Implemented the "init(at: )" initialiser, the "pathString" computed property, and the "appendingPath(_: )" function for the URL+Extensions extension in the library target.

Sources/Library/Extensions/URL+Extensions.swift

@@ -0,0 +1,35 @@
+import Foundation
+
+extension URL {
+    
+    // MARK: Initialisers
+    
+    init(at filePath: String) {
+        if #available(macOS 13.0, *) {
+            self = URL(filePath: filePath)
+        } else {
+            self = URL(fileURLWithPath: filePath)
+        }
+    }
+    
+    // MARK: Computed
+    
+    var pathString: String {
+        if #available(macOS 13.0, *) {
+            path()
+        } else {
+            path
+        }
+    }
+    
+    // MARK: Functions
+    
+    func appendingPath(_ path: String) -> URL {
+        if #available(macOS 13.0, *) {
+            appending(path: path)
+        } else {
+            appendingPathComponent(path)
+        }
+    }
+    
+}

Sources/Library/Extensions/URL+Inits.swift

@@ -1,15 +0,0 @@
-import Foundation
-
-extension URL {
-    
-    // MARK: Initialisers
-    
-    init(at filePath: String) {
-        if #available(macOS 13.0, *) {
-            self = URL(filePath: filePath)
-        } else {
-            self = URL(fileURLWithPath: filePath)
-        }
-    }
-    
-}

Sources/Library/Services/FileService.swift

@@ -54,25 +54,9 @@ public struct FileService: FileServicing {
             throw FileServiceError.urlNotFileURL
         }
         
-        let filePath = getPath(for: url)
+        let filePath = url.pathString
         
         return fileManager.fileExists(atPath: filePath)
     }
     
 }
-
-// MARK: - Helpers
-
-private extension FileService {
-    
-    // MARK: Functions
-    
-    func getPath(for url: URL) -> String {
-        if #available(macOS 13.0, *) {
-            return url.path()
-        } else {
-            return url.path
-        }
-    }
-    
-}

Sources/Library/Tasks/CreateRootFolderTask.swift

@@ -27,12 +27,8 @@ public struct CreateRootFolderTask {
         } else {
             await fileService.currentFolder
         }
-        
-        let newFolder = if #available(macOS 13.0, *) {
-            rootFolder.appending(path: name)
-        } else {
-            rootFolder.appendingPathComponent(name)
-        }
+
+        let newFolder = rootFolder.appendingPath(name)
 
         try await fileService.createFolder(at: newFolder)
         

Tests/Library/Cases/Extensions/URL+ExtensionsTests.swift

@@ -0,0 +1,76 @@
+import Foundation
+import Testing
+
+@testable import ColibriLibrary
+
+struct URL_ExtensionsTests {
+    
+    // MARK: Initialisers tests
+
+    @Test(arguments: zip([String.someFilePath, .dotPath, .tildePath],
+                         [URL.someFile, .dotFile, .tildeFile]))
+    func initAt(
+        with filePath: String,
+        expects url: URL
+    ) async throws {
+        // GIVEN
+        // WHEN
+        let result = URL(at: filePath)
+
+        // THEN
+        #expect(result == url)
+        #expect(result.isFileURL == true)
+    }
+
+    // MARK: Computed tests
+    
+    @Test(arguments: zip([URL.someFile, .dotFile, .tildeFile, .someURL],
+                         [String.someFilePath, .dotPath, .tildePath, .empty]))
+    func pathString(
+        with url: URL,
+        expects path: String
+    ) async throws {
+        // GIVEN
+        // WHEN
+        let result = url.pathString
+        
+        // THEN
+        #expect(result == path)
+    }
+    
+    // MARK: Functions tests
+    
+    @Test(arguments: zip([URL.dotFile, .tildeFile, .someFile],
+                       [".\(String.someFilePath)", "~\(String.someFilePath)", "\(String.someFilePath)\(String.someFilePath)"]))
+    func appendingPath(
+        with url: URL,
+        expects path: String
+    ) async throws {
+        // GIVEN
+        // WHEN
+        let result = url.appendingPath(.someFilePath)
+        
+        // THEN
+        #expect(result.pathString == path)
+        #expect(result.isFileURL == true)
+    }
+
+}
+
+// MARK: - String+Constants
+
+private extension String {
+    static let dotPath = "."
+    static let empty = ""
+    static let tildePath = "~"
+    static let someFilePath = "/some/file/path"
+}
+
+// MARK: - URL+Constants
+
+private extension URL {
+    static let dotFile = URL(at: .dotPath)
+    static let someFile = URL(at: .someFilePath)
+    static let someURL = URL(string: "https://some.url.path")!
+    static let tildeFile = URL(at: .tildePath)
+}