The following triggers and test class make up the shipping invoice example application:
trigger calculate on Item__c (after insert, after update, after delete) { // Use a map because it doesn't allow duplicate values Map<ID, Shipping_Invoice__C> updateMap = new Map<ID, Shipping_Invoice__C>(); // Set this integer to -1 if we are deleting Integer subtract ; // Populate the list of items based on trigger type List<Item__c> itemList; if(trigger.isInsert || trigger.isUpdate){ itemList = Trigger.new; subtract = 1; } else if(trigger.isDelete) { // Note -- there is no trigger.new in delete itemList = trigger.old; subtract = -1; } // Access all the information we need in a single query // rather than querying when we need it. // This is a best practice for bulkifying requests set<Id> AllItems = new set<id>(); for(item__c i :itemList){ // Assert numbers are not negative. // None of the fields would make sense with a negative value System.assert(i.quantity__c > 0, 'Quantity must be positive'); System.assert(i.weight__c >= 0, 'Weight must be non-negative'); System.assert(i.price__c >= 0, 'Price must be non-negative'); // If there is a duplicate Id, it won't get added to a set AllItems.add(i.Shipping_Invoice__C); } // Accessing all shipping invoices associated with the items in the trigger List<Shipping_Invoice__C> AllShippingInvoices = [SELECT Id, ShippingDiscount__c, SubTotal__c, TotalWeight__c, Tax__c, GrandTotal__c FROM Shipping_Invoice__C WHERE Id IN :AllItems]; // Take the list we just populated and put it into a Map. // This will make it easier to look up a shipping invoice // because you must iterate a list, but you can use lookup for a map, Map<ID, Shipping_Invoice__C> SIMap = new Map<ID, Shipping_Invoice__C>(); for(Shipping_Invoice__C sc : AllShippingInvoices) { SIMap.put(sc.id, sc); } // Process the list of items if(Trigger.isUpdate) { // Treat updates like a removal of the old item and addition of the // revised item rather than figuring out the differences of each field // and acting accordingly. // Note updates have both trigger.new and trigger.old for(Integer x = 0; x < Trigger.old.size(); x++) { Shipping_Invoice__C myOrder; myOrder = SIMap.get(trigger.old[x].Shipping_Invoice__C); // Decrement the previous value from the subtotal and weight. myOrder.SubTotal__c -= (trigger.old[x].price__c * trigger.old[x].quantity__c); myOrder.TotalWeight__c -= (trigger.old[x].weight__c * trigger.old[x].quantity__c); // Increment the new subtotal and weight. myOrder.SubTotal__c += (trigger.new[x].price__c * trigger.new[x].quantity__c); myOrder.TotalWeight__c += (trigger.new[x].weight__c * trigger.new[x].quantity__c); } for(Shipping_Invoice__C myOrder : AllShippingInvoices) { // Set tax rate to 9.25% Please note, this is a simple example. // Generally, you would never hard code values. // Leveraging Custom Settings for tax rates is a best practice. // See Custom Settings in the Apex Developer's guide // for more information. myOrder.Tax__c = myOrder.Subtotal__c * .0925; // Reset the shipping discount myOrder.ShippingDiscount__c = 0; // Set shipping rate to 75 cents per pound. // Generally, you would never hard code values. // Leveraging Custom Settings for the shipping rate is a best practice. // See Custom Settings in the Apex Developer's guide // for more information. myOrder.Shipping__c = (myOrder.totalWeight__c * .75); myOrder.GrandTotal__c = myOrder.SubTotal__c + myOrder.tax__c + myOrder.Shipping__c; updateMap.put(myOrder.id, myOrder); } } else { for(Item__c itemToProcess : itemList) { Shipping_Invoice__C myOrder; // Look up the correct shipping invoice from the ones we got earlier myOrder = SIMap.get(itemToProcess.Shipping_Invoice__C); myOrder.SubTotal__c += (itemToProcess.price__c * itemToProcess.quantity__c * subtract); myOrder.TotalWeight__c += (itemToProcess.weight__c * itemToProcess.quantity__c * subtract); } for(Shipping_Invoice__C myOrder : AllShippingInvoices) { // Set tax rate to 9.25% Please note, this is a simple