Opens up for more control of the exception being produced (#153)

Replaces #116

src/projects/EnsureThat/Ensure.cs

@@ -7,7 +7,10 @@ namespace EnsureThat
 {
     public static class Ensure
     {
-        internal static readonly ExceptionFactory ExceptionFactory = new ExceptionFactory();
+        /// <summary>
+        /// Gets or Sets the Exception factory to use.
+        /// </summary>
+        public static IExceptionFactory ExceptionFactory { get; set; } = new ExceptionFactory();
 
         /// <summary>
         /// Ensures for objects.
@@ -76,7 +79,7 @@ public static class Ensure
         /// <param name="optsFn"></param>
         /// <returns></returns>
         [Pure]
-        public static Param<T> That<T>([NoEnumeration]T value, string name = null, OptsFn optsFn = null)
+        public static Param<T> That<T>([NoEnumeration] T value, string name = null, OptsFn optsFn = null)
             => new Param<T>(name, value, optsFn);
 
         /// <summary>
@@ -90,7 +93,7 @@ public static Param<T> That<T>([NoEnumeration]T value, string name = null, OptsF
         /// <param name="optsFn"></param>
         /// <returns></returns>
         [Pure]
-        public static StringParam That([NoEnumeration]string value, string name = null, OptsFn optsFn = null)
+        public static StringParam That([NoEnumeration] string value, string name = null, OptsFn optsFn = null)
             => new StringParam(name, value, optsFn);
 
         /// <summary>
@@ -122,4 +125,4 @@ public static TypeParam ThatTypeFor<T>([NotNull] T value, string name = null, Op
         public static TypeParam ThatType([NotNull] Type value, string name = null, OptsFn optsFn = null)
             => new TypeParam(name, value, optsFn);
     }
-}
+}

src/projects/EnsureThat/EnsureOptions.cs

@@ -2,23 +2,42 @@
 
 namespace EnsureThat
 {
+    public delegate Exception CustomExceptionFactory(string message, string paramName);
+
     public struct EnsureOptions
     {
         /// <summary>
-        /// If defined, this exception will be thrown instead of the
-        /// standard exceptions for the particular ensure method.
+        /// If defined, this factory will be used to produce the exception that
+        /// will be thrown instead of the standard exceptions for the particular
+        /// ensure method.
+        /// Assign using <see cref="WithExceptionFactory"/>.
+        /// </summary>
+        public CustomExceptionFactory CustomExceptionFactory { get; private set; }
+
+        /// <summary>
+        /// If defined, and no <see cref="CustomExceptionFactory"/> has been defined,
+        /// this exception will be thrown instead of the standard exceptions for the
+        /// particular ensure method.
         /// Assign using <see cref="WithException"/>.
         /// </summary>
         public Exception CustomException { get; private set; }
 
         /// <summary>
-        /// If defined, and no <see cref="CustomException"/> has been defined,
+        /// If defined, and neither <see cref="CustomExceptionFactory"/>
+        /// nor <see cref="CustomException"/> has been defined,
         /// this message will be used instead of the standard message for the
         /// particular ensure method.
         /// Assign using <see cref="WithMessage"/>.
         /// </summary>
         public string CustomMessage { get; private set; }
 
+        public EnsureOptions WithExceptionFactory(CustomExceptionFactory factory)
+        {
+            CustomExceptionFactory = factory;
+
+            return this;
+        }
+
         public EnsureOptions WithException(Exception ex)
         {
             CustomException = ex;
@@ -33,4 +52,4 @@ public EnsureOptions WithMessage(string message)
             return this;
         }
     }
-}
+}

src/projects/EnsureThat/Internals/ExceptionFactory.cs

@@ -3,11 +3,11 @@
 
 namespace EnsureThat.Internals
 {
-    internal sealed class ExceptionFactory
+    internal sealed class ExceptionFactory : IExceptionFactory
     {
         [NotNull]
         [Pure]
-        internal Exception ArgumentException([NotNull] string defaultMessage, string paramName, OptsFn optsFn = null)
+        public Exception ArgumentException(string defaultMessage, string paramName, OptsFn optsFn = null)
         {
             if (optsFn != null)
             {
@@ -25,12 +25,15 @@ internal Exception ArgumentException([NotNull] string defaultMessage, string par
 
