Refactor Ysfo, move IsPathValid method to PathHelper class

src/Ysfo.Core/Loaders/PathHelper.cs

@@ -82,5 +82,37 @@ public static String ConvertLstEntryToNative(String lstEntry, char directorySepa
                     throw new ArgumentException("Unknown DirectorySeparatorChar `" + directorySeparatorChar + "'.");
             }
         }
+
+        public const String WindowsExecutable = "fsmain.exe";
+        public const String LinuxExecutable = "ysflight";
+
+        /// <summary>
+        /// Checks whether <paramref name="ysPath"/> is a valid YsFlight directory.
+        /// </summary>
+        /// <param name="ysPath">The path to the YsFlight base directory.</param>
+        /// <returns><code>true</code> if <paramref name="ysPath"/> is valid.</returns>
+        public static Boolean IsPathValid(String ysPath)
+        {
+            // check path is not null
+            if (ysPath == null)
+            {
+                return false;
+            }
+
+            // check directory
+            if (!Directory.Exists(ysPath))
+            {
+                return false;
+            }
+
+            // check ysflight exectutable
+            if (!File.Exists(Path.Combine(ysPath, WindowsExecutable)) && !File.Exists(Path.Combine(ysPath, LinuxExecutable)))
+            {
+                return false;
+            }
+
+            // yay
+            return true;
+        }
     }
 }

src/Ysfo.Core/Ysfo.cs

@@ -19,34 +19,12 @@ public void Dispose()
         }
 
         /// <summary>
-        /// Checks whether Path is a valid ysflight directory.
+        /// Checks whether Path is a valid YsFlight directory.
         /// </summary>
-        /// <returns>true is Path is valid.</returns>
+        /// <returns><code>true</code> if Path is valid.</returns>
         public Boolean IsPathValid()
         {
-            // check path is not null
-            if (Path == null)
-            {
-                return false;
-            }
-
-            // check directory
-            if (!Directory.Exists(Path))
-            {
-                return false;
-            }
-
-            String windowsYsFlight = "fsmain.exe";
-            String linuxYsFlight = "ysflight";
-
-            // check ysflight exectutable
-            if (!File.Exists(System.IO.Path.Combine(Path, windowsYsFlight)) && !File.Exists(System.IO.Path.Combine(Path, linuxYsFlight)))
-            {
-                return false;
-            }
-
-            // yay
-            return true;
+            return Loaders.PathHelper.IsPathValid(Path);
         }
 
         /// <summary>

tests/Ysfo.Tests.Core/Loaders/PathHelperFixture.cs

@@ -1,8 +1,5 @@
 using System;
-using System.Collections.Generic;
 using System.IO;
-using System.Linq;
-using System.Text;
 using NUnit.Framework;
 using Ysfo.Core.Loaders;
 
@@ -32,7 +29,7 @@ public void GetFullPathThrowsExceptionIfRelPathIsNull()
         [ExpectedException(typeof(DirectoryNotFoundException))]
         public void GetFullPathThrowsExceptionIfYsPathIsInvalid()
         {
-            String invalidYsPath = System.IO.Path.Combine(_validYsPath, "invaliddir");
+            String invalidYsPath = Path.Combine(_validYsPath, "invaliddir");
 
             PathHelper.GetFullPath(invalidYsPath, _validLstPath);
         }
@@ -72,5 +69,44 @@ public void ConvertLstEntryIsCorrectForBackSlashDirectorySeperatorChar()
 
             Assert.AreEqual("aircraft\\aircraft.lst", result);
         }
+
+        [Test]
+        public void IsPathValidReturnsFalseIfYsPathIsNull()
+        {
+            Boolean result = PathHelper.IsPathValid(null);
+
+            Assert.IsFalse(result);
+        }
+
+        [Test]
+        public void IsPathValidReturnsFalseIfYsFlightExecutableDoesntExist()
+        {
+            Boolean result = PathHelper.IsPathValid(_validYsPath);
+
+            Assert.IsFalse(result);
+        }
+
+        [Test]
+        public void IsPathValidReturnsTrueIfValid()
+        {
+            String ysExecutable = Path.Combine(_validYsPath, PathHelper.WindowsExecutable);
+
+            // create file
+            File.Create(ysExecutable).Close();
+            Assert.IsTrue(File.Exists(ysExecutable), "Temporary executable not created!");
+
+            Boolean result = PathHelper.IsPathValid(_validYsPath);
+
+            try
+            {
+                Assert.IsTrue(result);
+            }
+            finally
+            {
+                // cleanup
+                File.Delete(ysExecutable);
+                Assert.IsFalse(File.Exists(ysExecutable), "Temporary executable not removed!");
+            }
+        }
     }
 }