example. // Generally, you would never hard code values. // Leveraging Custom Settings for tax rates is a best practice. // See Custom Settings in the Apex Developer's guide // for more information. myOrder.Tax__c = myOrder.Subtotal__c * .0925; // Reset shipping discount myOrder.ShippingDiscount__c = 0; // Set shipping rate to 75 cents per pound. // Generally, you would never hard code values. // Leveraging Custom Settings for the shipping rate is a best practice. // See Custom Settings in the Apex Developer's guide // for more information. myOrder.Shipping__c = (myOrder.totalWeight__c * .75); myOrder.GrandTotal__c = myOrder.SubTotal__c + myOrder.tax__c + myOrder.Shipping__c; updateMap.put(myOrder.id, myOrder); } } // Only use one DML update at the end. // This minimizes the number of DML requests generated from this trigger. update updateMap.values(); }
trigger ShippingDiscount on Shipping_Invoice__C (before update) { // Free shipping on all orders greater than $100 for(Shipping_Invoice__C myShippingInvoice : Trigger.new) { if((myShippingInvoice.subtotal__c >= 100.00) && (myShippingInvoice.ShippingDiscount__c == 0)) { myShippingInvoice.ShippingDiscount__c = myShippingInvoice.Shipping__c * -1; myShippingInvoice.GrandTotal__c += myShippingInvoice.ShippingDiscount__c; } } }
@IsTest private class TestShippingInvoice{ // Test for inserting three items at once public static testmethod void testBulkItemInsert(){ // Create the shipping invoice. It's a best practice to either use defaults // or to explicitly set all values to zero so as to avoid having // extraneous data in your test. Shipping_Invoice__C order1 = new Shipping_Invoice__C(subtotal__c = 0, totalweight__c = 0, grandtotal__c = 0, ShippingDiscount__c = 0, Shipping__c = 0, tax__c = 0); // Insert the order and populate with items insert Order1; List<Item__c> list1 = new List<Item__c>(); Item__c item1 = new Item__C(Price__c = 10, weight__c = 1, quantity__c = 1, Shipping_Invoice__C = order1.id); Item__c item2 = new Item__C(Price__c = 25, weight__c = 2, quantity__c = 1, Shipping_Invoice__C = order1.id); Item__c item3 = new Item__C(Price__c = 40, weight__c = 3, quantity__c = 1, Shipping_Invoice__C = order1.id); list1.add(item1); list1.add(item2); list1.add(item3); insert list1; // Retrieve the order, then do assertions order1 = [SELECT id, subtotal__c, tax__c, shipping__c, totalweight__c, grandtotal__c, shippingdiscount__c FROM Shipping_Invoice__C WHERE id = :order1.id]; System.assert(order1.subtotal__c == 75, 'Order subtotal was not $75, but was '+ order1.subtotal__c); System.assert(order1.tax__c == 6.9375, 'Order tax was not $6.9375, but was ' + order1.tax__c); System.assert(order1.shipping__c == 4.50, 'Order shipping was not $4.50, but was ' + order1.shipping__c); System.assert(order1.totalweight__c == 6.00, 'Order weight was not 6 but was ' + order1.totalweight__c); System.assert(order1.grandtotal__c == 86.4375, 'Order grand total was not $86.4375 but was ' + order1.grandtotal__c); System.assert(order1.shippingdiscount__c == 0, 'Order shipping discount was not $0 but was ' + order1.shippingdiscount__c); } // Test for updating three items at once public static testmethod void testBulkItemUpdate(){ // Create the shipping invoice. It's a best practice to either use defaults // or to explicitly set all values to zero so as to avoid having // extraneous data in your test. Shipping_Invoice__C order1 = new Shipping_Invoice__C(subtotal__c = 0, totalweight__c = 0, grandtotal__c = 0, ShippingDiscount__c = 0, Shipping__c = 0, tax__c = 0); // Insert the order and populate with items. insert Order1; List<Item__c> list1 = new List<Item__c>(); Item__c item1 = new Item__C(Price__c = 1, weight__c = 1, quantity__c = 1, Shipping_Invoice__C = order1.id); Item__c item2 = new Item__C(Price__c = 2, weight__c = 2, quantity__c = 1, Shipping_Invoice__C = order1.id); Item__c item3 = new Item__C(Price__c = 4, weight__c = 3, quantity__c = 1, Shipping_Invoice__C = order1.id); list1.add(item1); list1.add(item2); list1.add(item3); insert list1; // Update the prices on the 3 items list1[0].price__c = 10; list1[1].price__c = 25; list1[2].price__c = 40; update list1; // Access the order and assert items updated order1 = [SELECT id, subtotal__c, tax__c, shipping__c, totalweight__c, grandtotal__c, shippingdiscount__c FROM Shipping_Invoice__C WHERE Id = :order1.Id]; System.assert(order1.subtotal__c == 75, 'Order subtotal was not $75, but was '+ order1.subtotal__c); System.assert(order1.tax__c == 6.9375, 'Order tax was not $6.9375, but was ' + order1.tax__c); System.assert(order1.shipping__c == 4.50, 'Order shipping was not $4.50, but was ' + order1.shipping__c); System.assert(order1.totalweight__c == 6.00, 'Order weight was not 6 but was ' + order1.totalweight__c); System.assert(order1.grandtotal__c == 86.4375, 'Order grand total was not $86.4375 but was ' + order1.grandtotal__c); System.assert(order1.shippingdiscount__c == 0, 'Order shipping discount was not $0 but was ' + order1.shippingdiscount__c); } // Test for deleting items public static testmethod void testBulkItemDelete(){ // Create the shipping invoice. It's a best practice to either use defaults // or to explicitly set all values to zero so as to avoid having // extraneous data in your test. Shipping_Invoice__C order1 = new Shipping_Invoice__C(subtotal__c = 0, totalweight__c = 0, grandtotal__c = 0, ShippingDiscount__c = 0, Shipping__c = 0, tax__c = 0); // Insert the order and populate with items insert Order1; List<Item__c> list1 = new List<Item__c>(); Item__c item1 = new Item__C(Price__c = 10, weight__c = 1, quantity__c = 1, Shipping_Invoice__C = order1.id); Item__c item2 = new Item__C(Price__c = 25, weight__c = 2, quantity__c = 1, Shipping_Invoice__C = order1.id); Item__c item3 = new Item__C(Price__c = 40, weight__c = 3, quantity__c = 1, Shipping_Invoice__C = order1.id); Item__c itemA = new Item__C(Price__c = 1, weight__c = 3, quantity__c = 1, Shipping_Invoice__C = order1.id); Item__c itemB = new Item__C(Price__c = 1, weight__c = 3, quantity__c = 1, Shipping_Invoice__C = order1.id); Item__c itemC = new Item__C(Price__c = 1, weight__c = 3, quantity__c = 1, Shipping_Invoice__C = order1.id); Item__c itemD = new Item__C(Price__c = 1, weight__c = 3, quantity__c = 1, Shipping_Invoice__C = order1.id); list1.add(item1); list1.add(item2); list1.add(item3); list1.add(itemA); list1.add(itemB); list1.add(itemC); list1.add(itemD); insert list1; // Seven items are now in the shipping invoice. // The following deletes four of them. List<Item__c> list2 = new List<Item__c>(); list2.add(itemA); list2.add(itemB); list2.add(itemC); list2.add(itemD); delete list2; // Retrieve the order and verify the deletion order1 = [SELECT id, subtotal__c, tax__c, shipping__c, totalweight__c, grandtotal__c, shippingdiscount__c FROM Shipping_Invoice__C WHERE Id = :order1.Id]; System.assert(order1.subtotal__c == 75, 'Order subtotal was not $75, but was '+ order1.subtotal__c); System.assert(order1.tax__c == 6.9375, 'Order tax was not $6.9375, but was ' + order1.tax__c); System.assert(order1.shipping__c == 4.50, 'Order shipping was not $4.50, but was ' + order1.shipping__c); System.assert(order1.totalweight__c == 6.00, 'Order weight was not 6 but was ' + order1.totalweight__c); System.assert(order1.grandtotal__c == 86.4375, 'Order grand total was not $86.4375 but was ' + order1.grandtotal__c); System.assert(order1.shippingdiscount__c == 0, 'Order shipping discount was not $0 but was ' + order1.shippingdiscount__c); } // Testing free shipping public static testmethod void testFreeShipping(){ // Create the shipping invoice. It's a best practice to either use defaults // or to explicitly set all values to zero so as to avoid having // extraneous data in your test. Shipping_Invoice__C order1 = new Shipping_Invoice__C(subtotal__c = 0, totalweight__c = 0, grandtotal__c = 0, ShippingDiscount__c = 0, Shipping__c = 0, tax__c = 0); // Insert the order and populate with items. insert Order1; List<Item__c> list1 = new List<Item__c>(); Item__c item1 = new Item__C(Price__c = 10, weight__c = 1, quantity__c = 1, Shipping_Invoice__C = order1.id); Item__c item2 = new Item__C(Price__c = 25, weight__c = 2, quantity__c = 1, Shipping_Invoice__C = order1.id); Item__c item3 = new Item__C(Price__c = 40, weight__c = 3, quantity__c = 1, Shipping_Invoice__C = order1.id); list1.add(item1); list1.add(item2); list1.add(item3); insert list1; // Retrieve the order and verify free shipping not applicable order1 = [SELECT id, subtotal__c, tax__c, shipping__c, totalweight__c, grandtotal__c, shippingdiscount__c FROM Shipping_Invoice__C WHERE Id = :order1.Id]; // Free shipping not available on $75 orders System.assert(order1.subtotal__c == 75, 'Order subtotal was not $75, but was '+ order1.subtotal__c); System.assert(order1.tax__c == 6.9375, 'Order tax was not $6.9375, but was ' + order1.tax__c); System.assert(order1.shipping__c == 4.50, 'Order shipping was not $4.50, but was ' + order1.shipping__c); System.assert(order1.totalweight__c == 6.00, 'Order weight was not 6 but was ' + order1.totalweight__c); System.assert(order1.grandtotal__c == 86.4375, 'Order grand total was not $86.4375 but was ' + order1.grandtotal__c); System.assert(order1.shippingdiscount__c == 0, 'Order shipping discount was not $0 but was ' + order1.shippingdiscount__c); // Add items to increase subtotal item1 = new Item__C(Price__c = 25, weight__c = 20, quantity__c = 1, Shipping_Invoice__C = order1.id); insert item1; // Retrieve the order and verify free shipping is applicable order1 = [SELECT id, subtotal__c, tax__c, shipping__c, totalweight__c, grandtotal__c, shippingdiscount__c FROM Shipping_Invoice__C WHERE Id = :order1.Id]; // Order total is now at $100, so free shipping should be enabled System.assert(order1.subtotal__c == 100, 'Order subtotal was not $100, but was '+ order1.subtotal__c); System.assert(order1.tax__c == 9.25, 'Order tax was not $9.25, but was ' + order1.tax__c); System.assert(order1.shipping__c == 19.50, 'Order shipping was not $19.50, but was ' + order1.shipping__c); System.assert(order1.totalweight__c == 26.00, 'Order weight was not 26 but was ' + order1.totalweight__c); System.assert(order1.grandtotal__c == 109.25, 'Order grand total was not $86.4375 but was ' + order1.grandtotal__c); System.assert(order1.shippingdiscount__c == -19.50, 'Order shipping discount was not -$19.50 but was ' + order1.shippingdiscount__c); } // Negative testing for inserting bad input public static testmethod void testNegativeTests(){ // Create the shipping invoice. It's a best practice to either use defaults // or to explicitly set all values to zero so as to avoid having // extraneous data in your test. Shipping_Invoice__C order1 = new Shipping_Invoice__C(subtotal__c = 0, totalweight__c = 0, grandtotal__c = 0, ShippingDiscount__c = 0, Shipping__c = 0, tax__c = 0); // Insert the order and populate with items. insert Order1; Item__c item1 = new Item__C(Price__c = -10, weight__c = 1, quantity__c = 1, Shipping_Invoice__C = order1.id); Item__c item2 = new Item__C(Price__c = 25, weight__c = -2, quantity__c = 1, Shipping_Invoice__C = order1.id); Item__c item3 = new Item__C(Price__c = 40, weight__c = 3, quantity__c = -1, Shipping_Invoice__C = order1.id); Item__c item4 = new Item__C(Price__c = 40, weight__c = 3, quantity__c = 0, Shipping_Invoice__C = order1.id); try{ insert item1; } catch(Exception e) { system.assert(e.getMessage().contains('Price must be non-negative'), 'Price was negative but was not caught'); } try{ insert item2; } catch(Exception e) { system.assert(e.getMessage().contains('Weight must be non-negative'), 'Weight was negative but was not caught'); } try{ insert item3; } catch(Exception e) { system.assert(e.getMessage().contains('Quantity must be positive'), 'Quantity was negative but was not caught'); } try{ insert item4; } catch(Exception e) { system.assert(e.getMessage().contains('Quantity must be positive'), 'Quantity was zero but was not caught'); } } }