Testing Best Practices and Examples

0-ApexTestingBestPractices.md

This Gist shows code examples for Apex Testing Best Practices. It relys on having the TestFactory in your org.

01-MyApexClass.java

public with sharing class MyApexClass {

	// This method will be used to demonstrate a positive test
	public static String doSomethingAwesome() {
		return doSomethingAwesome(false);
	}

	// This method will be used to demostrate how to test a thrown exception
	public static String doSomethingAwesome(Boolean throwException) {
		if (throwException) {
			throw new MyApexClassException('Something bad happened');
		}
		return 'Awesome';
	}

	// This method will be used to demonstrate how to test database queries
	public static Account queryAccount() {
		return [SELECT Name FROM Account LIMIT 1];
	}

	// This annotation makes a normally private method visible to unit tests
	@TestVisible 
	private static String privateAwesome() {
		return 'Still Awesome';
	}

	public class MyApexClassException extends Exception {}
}

02-MyApexClassTest.java

@isTest
private class MyApexClassTest {
	
	// This test shows a postive path.
	@isTest static void verifyAwesome() {
		System.assertEquals('Awesome', MyApexClass.doSomethingAwesome(), 'The awesome method was not so awesome.');
	}

	// This test shows how to cause an exception to be thrown and catch it.
	@isTest static void exceptAwesome() {
		try {
			MyApexClass.doSomethingAwesome(true);
		} catch (MyApexClass.MyApexClassException e) {
			return;
		}
		System.assert(false, 'A MyApexClassException was expected, but not thrown.');
	}

	// This test shows how to setup test data to be used in your methods.
	@isTest static void queryAccountTest() {
		Account a = (Account) TestFactory.createSObject(new Account());
		insert a;

		Test.startTest(); // Resets all limits (DML, SOQL, etc)
		Account testAccount = MyApexClass.queryAccount();
		Test.stopTest();

		System.assertEquals(a.Name, testAccount.Name, 'The wrong account was returned.');
	}

	// This test is calling a private method decorated with @TestVisible
	@isTest static void verifyPrivateAwesome() {
		System.assertEquals('Still Awesome', MyApexClass.privateAwesome());
	}
	
}

03-DemoContactTrigger.java

trigger DemoContactTrigger on Contact (before insert) {

	// Bulk version 
	/*
	List<Id> acctIds = new List<Id>();
	for (Contact c : Trigger.New) {
		if (c.AccountId != null) {
			acctIds.add(c.AccountId);
		}
	}

	Map<Id, Account> acctMap = new Map<Id, Account>([SELECT Id, Account_Email__c FROM Account where Id in :acctIds]);

	for (Contact c : Trigger.New) {
		if (c.Email == null && c.AccountId != null) {
			c.Email = acctMap.get(c.AccountId).Account_Email__c;
		}
	}
	*/

	// Non bulk version 
	for (Contact c : Trigger.New) {

		if (c.Email == null) {
		//if (c.Email == null && c.AccountId != null) {
			c.Email = [SELECT Account_Email__c FROM Account WHERE Id = :c.AccountId].Account_Email__c;
		}
	}

}

04-DemoContactTriggerTest.java

@isTest
private class DemoContactTriggerTest {
	
	@isTest static void insertSingleContactNoEmail() {
		Account a = (Account) TestFactory.createSObject(new Account(Account_Email__c = 'info@demo.com'));
		insert a;
		Contact c = (Contact) TestFactory.createSObject(new Contact(AccountId = a.Id));

		Test.startTest();
		insert c;
		Test.stopTest();

		Contact testContact = [SELECT Email from Contact where Id = :c.Id];
		System.assertEquals('info@demo.com', testContact.Email, 'The contact email should have been changed to the account email.');
	}

	@isTest static void insertSingleContactWithEmail() {
		Account a = (Account) TestFactory.createSObject(new Account(Account_Email__c = 'info@demo.com'));
		insert a;
		Contact c = (Contact) TestFactory.createSObject(new Contact(AccountId = a.Id, Email = 'something@demo.com'));

		Test.startTest();
		insert c;
		Test.stopTest();

		Contact testContact = [SELECT Email from Contact where Id = :c.Id];
		System.assertEquals('something@demo.com', testContact.Email, 'The contact email should not have been changed.');
	}

	@isTest static void insertPrivateContact() {
		Contact c = (Contact) TestFactory.createSObject(new Contact(Email = 'something@demo.com'));

		Test.startTest();
		insert c;
		Test.stopTest();

		Contact testContact = [SELECT Email from Contact where Id = :c.Id];
		System.assertEquals('something@demo.com', testContact.Email, 'The contact email should not have been changed.');
	}

	@isTest static void insertAccountNoEmail() {
		Account a = (Account) TestFactory.createSObject(new Account());
		insert a;
		Contact c = (Contact) TestFactory.createSObject(new Contact(AccountId = a.Id));

		Test.startTest();
		insert c;
		Test.stopTest();

		Contact testContact = [SELECT Email from Contact where Id = :c.Id];
		System.assertEquals(null, testContact.Email, 'There shouldn\'t be an email on the contact.');

	}
	
	@isTest static void insertBulkContact() {
		Account a = (Account) TestFactory.createSObject(new Account(Account_Email__c = 'info@demo.com'));
		insert a;
		List<Contact> testContacts = (List<Contact>) TestFactory.createSObjectList(new Contact(AccountId = a.Id), 200);

		Test.startTest();
        insert testContacts;
		Test.stopTest();

		for (Contact c : [SELECT Email FROM Contact WHERE Id in :testContacts]) {
			System.assertEquals('info@demo.com', c.Email, 'The contact email should have been changed to the account email.');
		}
	}
	
}

05-CalloutClass.java

public with sharing class CalloutClass {

	public static String doCallout() {
	    Http h = new Http();
	    HttpRequest req = new HttpRequest();
	    req.setEndpoint('https://api.endpoint.com/something');
	    req.setMethod('GET');
	    
	    HttpResponse res = h.send(req); 

	    return res.getBody();
	}
}

06-MockHttpResponse.java

@isTest
global class MockHttpResponse implements HttpCalloutMock {
	global HTTPResponse respond(HTTPRequest req) {
		HttpResponse res = new HttpResponse();
		res.setHeader('Content-Type', 'application/json');
		res.setStatusCode(200);
		res.setBody('A response');
		return res;
	}
}

07-CalloutClassTest.java

@isTest
private class CalloutClassTest {
	
	@isTest static void testCallOut() {
		Account a = (Account) TestFactory.createSObject(new Account());
		insert a;
		// We need to use startTest() to avoid an uncommitted work pending exception
		Test.startTest();
		Test.setMock(HttpCalloutMock.class, new MockHttpResponse());
		String response = CalloutClass.doCallout();
		Test.stopTest();
		System.assertEquals('A response', response);
	}
	
}

08-DemoControllerExtension.java

public with sharing class DemoControllerExtension {

	private final Account acct;

    public DemoControllerExtension(ApexPages.StandardController stdController) {
        this.acct = (Account)stdController.getRecord();
    }

    public String param {
        get {
            if (param == null) {
                param = ApexPages.currentPage().getParameters().get('param');
            }
            return param;
        }
        set;
    }

    public PageReference doSomething() {
        if (param == null) {
            ApexPages.addMessage(new ApexPages.Message(ApexPages.Severity.ERROR, 'No param provided'));
        }
        return null;
    }
}

09-DemoControllerPage.jsp

<apex:page standardController="Account" extensions="DemoControllerExtension">

	<apex:pageMessages />

	<apex:form>
		<apex:pageBlock>
			<apex:pageBlockButtons>
				<apex:commandButton action="{!doSomething}" value="Do Something" />
			</apex:pageBlockButtons>
			<apex:pageBlockSection columns="1">
				<apex:outputField value="{!Account.Name}" />
				<apex:pageBlockSectionItem>
					<apex:outputLabel value="Parameter" />
					<apex:outputText value="{!param}" />
				</apex:pageBlockSectionItem>
			</apex:pageBlockSection>
		</apex:pageBlock>
	</apex:form>
	
</apex:page>

10-DemoControllerExtenstionTest.java

@isTest
private class DemoControllerExtensionTest {

	private static Account testAccount;

	static {
		testAccount = (Account) TestFactory.createSObject(new Account());
		insert testAccount; 
	}
	
	@isTest static void checkErrorNoParam() {
	    	DemoControllerExtension testCtrl = new DemoControllerExtension(new ApexPages.StandardController(testAccount));
	    	testCtrl.doSomething();
	
	    	System.assert(!ApexPages.getMessages().isEmpty(), 'There should be an error displayed on the page that no parameter was given.');
	}

	@isTest static void checkParam() {
		ApexPages.CurrentPage().getParameters().put('param', testAccount.name);
	    	DemoControllerExtension testCtrl = new DemoControllerExtension(new ApexPages.StandardController(testAccount));
	    	testCtrl.doSomething();
	    	
	    	System.assertEquals(testAccount.name, testCtrl.param);
	    	System.assert(ApexPages.getMessages().isEmpty(), 'There should be no errors displayed on the page.');
	}
}

RunAsTest.java

@isTest
private class RunAsTest {
    
    @isTest static void mixedDml() {
        Profile p = [select id from profile where name='Standard User'];

        User u = new User(alias = 'standt', email='standarduser@testorg.com', 
                emailencodingkey='UTF-8', lastname='Testing', 
                languagelocalekey='en_US', 
                localesidkey='en_US', profileid = p.Id,
                timezonesidkey='America/Los_Angeles', 
                username='standarduser3234234@testorg.com');
        insert u;


        Group g = new Group();
        g.Name = 'Test Group';
        g.DeveloperName = 'TestGroup';
        insert g;

        GroupMember gm = new GroupMember();
        gm.GroupId = g.Id;
        gm.UserOrGroupId = u.Id;
        insert gm;

        // If you don't use runAs here, you will get a mixed DML exception
        System.runAs(u) {
        	Account a = new Account();
        	a.Name = 'Test Account';
        	insert a;
        }
    }
}