Salesforce Apex Quality Guardrails Apply these checks to every Apex class, trigger, and test file you write or review. Step 1 — Governor Limit Safety Check Scan for these patterns before declaring any Apex file acceptable: SOQL and DML in Loops — Automatic Fail // ❌ NEVER — causes LimitException at scale for ( Account a : accounts ) { List < Contact

contacts

[ SELECT Id FROM Contact WHERE AccountId = :a . Id ] ; // SOQL in loop update a ; // DML in loop } // ✅ ALWAYS — collect, then query/update once Set < Id

accountIds

new Map < Id , Account

( accounts ) . keySet ( ) ; Map < Id , List < Contact

contactsByAccount

new Map < Id , List < Contact

( ) ; for ( Contact c : [ SELECT Id , AccountId FROM Contact WHERE AccountId IN :accountIds ] ) { if ( ! contactsByAccount . containsKey ( c . AccountId ) ) { contactsByAccount . put ( c . AccountId , new List < Contact

( ) ) ; } contactsByAccount . get ( c . AccountId ) . add ( c ) ; } update accounts ; // DML once, outside the loop Rule: if you see [SELECT or Database.query , insert , update , delete , upsert , merge inside a for loop body — stop and refactor before proceeding. Step 2 — Sharing Model Verification Every class must declare its sharing intent explicitly. Undeclared sharing inherits from the caller — unpredictable behaviour. Declaration When to use public with sharing class Foo Default for all service, handler, selector, and controller classes public without sharing class Foo Only when the class must run elevated (e.g. system-level logging, trigger bypass). Requires a code comment explaining why. public inherited sharing class Foo Framework entry points that should respect the caller's sharing context If a class does not have one of these three declarations, add it before writing anything else . Step 3 — CRUD / FLS Enforcement Apex code that reads or writes records on behalf of a user must verify object and field access. The platform does not enforce FLS or CRUD automatically in Apex. // Check before querying a field if ( ! Schema . sObjectType . Contact . fields . Email . isAccessible ( ) ) { throw new System . NoAccessException ( ) ; } // Or use WITH USER_MODE in SOQL (API 56.0+) List < Contact

contacts

[ SELECT Id , Email FROM Contact WHERE AccountId = :accId WITH USER_MODE ] ; // Or use Database.query with AccessLevel List < Contact

contacts

Database . query ( 'SELECT Id, Email FROM Contact' , AccessLevel . USER_MODE ) ; Rule: any Apex method callable from a UI component, REST endpoint, or @InvocableMethod must enforce CRUD/FLS. Internal service methods called only from trusted contexts may use with sharing instead. Step 4 — SOQL Injection Prevention // ❌ NEVER — concatenates user input into SOQL string String soql = 'SELECT Id FROM Account WHERE Name = \'' + userInput + '\'' ; // ✅ ALWAYS — bind variable String soql = [ SELECT Id FROM Account WHERE Name = :userInput ] ; // ✅ For dynamic SOQL with user-controlled field names — validate against a whitelist Set < String

allowedFields

new Set < String

{ 'Name' , 'Industry' , 'AnnualRevenue' } ; if ( ! allowedFields . contains ( userInput ) ) { throw new IllegalArgumentException ( 'Field not permitted: ' + userInput ) ; } Step 5 — Modern Apex Idioms Prefer current language features (API 62.0 / Winter '25+): Old pattern Modern replacement if (obj != null) { x = obj.Field__c; } x = obj?.Field__c; x = (y != null) ? y : defaultVal; x = y ?? defaultVal; System.assertEquals(expected, actual) Assert.areEqual(expected, actual) System.assert(condition) Assert.isTrue(condition) [SELECT ... WHERE ...] with no sharing context [SELECT ... WHERE ... WITH USER_MODE] Step 6 — PNB Test Coverage Checklist Every feature must be tested across all three paths. Missing any one of these is a quality failure: Positive Path Expected input → expected output. Assert the exact field values, record counts, or return values — not just that no exception was thrown. Negative Path Invalid input, null values, empty collections, and error conditions. Assert that exceptions are thrown with the correct type and message. Assert that no records were mutated when the operation should have failed cleanly. Bulk Path Insert/update/delete 200–251 records in a single test transaction. Assert that all records processed correctly — no partial failures from governor limits. Use Test.startTest() / Test.stopTest() to isolate governor limit counters for async work. Test Class Rules @isTest ( SeeAllData = false ) // Required — no exceptions without a documented reason private class AccountServiceTest { @TestSetup static void makeData ( ) { // Create all test data here — use a factory if one exists in the project } @isTest static void givenValidInput_whenProcessAccounts_thenFieldsUpdated ( ) { // Positive path List < Account

accounts

[ SELECT Id FROM Account LIMIT 10 ] ; Test . startTest ( ) ; AccountService . processAccounts ( accounts ) ; Test . stopTest ( ) ; // Assert meaningful outcomes — not just no exception List < Account

updated

[ SELECT Status__c FROM Account WHERE Id IN :accounts ] ; Assert . areEqual ( 'Processed' , updated [ 0 ] . Status__c , 'Status should be Processed' ) ; } } Step 7 — Trigger Architecture Checklist One trigger per object. If a second trigger exists, consolidate into the handler. Trigger body contains only: context checks, handler invocation, and routing logic. No business logic, SOQL, or DML directly in the trigger body. If a trigger framework (Trigger Actions Framework, ff-apex-common, custom base class) is already in use — extend it. Do not create a parallel pattern. Handler class is with sharing unless the trigger requires elevated access. Quick Reference — Hardcoded Anti-Patterns Summary Pattern Action SOQL inside for loop Refactor: query before the loop, operate on collections DML inside for loop Refactor: collect mutations, DML once after the loop Class missing sharing declaration Add with sharing (or document why without sharing ) escape="false" on user data (VF) Remove — auto-escaping enforces XSS prevention Empty catch block Add logging and appropriate re-throw or error handling String-concatenated SOQL with user input Replace with bind variable or whitelist validation Test with no assertion Add a meaningful Assert.* call System.assert / System.assertEquals style Upgrade to Assert.isTrue / Assert.areEqual Hardcoded record ID ( '001...' ) Replace with queried or inserted test record ID