add descriptive error for PathTooLongException which crashes SMAPI or the installer

2 files changed, 26 insertions, 0 deletions

diff --git a/src/SMAPI.Toolkit/Properties/AssemblyInfo.cs b/src/SMAPI.Toolkit/Properties/AssemblyInfo.cs
index 233e680b..eede4562 100644
--- a/src/SMAPI.Toolkit/Properties/AssemblyInfo.cs
+++ b/src/SMAPI.Toolkit/Properties/AssemblyInfo.cs
@@ -1,4 +1,5 @@
 using System.Runtime.CompilerServices;
 
 [assembly: InternalsVisibleTo("StardewModdingAPI")]
+[assembly: InternalsVisibleTo("SMAPI.Installer")]
 [assembly: InternalsVisibleTo("SMAPI.Web")]
diff --git a/src/SMAPI.Toolkit/Utilities/PathUtilities.cs b/src/SMAPI.Toolkit/Utilities/PathUtilities.cs
index c9fb6213..a394edba 100644
--- a/src/SMAPI.Toolkit/Utilities/PathUtilities.cs
+++ b/src/SMAPI.Toolkit/Utilities/PathUtilities.cs
@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using System.Diagnostics.Contracts;
 using System.IO;
 using System.Linq;
@@ -133,5 +134,29 @@ namespace StardewModdingAPI.Toolkit.Utilities
         {
             return !Regex.IsMatch(str, "[^a-z0-9_.-]", RegexOptions.IgnoreCase);
         }
+
+        /// <summary>Get the paths which exceed the OS length limit.</summary>
+        /// <param name="rootPath">The root path to search.</param>
+        internal static IEnumerable<string> GetTooLongPaths(string rootPath)
+        {
+            return Directory
+                .EnumerateFileSystemEntries(rootPath, "*.*", SearchOption.AllDirectories)
+                .Where(PathUtilities.IsPathTooLong);
+        }
+
+        /// <summary>Get whether a file or directory path exceeds the OS path length limit.</summary>
+        /// <param name="path">The path to test.</param>
+        internal static bool IsPathTooLong(string path)
+        {
+            try
+            {
+                _ = Path.GetFullPath(path);
+                return false;
+            }
+            catch (PathTooLongException)
+            {
+                return true;
+            }
+        }
     }
 }