Specialized Exception types

src/Squirrel/ExceptionTypes.cs

@@ -0,0 +1,50 @@
+using System;
+
+namespace Squirrel
+{
+    /// <inheritdoc />
+    /// <summary>
+    /// Base class for Squirrel-originated exceptions.
+    /// </summary>
+    public abstract class SquirrelBaseException: Exception
+    {
+        protected SquirrelBaseException(string message)
+            : base(message)
+        {
+        }
+    }
+
+    /// <summary>
+    /// Thrown when no Releases folder or RELEASES file is found at the specified location.
+    /// </summary>
+    public class SquirrelReleasesMissingException : SquirrelBaseException
+    {
+        public SquirrelReleasesMissingException(string message) 
+            : base(message)
+        {
+        }
+    }
+
+    /// <summary>
+    /// Thrown when the Releases\RELEASES file is empty or corrupt.
+    /// </summary>
+    public class SquirrelReleasesCorruptException: SquirrelBaseException
+    {
+        public SquirrelReleasesCorruptException(string message) 
+            : base(message)
+        {
+        }
+    }
+
+    /// <summary>
+    /// Thrown when Update.exe isn't found in the expected location.
+    /// </summary>
+    /// <remarks>See https://github.com/Squirrel/Squirrel.Windows/blob/master/docs/using/debugging-updates.md for more information.</remarks>
+    public class SquirrelNoUpdateException: SquirrelBaseException
+    {
+        public SquirrelNoUpdateException(string message) 
+            : base(message)
+        {
+        }
+    }
+}

src/Squirrel/Squirrel.csproj

@@ -84,6 +84,7 @@
     <Compile Include="ContentType.cs" />
     <Compile Include="DeltaPackage.cs" />
     <Compile Include="EnumerableExtensions.cs" />
+    <Compile Include="ExceptionTypes.cs" />
     <Compile Include="FileDownloader.cs" />
     <Compile Include="IUpdateManager.cs" />
     <Compile Include="MarkdownSharp.cs" />

src/Squirrel/UpdateManager.CheckForUpdates.cs

@@ -97,7 +97,7 @@ public async Task<UpdateInfo> CheckForUpdate(
                             "The directory {0} does not exist, something is probably broken with your application",
                             updateUrlOrPath);
 
-                        throw new Exception(message);
+                        throw new SquirrelReleasesMissingException(message);
                     }
 
                     var fi = new FileInfo(Path.Combine(updateUrlOrPath, "RELEASES"));
@@ -110,7 +110,7 @@ public async Task<UpdateInfo> CheckForUpdate(
 
                         var packages = (new DirectoryInfo(updateUrlOrPath)).GetFiles("*.nupkg");
                         if (packages.Length == 0) {
-                            throw new Exception(message);
+                            throw new SquirrelReleasesMissingException(message);
                         }
 
                         // NB: Create a new RELEASES file since we've got a directory of packages
@@ -127,7 +127,7 @@ public async Task<UpdateInfo> CheckForUpdate(
                 progress(66);
 
                 if (!remoteReleases.Any()) {
-                    throw new Exception("Remote release File is empty or corrupted");
+                    throw new SquirrelReleasesCorruptException("Remote release File is empty or corrupted");
                 }
 
                 ret = determineUpdateInfo(intention, localReleases, remoteReleases, ignoreDeltaUpdates);
@@ -154,7 +154,7 @@ UpdateInfo determineUpdateInfo(UpdaterIntention intention, IEnumerable<ReleaseEn
 
                 if (remoteReleases == null) {
                     this.Log().Warn("Release information couldn't be determined due to remote corrupt RELEASES file");
-                    throw new Exception("Corrupt remote RELEASES file");
+                    throw new SquirrelReleasesCorruptException("Corrupt remote RELEASES file");
                 }
 
                 var latestFullRelease = Utility.FindCurrentVersion(remoteReleases);

src/Squirrel/UpdateManager.cs

@@ -310,7 +310,7 @@ static string getUpdateExe()
             var updateDotExe = Path.Combine(Path.GetDirectoryName(assembly.Location), "..\\Update.exe");
             var target = new FileInfo(updateDotExe);
 
-            if (!target.Exists) throw new Exception("Update.exe not found, not a Squirrel-installed app?");
+            if (!target.Exists) throw new SquirrelNoUpdateException("Update.exe not found, not a Squirrel-installed app?");
             return target.FullName;
         }
     }