From 9a1dc32a11a9c0a0d59d6ecbea197daef4635904 Mon Sep 17 00:00:00 2001
From: Jason Nelson <jason@carbonmade.com>
Date: Thu, 9 Nov 2023 10:05:40 -0800
Subject: [PATCH] Improve nullability annotations

---
 src/Zio/FileSystemEntry.cs              | 2 +-
 src/Zio/FileSystems/MemoryFileSystem.cs | 9 ++++-----
 src/Zio/FileSystems/MountFileSystem.cs  | 6 +++---
 src/Zio/UPath.cs                        | 2 +-
 4 files changed, 9 insertions(+), 10 deletions(-)

diff --git a/src/Zio/FileSystemEntry.cs b/src/Zio/FileSystemEntry.cs
index aaf38b9..495f7d6 100644
--- a/src/Zio/FileSystemEntry.cs
+++ b/src/Zio/FileSystemEntry.cs
@@ -121,7 +121,7 @@ public override string ToString()
     }
 
     /// <inheritdoc />
-    public bool Equals(FileSystemEntry other)
+    public bool Equals(FileSystemEntry? other)
     {
         if (other is null) return false;
         if (ReferenceEquals(this, other)) return true;
diff --git a/src/Zio/FileSystems/MemoryFileSystem.cs b/src/Zio/FileSystems/MemoryFileSystem.cs
index 563f9a4..c96c2e8 100644
--- a/src/Zio/FileSystems/MemoryFileSystem.cs
+++ b/src/Zio/FileSystems/MemoryFileSystem.cs
@@ -796,7 +796,7 @@ protected override IEnumerable<UPath> EnumeratePathsImpl(UPath path, string sear
                         // and the time we are going to actually visit it, it might have been
                         // removed in the meantime, so we make sure here that we have a folder
                         // and we don't throw an error if it is not
-                        if (!(result.Node is DirectoryNode))
+                        if (result.Node is not DirectoryNode)
                         {
                             continue;
                         }
@@ -885,7 +885,7 @@ protected override IEnumerable<FileSystemItem> EnumerateItemsImpl(UPath path, Se
                         // and the time we are going to actually visit it, it might have been
                         // removed in the meantime, so we make sure here that we have a folder
                         // and we don't throw an error if it is not
-                        if (!(result.Node is DirectoryNode))
+                        if (result.Node is not DirectoryNode)
                         {
                             continue;
                         }
@@ -1106,8 +1106,7 @@ void AssertNoDestination(FileSystemNode node)
         }
     }
 
-    
-    private void ValidateDirectory([NotNull] FileSystemNode? node, UPath srcPath)
+    private static void ValidateDirectory([NotNull] FileSystemNode? node, UPath srcPath)
     {
         if (node is FileNode)
         {
@@ -1120,7 +1119,7 @@ private void ValidateDirectory([NotNull] FileSystemNode? node, UPath srcPath)
         }
     }
 
-    private void ValidateFile([NotNull] FileSystemNode? node, UPath srcPath)
+    private static void ValidateFile([NotNull] FileSystemNode? node, UPath srcPath)
     {
         if (node is null)
         {
diff --git a/src/Zio/FileSystems/MountFileSystem.cs b/src/Zio/FileSystems/MountFileSystem.cs
index 67924c0..2a666aa 100644
--- a/src/Zio/FileSystems/MountFileSystem.cs
+++ b/src/Zio/FileSystems/MountFileSystem.cs
@@ -33,7 +33,7 @@ public MountFileSystem(bool owned = true) : this(null, owned)
     /// Initializes a new instance of the <see cref="MountFileSystem"/> class with a default backup filesystem.
     /// </summary>
     /// <param name="defaultBackupFileSystem">The default backup file system.</param>
-    /// <param name="owned">True if <paramref name="defaultBackupFileSystem"/> and mounted filesytems should be disposed when this instance is disposed.</param>
+    /// <param name="owned">True if <paramref name="defaultBackupFileSystem"/> and mounted filesystems should be disposed when this instance is disposed.</param>
     public MountFileSystem(IFileSystem? defaultBackupFileSystem, bool owned = true) : base(defaultBackupFileSystem, owned)
     {
         _mounts = new SortedList<UPath, IFileSystem>(new UPathLengthComparer());
@@ -144,7 +144,7 @@ public IFileSystem Unmount(UPath name)
     {
         ValidateMountName(name);
 
-        IFileSystem mountFileSystem;
+        IFileSystem? mountFileSystem;
 
         if (!_mounts.TryGetValue(name, out mountFileSystem))
         {
@@ -1011,7 +1011,7 @@ private static UPath CombinePrefix(UPath prefix, UPath remaining)
             : prefix / remaining.ToRelative();
     }
 
-    private void ValidateMountName(UPath name)
+    private static void ValidateMountName(UPath name)
     {
         name.AssertAbsolute(nameof(name));
         if (name == UPath.Root)
diff --git a/src/Zio/UPath.cs b/src/Zio/UPath.cs
index 0d9a5d7..f80d9a5 100644
--- a/src/Zio/UPath.cs
+++ b/src/Zio/UPath.cs
@@ -194,7 +194,7 @@ public bool Equals(UPath other)
     }
 
     /// <inheritdoc />
-    public override bool Equals(object obj)
+    public override bool Equals(object? obj)
     {
         return obj is UPath path && Equals(path);
     }