/// <summary>
/// Prepares the mocks, dependencies and the item under test.
/// </summary>
/// <exception cref="LeapingGorilla.Testing.Exceptions.NoItemUnderTestException">Thrown if the user has specified [Dependency]'s but there is no [ItemUnderTest]</exception>
/// <exception cref="NoMatchingConstructorFoundException">Thrown if no constructor can be found on the [ItemUnderTest] that matches the number of [Dependency] fields/properties</exception>
/// <exception cref="DependencyMismatchException">Thrown if a [Dependency] cannot be found for a constructor parameter when one is expected.</exception>
/// <exception cref="NoItemUnderTestException">Thrown if there are fields/properties marked with [Dependency] but none with [ItemUnderTest]</exception>
private void PrepareMocksDependenciesAndItemUnderTest()
{
// Create a fast accessor onto the test class
var accessor = TypeAccessor.Create(GetType(), true);
// Get and validate the item under test
var itemUnderTest = GetPropertiesWithAttribute(typeof(ItemUnderTestAttribute)).Select(pi => new { Type = pi.PropertyType, pi.Name })
.Concat(GetFieldsWithAttribute(typeof(ItemUnderTestAttribute)).Select(pi => new { Type = pi.FieldType, pi.Name }))
.FirstOrDefault();
// Create mocks and dependencies
CreateManualDependencies();
var dependencies = CreateAndAssignPropertiesOrFieldsWithAttribute(accessor, typeof(DependencyAttribute));
dependencies.AddRange(CreateAndAssignPropertiesOrFieldsWithAttribute(accessor, typeof(NullDependencyAttribute)));
CreateAndAssignPropertiesOrFieldsWithAttribute(accessor, typeof(MockAttribute));
// It is invalid to have dependencies but no item under test
if (itemUnderTest == null)
{
if (dependencies.Count > 0)
{
throw new NoItemUnderTestException();
}
// No item under test but no dependencies. We can abort out of the rest of the setup
return;
}
// Determine the correct constructor for the item under test. If we cant match one then error out
var constructor = GetPreferredConstructor(itemUnderTest.Type, dependencies);
if (constructor == null)
{
throw new NoMatchingConstructorFoundException(dependencies);
}
var parameters = constructor.GetParameters();
var constructorArguments = new object[parameters.Length];
// Assign parameters. We remove them from the dependencies list as we go so we don't re-use dependencies in case of indirect (type only) matching
for (int index = 0; index < parameters.Length; index++)
{
var param = parameters[index];
var dep = dependencies.FirstOrDefault(d => d.Name == param.Name && d.Type == param.ParameterType) ?? dependencies.FirstOrDefault(d => d.Type == param.ParameterType);
if (dep == null)
{
throw new DependencyMismatchException(param.ParameterType, param.Name, index, parameters);
}
dependencies.Remove(dep);
constructorArguments[index] = dep.Value;
}
// Create the item under test and load it into the test class
accessor[this, itemUnderTest.Name] = Activator.CreateInstance(itemUnderTest.Type, constructorArguments);
}
private List <Dependency> CreateAndAssignPropertiesOrFieldsWithAttribute(TypeAccessor accessor, Type attributeType)
{
var dependencies = BuildDependenciesForPropertiesOrFieldsWithAttributeType(attributeType);
foreach (var dep in dependencies)
{
accessor[this, dep.Name] = dep.Value;
}
return(dependencies);
}
