From ef4442a002f9fdbfeafdee5b37416972336feb7d Mon Sep 17 00:00:00 2001
From: Eric Lloyd <ewlloyd@gmail.com>
Date: Fri, 14 Sep 2018 09:33:33 -0700
Subject: [PATCH] Specialized Exception types

---
 src/Squirrel/ExceptionTypes.cs                | 50 +++++++++++++++++++
 src/Squirrel/Squirrel.csproj                  |  1 +
 src/Squirrel/UpdateManager.CheckForUpdates.cs |  8 +--
 src/Squirrel/UpdateManager.cs                 |  2 +-
 4 files changed, 56 insertions(+), 5 deletions(-)
 create mode 100644 src/Squirrel/ExceptionTypes.cs

diff --git a/src/Squirrel/ExceptionTypes.cs b/src/Squirrel/ExceptionTypes.cs
new file mode 100644
index 000000000..2cd86bdb7
--- /dev/null
+++ b/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)
+        {
+        }
+    }
+}
diff --git a/src/Squirrel/Squirrel.csproj b/src/Squirrel/Squirrel.csproj
index 9769199ef..4fea080ad 100644
--- a/src/Squirrel/Squirrel.csproj
+++ b/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" />
diff --git a/src/Squirrel/UpdateManager.CheckForUpdates.cs b/src/Squirrel/UpdateManager.CheckForUpdates.cs
index 226494d30..9a4f63ac7 100644
--- a/src/Squirrel/UpdateManager.CheckForUpdates.cs
+++ b/src/Squirrel/UpdateManager.CheckForUpdates.cs
@@ -92,7 +92,7 @@ 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"));
@@ -105,7 +105,7 @@ 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
@@ -122,7 +122,7 @@ 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(localReleases, remoteReleases, ignoreDeltaUpdates);
@@ -149,7 +149,7 @@ UpdateInfo determineUpdateInfo(IEnumerable<ReleaseEntry> localReleases, IEnumera
 
                 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);
diff --git a/src/Squirrel/UpdateManager.cs b/src/Squirrel/UpdateManager.cs
index 6e9d59f59..13b47cad0 100644
--- a/src/Squirrel/UpdateManager.cs
+++ b/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;
         }
     }