/// <summary>
/// Returns the current service provider with mock service registrations for the specified test host service provider
/// </summary>
/// <param name="serviceProvider">Test host service provider</param>
/// <returns></returns>
public static IServiceProvider GetCurrentScopeServiceProvider(this IServiceProvider serviceProvider)
{
var currentScope = NestedServiceScope.GetCurrentScopeByServiceProvider(serviceProvider);
return(currentScope == null ? serviceProvider : currentScope.ServiceProvider);
}
/// <summary>
/// Decorate service registrations to allow local mock service registrations inside tests without rebuilding the DI-container
/// This method should be called the last for the test host after all required service configuration calls.
/// That's the reason why it returns void and not IServiceCollection, there aren't supposed to be any additional calls after that.
/// </summary>
/// <param name="services"></param>
/// <param name="decorationCriteria">The criteria whether the given service should be decorated for possible local mock registrations</param>
public static void DecorateServicesForTesting(this IServiceCollection services, Func <Type, bool> decorationCriteria)
{
if (services == null)
{
throw new ArgumentNullException(nameof(services));
}
if (decorationCriteria == null)
{
throw new ArgumentNullException(nameof(decorationCriteria));
}
//Register root service collection to be able to determine the current mock scope later on
services.AddSingleton(services);
services.Remove(new ServiceDescriptor(typeof(IOptions <>), typeof(OptionsManager <>),
ServiceLifetime.Singleton));
services.Remove(new ServiceDescriptor(typeof(IOptionsSnapshot <>), typeof(OptionsManager <>),
ServiceLifetime.Scoped));
services.Remove(new ServiceDescriptor(typeof(IOptionsMonitor <>), typeof(OptionsMonitor <>),
ServiceLifetime.Singleton));
var configureOptions = services.Where(s => s.ServiceType.IsClosedTypeOf(typeof(IConfigureOptions <>)))
.ToArray();
var existingOptionsRegistrations = services.Where(s => s.ServiceType.IsClosedTypeOf(typeof(IOptions <>))).ToArray();
var existingOptionsSnapshotRegistrations = services.Where(s => s.ServiceType.IsClosedTypeOf(typeof(IOptionsSnapshot <>))).ToArray();
var existingOptionsMonitorRegistrations = services.Where(s => s.ServiceType.IsClosedTypeOf(typeof(IOptionsMonitor <>))).ToArray();
foreach (var configureOption in configureOptions)
{
var optionsType = configureOption.ServiceType.GenericTypeArguments[0];
var optionsClosedGenericType = typeof(IOptions <>).MakeGenericType(optionsType);
var optionsSnapshotClosedGenericType = typeof(IOptionsSnapshot <>).MakeGenericType(optionsType);
var optionsMonitorClosedGenericType = typeof(IOptionsMonitor <>).MakeGenericType(optionsType);
if (existingOptionsRegistrations.All(s => s.ServiceType != optionsClosedGenericType))
{
services.AddSingleton(optionsClosedGenericType,
typeof(OptionsManager <>).MakeGenericType(optionsType));
}
if (existingOptionsSnapshotRegistrations.All(s => s.ServiceType != optionsSnapshotClosedGenericType))
{
services.AddScoped(optionsSnapshotClosedGenericType,
typeof(OptionsManager <>).MakeGenericType(optionsType));
}
if (existingOptionsMonitorRegistrations.All(s => s.ServiceType != optionsMonitorClosedGenericType))
{
services.AddSingleton(optionsMonitorClosedGenericType,
typeof(OptionsMonitor <>).MakeGenericType(optionsType));
}
}
var newServices = new ServiceCollection();
foreach (var wrappedServiceDescriptor in services)
{
Func <IServiceProvider, object> objectFactory = serviceProvider =>
{
var currentScope = NestedServiceScope.GetCurrentScopeByRootServices(services);
if (currentScope == null)
{
return(serviceProvider.CreateInstance(wrappedServiceDescriptor));
}
var serviceDescriptor =
currentScope.GetClosestServiceDefinition(wrappedServiceDescriptor.ServiceType);
return(serviceDescriptor == null
? serviceProvider.CreateInstance(wrappedServiceDescriptor)
: serviceProvider.CreateInstance(serviceDescriptor));
};
if (decorationCriteria(wrappedServiceDescriptor.ServiceType))
{
//We can't mock classes and open-generic interfaces
if (wrappedServiceDescriptor.ServiceType.IsClass ||
wrappedServiceDescriptor.ServiceType.IsGenericType &&
wrappedServiceDescriptor.ServiceType.ContainsGenericParameters)
{
newServices.Add(wrappedServiceDescriptor);
}
else
{
//We change decorated services Singleton lifetimes to Scoped to make mocked registrations local
//to a concrete mock scope
var serviceLifetime = wrappedServiceDescriptor.Lifetime == ServiceLifetime.Singleton
? ServiceLifetime.Scoped
: wrappedServiceDescriptor.Lifetime;
newServices.Add(ServiceDescriptor.Describe(wrappedServiceDescriptor.ServiceType, objectFactory, serviceLifetime));
}
}
else
{
newServices.Add(wrappedServiceDescriptor);
}
}
services.Clear();
services.Add(newServices);
}
public NestedServiceProvider(IServiceProvider rootServiceProvider, NestedServiceScope nestedServiceScope)
{
RootServiceProvider = rootServiceProvider;
NestedServiceScope = nestedServiceScope;
}