Visualforce email template unit test - salesforce

Question

I have a trigger that sends an email using a VF template. I'm trying to write a unit test for that code, but keep running into a problem when trying to create the test data.
Here is my test method:
static TestMethod void testQuestionAttachment(){
Id profileId = SYSTEM_ADMIN_PROFILE_ID;
List<User> users = TestUtils.createUsers(profileId, 1);
insert users;
string templateText = '<messaging:emailTemplate subject="{!relatedTo.Name}" recipientType="User" relatedToType="Cutom_Object__c"><messaging:htmlEmailBody ><ul><li>test content</li></ul></messaging:htmlEmailBody></messaging:emailTemplate>';
EmailTemplate template = new EmailTemplate(
developerName = 'TestEmailVFTemplate',
TemplateType= 'visualforce',
FolderId = users[0].Id,
Name = 'TestEmailVFTemplate',
IsActive = true);
template.HtmlValue = templateText;
template.Body = templateText;
System.runAs(users[0]){
insert template;
}
...
And it fails with FIELD_INTEGRITY_EXCEPTION, <messaging:emailTemplate> is required and must be the outermost tag in the markup at line 1 column 1: [Markup].
I really don't understand why this isn't working. I must be missing something...

Answer 1

The issue is with your TemplateType = 'Visualforce'. Instead change it to template.Markup=templateText;. Markup field can be used to assign the body of visualforce template. I tried it in my test class.
Refer below example:
static #isTest void myTest () {
Profile pf = [SELECT Id,Name FROM Profile WHERE Name = 'System Administrator' LIMIT 1];
User usr = new User(
Alias = 'usralias',
Email = 'theuser#email.com',
Emailencodingkey = 'UTF-8',
Lastname = 'user_lastname',
Languagelocalekey = 'en_US',
Localesidkey = 'en_US',
Profileid = pf.Id,
Timezonesidkey = 'America/Los_Angeles',
Username = Math.random() + 'test#testuser.com',
CompanyName = 'the company',
UserRoleId='00E28000000zqCy'
);
insert usr;
string templateText = '<messaging:emailTemplate subject="{!relatedTo.Name}" recipientType="User" relatedToType="Custom_Object__c"><messaging:htmlEmailBody ><ul><li>test content</li></ul></messaging:htmlEmailBody></messaging:emailTemplate>';
EmailTemplate template = new EmailTemplate(DeveloperName = 'TestEmailVFTemplate', TemplateType= 'Visualforce', FolderId = UserInfo.getUserId(),
Name = 'TestEmailVFTemplate',
IsActive = true);
template.Markup=templateText;
System.runAs(usr){
insert template;
}
}