GH-2297 - Extended NUnit3Settings to support alternative app.config f…

…iles

- Modified NUnit3Settings class to support new ConfigurationFile property that maps to --configfile=app.config for the nunit-console runner
- In the 3.8.0 release of the nunit-console runner, a new command line argument was added that supports loading the app.config file from an alternative path or file.
- Here is the new 3.8.0 feature: nunit/nunit-console#246

src/Cake.Common.Tests/Unit/Tools/NUnit/NUnit3RunnerTests.cs

@@ -244,6 +244,7 @@ public void Should_Set_Commandline_Switches()
                 fixture.Settings.ShadowCopy = true;
                 fixture.Settings.Agents = 3;
                 fixture.Settings.TraceLevel = NUnitInternalTraceLevel.Debug;
+                fixture.Settings.ConfigurationFile = "app.config";
                 fixture.Settings.Params = new Dictionary<string, string>
                 {
                     ["one"] = "1",
@@ -266,6 +267,7 @@ public void Should_Set_Commandline_Switches()
                         "--dispose-runners --shadowcopy --agents=3 " +
                         "--process=InProcess --domain=Single " +
                         "--trace=verbose " +
+                        "\"--configfile=/Working/app.config\" " +
                         "\"--params=one=1\" " +
                         "\"--params=two=2\" " +
                         "\"--params=three=3\"", result.Args);

src/Cake.Common/Tools/NUnit/NUnit3Runner.cs

@@ -226,6 +226,11 @@ private ProcessArgumentBuilder GetArguments(IEnumerable<FilePath> assemblyPaths,
                 builder.Append("--trace=" + settings.TraceLevel.Value.GetArgumentValue());
             }
 
+            if (settings.ConfigurationFile != null)
+            {
+                builder.AppendQuoted(string.Format(CultureInfo.InvariantCulture, "--configfile={0}", settings.ConfigurationFile.MakeAbsolute(_environment).FullPath));
+            }
+
             if (settings.Params != null && settings.Params.Count > 0)
             {
                 foreach (var param in settings.Params)

src/Cake.Common/Tools/NUnit/NUnit3Settings.cs

@@ -246,6 +246,12 @@ public sealed class NUnit3Settings : ToolSettings
         /// </value>
         public int? Agents { get; set; }
 
+        /// <summary>
+        /// Gets or sets a value indicating the path to an alternative app.config file to load.
+        /// </summary>
+        /// <value>The location that NUnit should load an alternative app.config file from.</value>
+        public FilePath ConfigurationFile { get; set; }
+
         /// <summary>
         /// Gets or sets the parameters that should be passed to the runner.
         /// </summary>