From 5d1c77884f6686a59f121639dc177b7095e8c477 Mon Sep 17 00:00:00 2001
From: Jesse Plamondon-Willard <Pathoschild@users.noreply.github.com>
Date: Sat, 5 Sep 2020 13:37:40 -0400
Subject: add unit tests for PathUtilities, fix some edge cases

---
 src/SMAPI.Toolkit/Utilities/PathUtilities.cs | 43 ++++++++++++++++++++++++----
 1 file changed, 38 insertions(+), 5 deletions(-)

(limited to 'src/SMAPI.Toolkit/Utilities')

diff --git a/src/SMAPI.Toolkit/Utilities/PathUtilities.cs b/src/SMAPI.Toolkit/Utilities/PathUtilities.cs
index e9d71747..34940d4f 100644
--- a/src/SMAPI.Toolkit/Utilities/PathUtilities.cs
+++ b/src/SMAPI.Toolkit/Utilities/PathUtilities.cs
@@ -9,6 +9,13 @@ namespace StardewModdingAPI.Toolkit.Utilities
     /// <summary>Provides utilities for normalizing file paths.</summary>
     public static class PathUtilities
     {
+        /*********
+        ** Fields
+        *********/
+        /// <summary>The root prefix for a Windows UNC path.</summary>
+        private const string WindowsUncRoot = @"\\";
+
+
         /*********
         ** Accessors
         *********/
@@ -25,6 +32,7 @@ namespace StardewModdingAPI.Toolkit.Utilities
         /// <summary>Get the segments from a path (e.g. <c>/usr/bin/example</c> => <c>usr</c>, <c>bin</c>, and <c>example</c>).</summary>
         /// <param name="path">The path to split.</param>
         /// <param name="limit">The number of segments to match. Any additional segments will be merged into the last returned part.</param>
+        [Pure]
         public static string[] GetSegments(string path, int? limit = null)
         {
             return limit.HasValue
@@ -37,16 +45,28 @@ namespace StardewModdingAPI.Toolkit.Utilities
         [Pure]
         public static string NormalizePathSeparators(string path)
         {
-            string[] parts = PathUtilities.GetSegments(path);
-            string normalized = string.Join(PathUtilities.PreferredPathSeparator, parts);
-            if (path.StartsWith(PathUtilities.PreferredPathSeparator))
-                normalized = PathUtilities.PreferredPathSeparator + normalized; // keep root slash
+            string normalized = string.Join(PathUtilities.PreferredPathSeparator, PathUtilities.GetSegments(path));
+
+            // keep root
+#if SMAPI_FOR_WINDOWS
+            if (path.StartsWith(PathUtilities.WindowsUncRoot))
+                normalized = PathUtilities.WindowsUncRoot + normalized;
+            else
+#endif
+            if (path.StartsWith(PathUtilities.PreferredPathSeparator) || path.StartsWith(PathUtilities.WindowsUncRoot))
+                normalized = PathUtilities.PreferredPathSeparator + normalized;
+
             return normalized;
         }
 
-        /// <summary>Get a directory or file path relative to a given source path.</summary>
+        /// <summary>Get a directory or file path relative to a given source path. If no relative path is possible (e.g. the paths are on different drives), an absolute path is returned.</summary>
         /// <param name="sourceDir">The source folder path.</param>
         /// <param name="targetPath">The target folder or file path.</param>
+        /// <remarks>
+        ///
+        /// NOTE: this is a heuristic implementation that works in the cases SMAPI needs it for, but it doesn't handle all edge cases (e.g. case-sensitivity on Linux, or traversing between UNC paths on Windows). This should be replaced with the more comprehensive <c>Path.GetRelativePath</c> if the game ever migrates to .NET Core.
+        ///
+        /// </remarks>
         [Pure]
         public static string GetRelativePath(string sourceDir, string targetPath)
         {
@@ -58,13 +78,25 @@ namespace StardewModdingAPI.Toolkit.Utilities
 
             // get relative path
             string relative = PathUtilities.NormalizePathSeparators(Uri.UnescapeDataString(from.MakeRelativeUri(to).ToString()));
+
+            // set empty path to './'
             if (relative == "")
                 relative = "./";
+
+            // fix root
+            if (relative.StartsWith("file:") && !targetPath.Contains("file:"))
+            {
+                relative = relative.Substring("file:".Length);
+                if (targetPath.StartsWith(PathUtilities.WindowsUncRoot) && !relative.StartsWith(PathUtilities.WindowsUncRoot))
+                    relative = PathUtilities.WindowsUncRoot + relative.TrimStart('\\');
+            }
+
             return relative;
         }
 
         /// <summary>Get whether a path is relative and doesn't try to climb out of its containing folder (e.g. doesn't contain <c>../</c>).</summary>
         /// <param name="path">The path to check.</param>
+        [Pure]
         public static bool IsSafeRelativePath(string path)
         {
             if (string.IsNullOrWhiteSpace(path))
@@ -77,6 +109,7 @@ namespace StardewModdingAPI.Toolkit.Utilities
 
         /// <summary>Get whether a string is a valid 'slug', containing only basic characters that are safe in all contexts (e.g. filenames, URLs, etc).</summary>
         /// <param name="str">The string to check.</param>
+        [Pure]
         public static bool IsSlug(string str)
         {
             return !Regex.IsMatch(str, "[^a-z0-9_.-]", RegexOptions.IgnoreCase);
-- 
cgit