This repository demonstrates Apex Dependency Injection with a sample shipping service that allows to generate tracking numbers.
The sample shipping service provides two mock implementations: FedEx and DHL.
The service implementations are configured in a Service_Implementations__mdt custom metadata. The Shipping__c key of the custom metadata must map to a comma-delimited list of implementations such as DHL,FedEx.
The injector uses that list to load the service implementation classes with an Impl suffix (DHLImpl and FedExImpl).
The service can be accessed via the ShippingInjector class in two ways:
Option 1: Using the default implementation
// Get the first implementation configured in Service_Implementations__c custom metadata
ShippingService service = ShippingInjector.getDefaultService();
// Assuming that the default implementaiton is DHL
String trackingNumber = service.generateTrackingNumber(); // => DHL-XXXXOption 2: Using a specific implementation
// Get the FedEx implementation
ShippingService service = ShippingInjector.getService('FedEx');
String trackingNumber = service.generateTrackingNumber(); // => FEX-XXXXCheck out the ShippingTest test class for more details on how to use the service.
Create a scratch org:
sfdx force:org:create -a pattern -s -f config/project-scratch-def.json
Push source to scratch org:
sfdx force:source:push
Run Apex tests and get code coverage:
sfdx force:apex:test:run -c -r human -w 10