/// <summary>
/// Applies a step as part of the task to compare two objects for structural equality.
/// </summary>
/// <value>
/// Should return <c>true</c> if the subject matches the expectation or if no additional assertions
/// have to be executed. Should return <c>false</c> otherwise.
/// </value>
/// <remarks>
/// May throw when preconditions are not met or if it detects mismatching data.
/// </remarks>
public bool Handle(EquivalencyValidationContext context, IEquivalencyValidator parent, IEquivalencyAssertionOptions config)
{
Type subjectType = EnumerableEquivalencyStep.GetSubjectType(context, config);
Type[] interfaces = GetIEnumerableInterfaces(subjectType);
bool multipleInterfaces = (interfaces.Count() > 1);
if (multipleInterfaces)
{
IEnumerable <Type> enumerableTypes = interfaces.Select(
type => type.GetGenericArguments().Single());
AssertionScope.Current.FailWith(
String.Format(
"{{context:Subject}} is enumerable for more than one type. " +
"It is not known which type should be use for equivalence.{0}" +
"IEnumerable is implemented for the following types: {1}",
Environment.NewLine,
String.Join(", ", enumerableTypes)));
}
if (AssertExpectationIsCollection(context.Expectation))
{
var validator = new EnumerableEquivalencyValidator(parent, context)
{
Recursive = context.IsRoot || config.IsRecursive,
OrderingRules = config.OrderingRules
};
Type typeOfEnumeration = GetTypeOfEnumeration(subjectType);
Expression subjectToArray = ToArray(context.Subject, typeOfEnumeration);
Expression expectationToArray =
Expression.Constant(EnumerableEquivalencyStep.ToArray(context.Expectation));
MethodCallExpression executeExpression = Expression.Call(
Expression.Constant(validator),
"Execute",
new Type[] { typeOfEnumeration },
subjectToArray,
expectationToArray);
Expression.Lambda(executeExpression).Compile().DynamicInvoke();
}
return(true);
}
/// <summary>
/// Gets a value indicating whether this step can handle the verificationScope subject and/or expectation.
/// </summary>
public bool CanHandle(EquivalencyValidationContext context, IEquivalencyAssertionOptions config)
{
var subjectType = EnumerableEquivalencyStep.GetSubjectType(context, config);
return((context.Subject != null) && IsGenericCollection(subjectType));
}
