(GH-8) Add tests

Author: fwinkelbauer

Source/Cake.VsMetrics.Tests/VsMetricsRunnerFixture.cs

@@ -1,16 +1,26 @@
 using System.Collections.Generic;
+using Cake.Core;
 using Cake.Core.IO;
+using Cake.Testing;
 using Cake.Testing.Fixtures;
 
 namespace Cake.VsMetrics.Tests
 {
     internal sealed class VsMetricsRunnerFixture : ToolFixture<VsMetricsSettings>
     {
-        public VsMetricsRunnerFixture()
-            : base("metrics.exe")
+        public VsMetricsRunnerFixture(bool defaultToolExist = true, PlatformFamily platform = PlatformFamily.Windows)
+            : base("/Working/tools/metrics.exe")
         {
             InputFilePaths = new FilePath[] { "c:/tool.exe" };
             OutputFilePath = "metrics_result.xml";
+
+            if (defaultToolExist)
+            {
+                FileSystem.CreateFile("/Working/tools/metrics.exe");
+            }
+
+            Environment = new FakeEnvironment(platform);
+            Environment.WorkingDirectory = "/Working";
         }
 
         public IEnumerable<FilePath> InputFilePaths { get; set; }

Source/Cake.VsMetrics.Tests/VsMetricsRunnerTests.cs

@@ -59,5 +59,51 @@ public void RunFixtureWithSettings()
 
             Assert.AreEqual("/f:\"c:/tool.exe\" /o:\"/Working/metrics_result.xml\" /d:\"/Working\" /gac", result.Args);
         }
+
+        [TestMethod]
+        public void RunFixtureWithAlternativePathWindows()
+        {
+            AssertAlternativePath(VsMetricsToolVersion.Default, "/ProgramFilesX86/Microsoft Visual Studio 14.0/Team Tools/Static Analysis Tools/FxCop/metrics.exe");
+            AssertAlternativePath(VsMetricsToolVersion.VS2015, "/ProgramFilesX86/Microsoft Visual Studio 14.0/Team Tools/Static Analysis Tools/FxCop/metrics.exe");
+            AssertAlternativePath(VsMetricsToolVersion.VS2013, "/ProgramFilesX86/Microsoft Visual Studio 12.0/Team Tools/Static Analysis Tools/FxCop/metrics.exe");
+        }
+
+        [TestMethod]
+        [ExpectedException(typeof(CakeException))]
+        public void RunFixtureWithAlternativePathWindowsNotSupported()
+        {
+            var fixture = new VsMetricsRunnerFixture(false)
+            {
+                Settings = { ToolVersion = (VsMetricsToolVersion)1000 }
+            };
+
+            fixture.Environment.SetSpecialPath(SpecialPath.ProgramFilesX86, "/ProgramFilesX86");
+
+            fixture.Run();
+        }
+
+        [TestMethod]
+        [ExpectedException(typeof(CakeException))]
+        public void RunFixtureWithAlternativePathLinuxNotSupported()
+        {
+            var fixture = new VsMetricsRunnerFixture(false, PlatformFamily.Linux);
+
+            fixture.Run();
+        }
+
+        private void AssertAlternativePath(VsMetricsToolVersion version, string expectedPath)
+        {
+            var fixture = new VsMetricsRunnerFixture(false)
+            {
+                Settings = { ToolVersion = version }
+            };
+
+            fixture.FileSystem.CreateFile(expectedPath);
+            fixture.Environment.SetSpecialPath(SpecialPath.ProgramFilesX86, "/ProgramFilesX86");
+
+            var result = fixture.Run();
+
+            Assert.AreEqual(expectedPath, result.Path.FullPath);
+        }
     }
 }

Source/Cake.VsMetrics/VsMetricsRunner.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Linq;
 using Cake.Core;
 using Cake.Core.IO;
 using Cake.Core.Tooling;
@@ -76,7 +77,7 @@ protected override IEnumerable<FilePath> GetAlternativeToolPaths(VsMetricsSettin
         {
             if (_environment.Platform.IsUnix())
             {
-                return new FilePath[] { };
+                return Enumerable.Empty<FilePath>();
             }
 
             var programFiles = _environment.GetSpecialPath(SpecialPath.ProgramFilesX86);
@@ -96,7 +97,7 @@ protected override IEnumerable<FilePath> GetAlternativeToolPaths(VsMetricsSettin
                 return new FilePath[] { metrics2015 };
             }
 
-            return base.GetAlternativeToolPaths(settings);
+            return Enumerable.Empty<FilePath>();
         }
 
         private ProcessArgumentBuilder GetArguments(IEnumerable<FilePath> inputFilePaths, FilePath outputFilePath, VsMetricsSettings settings)