Add CSharpCodeMatcher (#324)

* wip

* fix

* .

* windows-2019

* <Target Name="CheckIfShouldKillVBCSCompiler" />

* <!--https://github.com/aspnet/RoslynCodeDomProvider/issues/51-->

* AllowCSharpCodeMatcher

* CSharpCodeMatcher : IObjectMatcher

* TemplateForIsMatchWithDynamic

* RequestMessageBodyMatcher_GetMatchingScore_BodyAsJson_CSharpCodeMatcher

* fix

*  }

* Better Exception Handling

src/WireMock.Net/Matchers/CSharpCodeMatcher.cs

@@ -0,0 +1,197 @@
+using System;
+using System.Linq;
+using JetBrains.Annotations;
+using Newtonsoft.Json.Linq;
+using WireMock.Exceptions;
+using WireMock.Validation;
+
+namespace WireMock.Matchers
+{
+    /// <summary>
+    /// CSharpCode / CS-Script Matcher
+    /// </summary>
+    /// <inheritdoc cref="IObjectMatcher"/>
+    /// <inheritdoc cref="IStringMatcher"/>
+    internal class CSharpCodeMatcher : IObjectMatcher, IStringMatcher
+    {
+        private const string TemplateForIsMatchWithString = "{0} public class CodeHelper {{ public bool IsMatch(string it) {{ {1} }} }}";
+
+        private const string TemplateForIsMatchWithDynamic = "{0} public class CodeHelper {{ public bool IsMatch(dynamic it) {{ {1} }} }}";
+
+        private readonly string[] _usings =
+        {
+            "System",
+            "System.Linq",
+            "System.Collections.Generic",
+            "Microsoft.CSharp",
+            "Newtonsoft.Json.Linq"
+        };
+
+        public MatchBehaviour MatchBehaviour { get; }
+
+        private readonly string[] _patterns;
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="CSharpCodeMatcher"/> class.
+        /// </summary>
+        /// <param name="patterns">The patterns.</param>
+        public CSharpCodeMatcher([NotNull] params string[] patterns) : this(MatchBehaviour.AcceptOnMatch, patterns)
+        {
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="CSharpCodeMatcher"/> class.
+        /// </summary>
+        /// <param name="matchBehaviour">The match behaviour.</param>
+        /// <param name="patterns">The patterns.</param>
+        public CSharpCodeMatcher(MatchBehaviour matchBehaviour, [NotNull] params string[] patterns)
+        {
+            Check.NotNull(patterns, nameof(patterns));
+
+            MatchBehaviour = matchBehaviour;
+            _patterns = patterns;
+        }
+
+        public double IsMatch(string input)
+        {
+            return IsMatchInternal(input);
+        }
+
+        public double IsMatch(object input)
+        {
+            return IsMatchInternal(input);
+        }
+
+        public double IsMatchInternal(object input)
+        {
+            double match = MatchScores.Mismatch;
+
+            if (input != null)
+            {
+                match = MatchScores.ToScore(_patterns.Select(pattern => IsMatch(input, pattern)));
+            }
+
+            return MatchBehaviourHelper.Convert(MatchBehaviour, match);
+        }
+
+        private bool IsMatch(dynamic input, string pattern)
+        {
+            bool isMatchWithString = input is string;
+            var inputValue = isMatchWithString ? input : JObject.FromObject(input);
+            string source = GetSourceForIsMatchWithString(pattern, isMatchWithString);
+
+            object result = null;
+
+#if NET451 || NET452
+            var compilerParams = new System.CodeDom.Compiler.CompilerParameters
+            {
+                GenerateInMemory = true,
+                GenerateExecutable = false,
+                ReferencedAssemblies =
+                {
+                    "System.dll",
+                    "System.Core.dll",
+                    "Microsoft.CSharp.dll",
+                    "Newtonsoft.Json.dll"
+                }
+            };
+
+            using (var codeProvider = new Microsoft.CSharp.CSharpCodeProvider())
+            {
+                var compilerResults = codeProvider.CompileAssemblyFromSource(compilerParams, source);
+
+                if (compilerResults.Errors.Count != 0)
+                {
+                    var errors = from System.CodeDom.Compiler.CompilerError er in compilerResults.Errors select er.ToString();
+                    throw new WireMockException(string.Join(", ", errors));
+                }
+
+                object helper = compilerResults.CompiledAssembly.CreateInstance("CodeHelper");
+                if (helper == null)
+                {
+                    throw new WireMockException("CSharpCodeMatcher: Unable to create instance from WireMock.CodeHelper");
+                }
+
+                var methodInfo = helper.GetType().GetMethod("IsMatch");
+                if (methodInfo == null)
+                {
+                    throw new WireMockException("CSharpCodeMatcher: Unable to find method 'IsMatch' in WireMock.CodeHelper");
+                }
+
+                try
+                {
+                    result = methodInfo.Invoke(helper, new[] { inputValue });
+                }
+                catch
+                {
+                    throw new WireMockException("CSharpCodeMatcher: Unable to call method 'IsMatch' in WireMock.CodeHelper");
+                }
+            }
+#elif NET46 || NET461
+            dynamic script;
+            try
+            {
+                script = CSScriptLibrary.CSScript.Evaluator.CompileCode(source).CreateObject("*");
+            }
+            catch
+            {
+                throw new WireMockException("CSharpCodeMatcher: Unable to create compiler for WireMock.CodeHelper");
+            }
+            
+            try
+            {
+                result = script.IsMatch(inputValue);
+            }
+            catch
+            {
+                throw new WireMockException("CSharpCodeMatcher: Problem calling method 'IsMatch' in WireMock.CodeHelper");
+            }
+#elif NETSTANDARD2_0
+            dynamic script;
+            try
+            {
+                var assembly = CSScriptLib.CSScript.Evaluator.CompileCode(source);
+                script = csscript.GenericExtensions.CreateObject(assembly, "*");
+            }
+            catch (Exception ex)
+            {
+                throw new WireMockException("CSharpCodeMatcher: Unable to compile code for WireMock.CodeHelper", ex);
+            }
+
+            try
+            {
+                result = script.IsMatch(inputValue);
+            }
+            catch (Exception ex)
+            {
+                throw new WireMockException("CSharpCodeMatcher: Problem calling method 'IsMatch' in WireMock.CodeHelper");
+            }
+#else
+            throw new NotSupportedException("The 'CSharpCodeMatcher' cannot be used in netstandard 1.3");
+#endif
+            try
+            {
+                return (bool)result;
+            }
+            catch
+            {
+                throw new WireMockException($"Unable to cast result '{result}' to bool");
+            }
+        }
+
+        private string GetSourceForIsMatchWithString(string pattern, bool isMatchWithString)
+        {
+            string template = isMatchWithString ? TemplateForIsMatchWithString : TemplateForIsMatchWithDynamic;
+            return string.Format(template, string.Join(Environment.NewLine, _usings.Select(u => $"using {u};")), pattern);
+        }
+
+        /// <inheritdoc cref="IStringMatcher.GetPatterns"/>
+        public string[] GetPatterns()
+        {
+            return _patterns;
+        }
+
+        /// <inheritdoc cref="IMatcher.Name"/>
+        public string Name => "CSharpCodeMatcher";
+    }
+}