public static void Assert(Expression<Func<bool>> predicate)
{
Visitor visitor = new Visitor();
Expression<Func<bool>> wrappedExpr = (Expression<Func<bool>>)visitor.Visit(predicate);
Func<bool> wrappedFunc = wrappedExpr.Compile();
if (!wrappedFunc())
throw ExceptionFactory.Make(visitor.Captures);
}
protected override Expression VisitBinary(BinaryExpression node)
{
Expression left = node.Left;
Expression right = node.Right;
Visitor leftVisitor = new Visitor();
Visitor rightVisitor = new Visitor();
BinaryExpression binaryExpression = Expression.MakeBinary(node.NodeType, leftVisitor.Visit(left), rightVisitor.Visit(right));
_captureNode.AddChild(leftVisitor.CaptureNode);
_captureNode.AddChild(rightVisitor.CaptureNode);
return WrapWithCapture(binaryExpression, node);
}
protected override Expression VisitMethodCall(MethodCallExpression node)
{
Expression instance = node.Object;
Visitor instanceVisitor = new Visitor();
List<Visitor> argumentVisitors = node.Arguments.Select(_ => new Visitor()).ToList();
Expression[] argumentExpressions = argumentVisitors.Zip(node.Arguments, (v, a) => v.Visit(a)).ToArray();
MethodCallExpression callExpression = node.Object == null
// static
? Expression.Call(node.Method, argumentExpressions)
// instance
: Expression.Call(instanceVisitor.Visit(instance), node.Method, argumentExpressions);
if (node.Object != null)
_captureNode.AddChild(instanceVisitor.CaptureNode);
foreach (Visitor visitor in argumentVisitors)
_captureNode.AddChild(visitor.CaptureNode);
return WrapWithCapture(callExpression, node);
}
protected override Expression VisitUnary(UnaryExpression node)
{
Expression operand = node.Operand;
Visitor visitor = new Visitor();
UnaryExpression unaryExpression = Expression.MakeUnary(node.NodeType, visitor.Visit(operand), operand.Type);
_captureNode.AddChild(visitor.CaptureNode);
return WrapWithCapture(unaryExpression, node);
}