From c055bc6c7853efbc984418dd70469653872dbce1 Mon Sep 17 00:00:00 2001
From: Joseph Doherty <dohejw01@gmail.com>
Date: Mon, 19 Jan 2026 17:33:39 -0500
Subject: [PATCH] feat(configmanager): add IFileSystem abstraction

Add file system abstraction to enable testability for file operations.
- IFileSystem interface with common file operations
- FileSystem implementation wrapping System.IO
- Unit tests for FileExists functionality
---
 .../Services/FileSystem.cs                    | 40 +++++++++++++++++++
 .../Services/IFileSystem.cs                   | 19 +++++++++
 .../Services/FileSystemTests.cs               | 40 +++++++++++++++++++
 3 files changed, 99 insertions(+)
 create mode 100644 NEW/src/Utils/JdeScoping.ConfigManager/Services/FileSystem.cs
 create mode 100644 NEW/src/Utils/JdeScoping.ConfigManager/Services/IFileSystem.cs
 create mode 100644 NEW/tests/JdeScoping.ConfigManager.Tests/Services/FileSystemTests.cs

diff --git a/NEW/src/Utils/JdeScoping.ConfigManager/Services/FileSystem.cs b/NEW/src/Utils/JdeScoping.ConfigManager/Services/FileSystem.cs
new file mode 100644
index 0000000..00f5de1
--- /dev/null
+++ b/NEW/src/Utils/JdeScoping.ConfigManager/Services/FileSystem.cs
@@ -0,0 +1,40 @@
+namespace JdeScoping.ConfigManager.Services;
+
+/// <summary>
+/// Real file system implementation.
+/// </summary>
+public class FileSystem : IFileSystem
+{
+    public bool FileExists(string path) => File.Exists(path);
+
+    public bool DirectoryExists(string path) => Directory.Exists(path);
+
+    public async Task<string> ReadAllTextAsync(string path, CancellationToken ct = default)
+        => await File.ReadAllTextAsync(path, ct);
+
+    public async Task WriteAllTextAsync(string path, string content, CancellationToken ct = default)
+        => await File.WriteAllTextAsync(path, content, ct);
+
+    public Task<string[]> GetFilesAsync(string directory, string pattern, CancellationToken ct = default)
+        => Task.FromResult(Directory.GetFiles(directory, pattern));
+
+    public async Task CopyFileAsync(string source, string destination, CancellationToken ct = default)
+    {
+        var content = await File.ReadAllBytesAsync(source, ct);
+        await File.WriteAllBytesAsync(destination, content, ct);
+    }
+
+    public Task DeleteFileAsync(string path, CancellationToken ct = default)
+    {
+        File.Delete(path);
+        return Task.CompletedTask;
+    }
+
+    public string GetDirectoryName(string path) => Path.GetDirectoryName(path) ?? string.Empty;
+
+    public string GetFileName(string path) => Path.GetFileName(path);
+
+    public string GetFileNameWithoutExtension(string path) => Path.GetFileNameWithoutExtension(path);
+
+    public string Combine(params string[] paths) => Path.Combine(paths);
+}
diff --git a/NEW/src/Utils/JdeScoping.ConfigManager/Services/IFileSystem.cs b/NEW/src/Utils/JdeScoping.ConfigManager/Services/IFileSystem.cs
new file mode 100644
index 0000000..b5d265f
--- /dev/null
+++ b/NEW/src/Utils/JdeScoping.ConfigManager/Services/IFileSystem.cs
@@ -0,0 +1,19 @@
+namespace JdeScoping.ConfigManager.Services;
+
+/// <summary>
+/// Abstraction for file system operations to enable testing.
+/// </summary>
+public interface IFileSystem
+{
+    bool FileExists(string path);
+    bool DirectoryExists(string path);
+    Task<string> ReadAllTextAsync(string path, CancellationToken ct = default);
+    Task WriteAllTextAsync(string path, string content, CancellationToken ct = default);
+    Task<string[]> GetFilesAsync(string directory, string pattern, CancellationToken ct = default);
+    Task CopyFileAsync(string source, string destination, CancellationToken ct = default);
+    Task DeleteFileAsync(string path, CancellationToken ct = default);
+    string GetDirectoryName(string path);
+    string GetFileName(string path);
+    string GetFileNameWithoutExtension(string path);
+    string Combine(params string[] paths);
+}
diff --git a/NEW/tests/JdeScoping.ConfigManager.Tests/Services/FileSystemTests.cs b/NEW/tests/JdeScoping.ConfigManager.Tests/Services/FileSystemTests.cs
new file mode 100644
index 0000000..64a33ea
--- /dev/null
+++ b/NEW/tests/JdeScoping.ConfigManager.Tests/Services/FileSystemTests.cs
@@ -0,0 +1,40 @@
+using JdeScoping.ConfigManager.Services;
+
+namespace JdeScoping.ConfigManager.Tests.Services;
+
+public class FileSystemTests
+{
+    [Fact]
+    public void FileExists_WithExistingFile_ReturnsTrue()
+    {
+        // Arrange
+        var sut = new FileSystem();
+        var tempFile = Path.GetTempFileName();
+
+        try
+        {
+            // Act
+            var result = sut.FileExists(tempFile);
+
+            // Assert
+            result.ShouldBeTrue();
+        }
+        finally
+        {
+            File.Delete(tempFile);
+        }
+    }
+
+    [Fact]
+    public void FileExists_WithNonExistingFile_ReturnsFalse()
+    {
+        // Arrange
+        var sut = new FileSystem();
+
+        // Act
+        var result = sut.FileExists("/nonexistent/path/file.txt");
+
+        // Assert
+        result.ShouldBeFalse();
+    }
+}