It is however netstandard2 and 'works on my machine'
Condition.Requires(id, nameof(id)).IsNotNull().AsWarning() Would log a warning to the logging pipeline; you would plug your own logging infrastructure into it to send it somewhere usefull. Likely be done inside an 'extension' library/package
Condition.Requires(id, nameof(id)).IsNotNull().Throws<MyAwesomeException>() Exception would have to have standard exception constructor (message[, inner])
CuttingEdge.Conditions is a library that helps developers to write pre- and postcondition validations in their C# 3.0 and VB.NET 9.0 code base. Writing these validations is easy and it improves the readability and maintainability of code.
CuttingEdge.Conditions is build up upon the new C# 3.0 and VB.NET 9.0 extension method mechanism and it allows you to validate arguments in a simple and fluent way. The following example gives a quick overview on the way you could write your pre- and postconditions.
C# example
public ICollection GetData(Nullable<int> id, string xml, IEnumerable<int> col)
{
// Check all preconditions:
Condition.Requires(id, nameof(id))
.IsNotNull() // throws ArgumentNullException on failure
.IsInRange(1, 999) // ArgumentOutOfRangeException on failure
.IsNotEqualTo(128); // throws ArgumentException on failure
Condition.Requires(xml, nameof(xml))
.StartsWith("<data>") // throws ArgumentException on failure
.EndsWith("</data>") // throws ArgumentException on failure
.Evaluate(xml.Contains("abc") || xml.Contains("cba")); // arg ex
Condition.Requires(col, nameof(col))
.IsNotNull() // throws ArgumentNullException on failure
.IsEmpty() // throws ArgumentException on failure
.Evaluate(c => c.Contains(id.Value) || c.Contains(0)); // arg ex
// Do some work
// Example: Call a method that should not return null
object result = BuildResults(xml, col);
// Check all postconditions:
Condition.Ensures(result, nameof(result))
.IsOfType(typeof(ICollection)); // throws PostconditionException on failure
return (ICollection)result;
}
public static int[] Multiply(int[] left, int[] right)
{
Condition.Requires(left, nameof(left)).IsNotNull();
// You can add an optional description to each check
Condition.Requires(right, nameof(right))
.IsNotNull()
.HasLength(left.Length, "left and right should have the same length");
// Do multiplication
}VB.NET example
Public Function GetData(ByVal id As Integer?, ByVal xml As String, _
ByVal col As ICollection) As ICollection
' Check all preconditions:
Condition.Requires(id, nameof(id)).IsNotNull().IsInRange(1, 999).IsNotEqualTo(128)
Condition.Requires(xml, nameof(xml)).StartsWith("<data>").EndsWith("</data>")
Condition.Requires(col, nameof(col)).IsNotNull().IsEmpty()
' Do some work
' Example: Call a method that should not return null
Dim result = BuildResults(xml, col)
' Check all postconditions:
Condition.Ensures(result, "result").IsOfType(GetType(ICollection))
Return result
End Function
Public Shared Function Multiply(left As Integer(), right As Integer()) As Integer()
left.Requires("left").IsNotNull()
' You can add an optional description to each check
right.Requires("right").IsNotNull() _
.HasLength(left.Length, "left and right should have the same length")
' Do multiplication
End FunctionThe previous example showed some important features of the library. The example showed the library's ability to:
Condition.Requires;Condition.Ensures;Note: A particular validation is executed immediately when it's method is called, and therefore all checks are executed in the order in which they are written.
CuttingEdge Conditions is available as NuGet package. If you're not using NuGet, please follow the steps below, to start using CuttingEdge.Conditions:
CuttingEdge.Conditions namespace at the top of a source file and use the 'requires' and 'ensures' code snippets to start writing pre- and postconditions within your code.For more information on this project please visit the following blog post or wiki page: