Apex - 测试

测试是Apex或任何其他应用程序开发的集成部分。在Apex中，我们有单独的测试类来开发所有的单元测试。

测试类

在SFDC中，代码必须具有75％的代码覆盖率才能部署到生产。此代码覆盖率由测试类执行。测试类是测试其他Apex类的功能的代码片段。

让我们为我们之前编写的一个代码编写一个测试类。我们将编写测试类来覆盖我们的Trigger和Helper类代码。下面是需要覆盖的触发器和帮助类。

//Trigger with Helper Class
trigger Customer_After_Insert on APEX_Customer__c (after update) {
    CustomerTriggerHelper.createInvoiceRecords(Trigger.new, trigger.oldMap);//Trigger calls the helper class and does not have any code in Trigger
}

//Helper Class:
public class CustomerTriggerHelper {
    public static void createInvoiceRecords (List<apex_customer__c> customerList, Map<id, apex_customer__c> oldMapCustomer) {
        List<apex_invoice__c> InvoiceList = new List<apex_invoice__c>();
        for (APEX_Customer__c objCustomer: customerList) {
            if (objCustomer.APEX_Customer_Status__c == 'Active' && oldMapCustomer.get(objCustomer.id).APEX_Customer_Status__c == 'Inactive') {//condition to check the old value and new value
                APEX_Invoice__c objInvoice = new APEX_Invoice__c();
                objInvoice.APEX_Status__c = 'Pending';
 objInvoice.APEX_Customer__c = objCustomer.id;
                InvoiceList.add(objInvoice);
            }
        }
        insert InvoiceList;//DML to insert the Invoice List in SFDC
    }
}

创建测试类

数据创建

我们需要在测试类本身创建测试类的数据。默认情况下，测试类不能访问组织数据，但是如果您设置@isTest（seeAllData = true），那么它将有权访问组织的数据。

@isTest注释

通过使用此注释，您声明这是一个测试类，它不会被计入组织的总代码限制。

TestMethod关键字

单元测试方法是不带参数，不向数据库提交数据，不发送电子邮件，并在方法定义中使用testMethod关键字或isTest注释声明的方法。此外，测试方法必须在测试类中定义，即用isTest注释的类。

在我们的例子中，我们将看到，'myUnitTest'是我们的测试方法。

Test.startTest（）和Test.stopTest（）

这些是可用于测试类的标准测试方法。这些方法包含我们将模拟我们的测试的事件或动作。就像在这个例子中，我们将测试我们的触发器和帮助类来模拟火灾触发器，通过更新记录，我们已经做了开始和停止块。这也为在开始和停止块中的代码提供单独的调节器限制。

System.assert（）

此方法用实际检查所需的输出。在这种情况下，我们期望插入一个发票记录，所以我们添加了assert来检查。

例如：

/**
 * This class contains unit tests for validating the behavior of Apex classes
 * and triggers.
 *
 * Unit tests are class methods that verify whether a particular piece
 * of code is working properly. Unit test methods take no arguments,
 * commit no data to the database, and are flagged with the testMethod
 * keyword in the method definition.
 *
 * All test methods in an organization are executed whenever Apex code is deployed
 * to a production organization to confirm correctness, ensure code
 * coverage, and prevent regressions. All Apex classes are
 * required to have at least 75% code coverage in order to be deployed
 * to a production organization. In addition, all triggers must have some code coverage.
 * 
 * The @isTest class annotation indicates this class only contains test
 * methods. Classes defined with the @isTest annotation do not count against
 * the organization size limit for all Apex scripts.
 *
 * See the Apex Language Reference for more information about Testing and Code Coverage.
 */
@isTest
private class CustomerTriggerTestClass {
    static testMethod void myUnitTest() {
        //Create Data for Customer Objet
        
        APEX_Customer__c objCust = new APEX_Customer__c();
        objCust.Name = 'Test Customer';
        objCust.APEX_Customer_Status__c = 'Inactive';
        insert objCust;
        
        //Now, our trigger will fire on After update event so update the Records
        Test.startTest();//Starts the scope of test
        objCust.APEX_Customer_Status__c  = 'Active';
        update objCust;
        Test.stopTest();//Ends the scope of test
        
        //Now check if it is giving desired results using system.assert Statement.New invoice should be created
        List<apex_invoice__c> invList = [SELECT Id, APEX_Customer__c FROM APEX_Invoice__c WHERE APEX_Customer__c = :objCust.id];
        system.assertEquals(1,invList.size());//Check if one record is created in Invoivce sObject
    }
}