         [NotNull]
         [Pure]
-        internal Exception ArgumentNullException([NotNull] string defaultMessage, string paramName, OptsFn optsFn = null)
+        public Exception ArgumentNullException(string defaultMessage, string paramName, OptsFn optsFn = null)
         {
             if (optsFn != null)
             {
                 var opts = optsFn(new EnsureOptions());
 
+                if (opts.CustomExceptionFactory != null)
+                    return opts.CustomExceptionFactory(defaultMessage, paramName);
+
                 if (opts.CustomException != null)
                     return opts.CustomException;
 
@@ -43,7 +46,7 @@ internal Exception ArgumentNullException([NotNull] string defaultMessage, string
 
         [NotNull]
         [Pure]
-        internal Exception ArgumentOutOfRangeException<TValue>([NotNull] string defaultMessage, string paramName, TValue value, OptsFn optsFn = null)
+        public Exception ArgumentOutOfRangeException<TValue>(string defaultMessage, string paramName, TValue value, OptsFn optsFn = null)
         {
             if (optsFn != null)
             {
@@ -59,4 +62,4 @@ internal Exception ArgumentOutOfRangeException<TValue>([NotNull] string defaultM
             return new ArgumentOutOfRangeException(paramName, value, defaultMessage);
         }
     }
-}
+}

src/projects/EnsureThat/Internals/IExceptionFactory.cs

@@ -0,0 +1,12 @@
+using System;
+using JetBrains.Annotations;
+
+namespace EnsureThat.Internals
+{
+    public interface IExceptionFactory
+    {
+        Exception ArgumentException([NotNull] string defaultMessage, string paramName, OptsFn optsFn = null);
+        Exception ArgumentNullException([NotNull] string defaultMessage, string paramName, OptsFn optsFn = null);
+        Exception ArgumentOutOfRangeException<TValue>([NotNull] string defaultMessage, string paramName, TValue value, OptsFn optsFn = null);
+    }
+}

src/tests/UnitTests/OptsTests.cs

@@ -10,6 +10,44 @@ namespace UnitTests
 {
     public class OptsTests
     {
+        public class WithCustomExceptionFactoryTests : UnitTestBase
+        {
+            [Fact]
+            public void ThrowsTheCustomExceptionFromTheFactory()
+            {
+                object value = null;
+                OptsFn options = o => o.WithExceptionFactory((_, __) => new KeyNotFoundException());
+
+                var actions = new Action[]
+                {
+                    () => Ensure.Any.IsNotNull(value, ParamName, options),
+                    () => EnsureArg.IsNotNull(value, ParamName, options),
+                    () => Ensure.That(value, ParamName, options).IsNotNull()
+                }.ToList();
+
+                actions.ForEach(a => a.Should().Throw<KeyNotFoundException>());
+            }
+
+            [Fact]
+            public void WhenWithMessageAndCustomExceptionAreSpecified_ThrowsTheCustomExceptionFromTheFactory()
+            {
+                object value = null;
+                OptsFn options = o => o
+                    .WithMessage("Foo bar")
+                    .WithException(new KeyNotFoundException())
+                    .WithExceptionFactory((_, __) => new InvalidTimeZoneException());
+
+                var actions = new Action[]
+                {
+                    () => Ensure.Any.IsNotNull(value, ParamName, options),
+                    () => EnsureArg.IsNotNull(value, ParamName, options),
+                    () => Ensure.That(value, ParamName,options).IsNotNull()
+                }.ToList();
+
+                actions.ForEach(a => a.Should().Throw<InvalidTimeZoneException>().And.Message.Should().NotContain("Foo Bar"));
+            }
+        }
+
         public class WithExceptionTests : UnitTestBase
         {
             [Fact]
@@ -60,4 +98,4 @@ public void ThrowsExceptionWithTheCustomMessage()
             }
         }
     }
-}
+}

src/tests/UnitTests/UnitTests.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>net452;netcoreapp2.1;netcoreapp3.1;net5.0</TargetFrameworks>
+    <TargetFrameworks>net452;netcoreapp3.1;net5.0</TargetFrameworks>
     <IsPackable>false</IsPackable>
     <IsTestProject>true</IsTestProject>
   </PropertyGroup>