Writing Test class for Currency Conversion Trigger - triggers

Question

I need little assistance in writing a test class for this trigger that converts the record currency to org currency. Can anyone please assist/guide? Please.
trigger convertToEuro on CustomObject(before update) {
List<CurrencyType> currencyTypeList = [select id,IsoCode,ConversionRate from CurrencyType where isActive = true] ;
Map<String , Decimal> isoWithRateMap = new Map<String, Decimal>();
for(CurrencyType c : currencyTypeList) {
isoWithRateMap.put(c.IsoCode , c.ConversionRate) ;
}
for(CustomObject ce: trigger.new){
if(ce.CurrencyIsoCode != 'EUR' && isoWithRateMap.containsKey(ce.CurrencyIsoCode)){
ce.Amount_Converted__c = ce.ffps_iv__Amount__c/ isoWithRateMap.get(ce.CurrencyIsoCode);
}
}
}

Answer 1

#isTest(seealldata=false)
public class testConvertToEuro{
#testSetup
static void setupTest(){
List<CurrencyType> liCT = New List<CurrencyType>();
List<CustomObject> liCO = New List<CustomObject>();
Integer iCounter = 0;
liCT.add(new CurrencyType(IsoCode='EUR',ConversionRate=1,isActive=TRUE));
liCT.add(new CurrencyType(IsoCode='USD',ConversionRate=2,isActive=TRUE));
liCT.add(new CurrencyType(IsoCode='XXX',ConversionRate=3,isActive=TRUE));
liCT.add(new CurrencyType(IsoCode='YYY',ConversionRate=4,isActive=TRUE));
liCT.add(new CurrencyType(IsoCode='ZZZ',ConversionRate=5,isActive=TRUE));
for(Integer i=0; i<251; i++){
CustomObject co = New CustomObject(
CurrencyIsoCode = liCT[iCounter].IsoCode;
ffps_iv__Amount__c = liCT[iCounter].ConversionRate + .01;
);
if(iCounter < liCT.size() -1){
iCounter += 1;
}
else{
iCounter = 0;
}
}
insert liCT;
insert liCO;
}
static testmethod void runTest(){
setupTest();
List<CustomObject> liCustomObjectsToUpdate = New List<CustomObject>();
for(CustomObject co : [SELECT Id, ffps_iv__Amount__c, Amount_Converted__c from CustomObject]){
co.ffps_iv__Amount__c -= .01;
liCustomObjectsToUpdate.add(co);
}
test.startTest();
Update liCustomObjectsToUpdate;
test.stopTest();
System.assertEquals([SELECT Id, Amount_Converted__c FROM CustomObject LIMIT 1][0].Amount_Converted__c, 1);
}
}
I can't test this code without adding your custom object so it might have some errors. Please let me know what errors you are getting. If you want help debugging, you should provide the exact code being used and the exact error message.
It follows the basic pattern for testing update triggers:
Insert test data
Retrieve test data
Update records
Assert that the trigger generated the desired result