What is the smoothest, most appealing syntax you've found for asserting parameter correctness in c#?

Question

A common problem in any language is to assert that parameters sent in to a method meet your requirements, and if they don\'t, to send nice, informative error messages. This

Answer 1

I tackled this exact problem a few weeks ago, after thinking that it is strange how testing libraries seem to need a million different versions of Assert to make their messages descriptive.

Here's my solution.

Brief summary - given this bit of code:

int x = 3;
string t = "hi";
Assert(() => 5*x + (2 / t.Length) < 99);

My Assert function can print out the following summary of what is passed to it:

(((5 * x) + (2 / t.Length)) < 99) == True where
{
  ((5 * x) + (2 / t.Length)) == 16 where
  {
    (5 * x) == 15 where
    {
      x == 3
    }
    (2 / t.Length) == 1 where
    {
      t.Length == 2 where
      {
        t == "hi"
      }
    }
  }
}

So all the identifier names and values, and the structure of the expression, could be included in the exception message, without you having to restate them in quoted strings.