Convert DocFX project into ASP.NET Core to simplify the local documentation testing

Description

A variable is optional for a catch block:

try
{
}
catch (Exception)
{
}

But the comparer assumes the variable is set when determining whether two catch blocks are equal and when calculating the hash code for a catch block.

To reproduce

// Same expression twice to evade reference equality check
var x = Expression.TryCatch(Expression.Empty(), Expression.Catch(typeof(Exception), Expression.Empty()));
var y = Expression.TryCatch(Expression.Empty(), Expression.Catch(typeof(Exception), Expression.Empty()));

AssertAreEqual(x, y);

Resolution

These are the offending assumptions:

Replacing EqualsParameter and GetHashCodeParameter with Equals and GetHashCode respectively solves the problem.

Comparing x to x: