In salesforce Production/Developer edition test coverage shows only 13%.But same code in trail edition test coverage shows 88% And salesforce Production/Developer edition system.assert shows error "variable doesnot exist But in Trail edition no errror Code Visualforce page DocumentEmailer Apex class DocumentEmailController public with sharing class DocumentEmailController { public ID documentId {get;set;} public String email {get;set;} public List documents { get { if (documents == null) { documents = new List(); documents.add(new SelectOption('01570000001NZDn','Cup of Coffee? - DOC')); documents.add(new SelectOption('01570000001NZDi','Workflow Cheatsheet - PDF')); } return documents; } set; } public PageReference sendDoc() { Document doc = [select id, name, body, contenttype, developername, type from Document where id = :documentId]; Messaging.EmailFileAttachment attach = new Messaging.EmailFileAttachment(); attach.setContentType(doc.contentType); attach.setFileName(doc.developerName+'.'+doc.type); attach.setInline(false); attach.Body = doc.Body; Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage(); mail.setUseSignature(false); mail.setToAddresses(new String[] { email }); mail.setSubject('Document Email Demo'); mail.setHtmlBody('Here is the email you requested: '+doc.name); mail.setFileAttachments(new Messaging.EmailFileAttachment[] { attach }); // Send the email Messaging.sendEmail(new Messaging.SingleEmailMessage[] { mail }); ApexPages.addMessage(new ApexPages.Message(ApexPages.Severity.INFO, 'Email with Document sent to '+email)); return null; } } Test code Test_DocumentEmailer @isTest private class Test_DocumentEmailer { static Document document; static { document = new Document(); document.Body = Blob.valueOf('Some Text'); document.ContentType = 'application/pdf'; document.DeveloperName = 'my_document'; document.IsPublic = true; document.Name = 'My Document'; document.FolderId = [select id from folder where name = 'My Test Docs'].id; insert document; } static testMethod void testDocumentEmailer() { PageReference pref = Page.DocumentEmailer; DocumentEmailController con = new DocumentEmailController(); Test.startTest(); System.assertEquals(2,con.documents.size()); // populate the field with values con.documentId = document.id; con.email = 'test@noemail.com'; // submit the request pref = con.sendDoc(); Test.stopTest(); } } In test code System.assertEquals(2,con.documents.size()); shows error Variable doesnot exist documents