)
+            .with(Lead.FirstName, Lead.LastName, Lead.Email)
+            .count(Lead.Name)
+            .with(Lead.LeadSource)
+            .groupBy(Lead.LeadSource)
+            .toString();
+
+        // Verify
+        Assert.areEqual('SELECT LeadSource, COUNT(Name) FROM Lead GROUP BY LeadSource', soql);
+    }
+
     @IsTest
     static void havingFilterWithSObjectField() {
         // Test
diff --git a/force-app/main/default/classes/SOQL_Test.cls-meta.xml b/force-app/main/default/classes/SOQL_Test.cls-meta.xml
index 651b172..998805a 100644
--- a/force-app/main/default/classes/SOQL_Test.cls-meta.xml
+++ b/force-app/main/default/classes/SOQL_Test.cls-meta.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <ApexClass xmlns="http://soap.sforce.com/2006/04/metadata">
-    <apiVersion>61.0</apiVersion>
+    <apiVersion>62.0</apiVersion>
     <status>Active</status>
 </ApexClass>