@isTest
private class UpdateAccountCloseDealAmountTest {
    @isTest static void testUpdateAccountCloseDealAmount() {
        // Create test data
        Account acc = new Account(Name = 'Test Account');
        insert acc;
        
        Opportunity opp1 = new Opportunity(Name = 'Test Opp 1', AccountId = acc.Id, StageName = 'Closed Won', CloseDate = Date.today(), Amount = 100);
        Opportunity opp2 = new Opportunity(Name = 'Test Opp 2', AccountId = acc.Id, StageName = 'Closed Won', CloseDate = Date.today(), Amount = 200);
        insert new List<Opportunity>{opp1, opp2};
        
        // Execute batch job
        Test.startTest();
        Database.executeBatch(new UpdateAccountCloseDealAmount());
        Test.stopTest();
        
        // Verify results
        Account updatedAcc = [SELECT CloseDealAmount__c FROM Account WHERE Id = :acc.Id];
        System.assertEquals(200, updatedAcc.CloseDealAmount__c);
    }
}