Apexテストクラスの作成とテストの実施方法【サンプルコードあり】

trigger Product2Trigger on Product2 (before insert) {
    
    for(Product2 p : trigger.new){
        if(String.isNotBlank(p.Name)){
            if(p.Name == 'Strawberry'){
                p.Color__c = 'Red';
            }else if(p.Name == 'Banana'){
                p.Color__c = 'Yellow';
            }else{
                p.Color__c = 'Other';
            }
        }
    }
}

@isTest(SeeAllData=false) /** 1 **/
public class Product2TriggerTest {

    @isTest /** 2 **/
    static void test01(){
        //Create test data
        Product2 p = new Product2(Name = 'Strawberry');

        /** 3 **/
        Test.startTest();
        Insert p;
        Test.stopTest();
        
        //Check result
        Product2 result = [Select Id, Name, Color__c From Product2 Limit 1];
        /** 4 **/
        Assert.areEqual(result.Name, 'Strawberry'); 
        Assert.areEqual(result.Color__c, 'Red');        
    }
    
    @isTest
    static void test02(){
        //Create test data
        List<Product2> pList = new List<Product2>();
        pList.add(new Product2(Name = 'Strawberry'));
        pList.add(new Product2(Name = 'Banana'));
        pList.add(new Product2(Name = 'Orange'));

        Test.startTest();
        Insert pList;
        Test.stopTest();
        
        //Check result
        List<Product2> results = [Select Id, Name, Color__c From Product2];
        /** 5 **/
        Assert.areEqual(3, results.size());
        
        Boolean case1 = false;
        Boolean case2 = false;
        Boolean case3 = false;
        
        for(Product2 p : results){
            if(p.Name == 'Strawberry'){
                case1 = true;
                Assert.areEqual('Red', p.Color__c); 
            }else if(p.Name == 'Banana'){
                case2 = true;
                Assert.areEqual('Yellow', p.Color__c); 
            }else if(p.Name == 'Orange'){
                case3 = true;
                Assert.areEqual('Other', p.Color__c,); 
            }
        }
        
    /** 6 **/
		Assert.isTrue(case1 && case2 && case3);     
    }
    
    /** 7 **/
    @testSetUp
    static void testSetUp(){
        //Create test data
    }
}