Implemented the CreatedRootFolderTask task in the Library target.

Sources/Library/Tasks/CreateRootFolderTask.swift

@@ -0,0 +1,38 @@
+import Foundation
+
+public struct CreateRootFolderTask {
+    
+    // MARK: Properties
+    
+    private let fileService: FileServicing
+    
+    // MARK: Initialisers
+    
+    public init(fileService: FileServicing) {
+        self.fileService = fileService
+    }
+    
+    // MARK: Functions
+    
+    public func callAsFunction(
+        name: String,
+        at location: URL? = nil
+    ) async throws -> URL {
+        let rootFolder = if let location {
+            location
+        } else {
+            await fileService.currentFolder
+        }
+        
+        let newFolder = if #available(macOS 13.0, *) {
+            rootFolder.appending(path: name)
+        } else {
+            rootFolder.appendingPathComponent(name)
+        }
+
+        try await fileService.createFolder(at: newFolder)
+        
+        return newFolder
+    }
+    
+}

Tests/Library/Cases/Services/FileServiceTests.swift

@@ -1,8 +1,7 @@
+import ColibriLibrary
 import Foundation
 import Testing
 
-@testable import ColibriLibrary
-
 struct FileServiceTests {
     
     // MARK: Properties
@@ -153,14 +152,3 @@ struct FileServiceTests {
     }
 
 }
-
-// MARK: - URL+Constants
-
-private extension URL {
-    static let someCurrentFolder = URL(at: "/some/current/folder")
-    static let someExistingFolder = URL(at: "/some/existing/folder")
-    static let someExistingFile = URL(at: "/some/existing/file")
-    static let someNewFolder = URL(at: "/some/new/folder")
-    static let someNewFile = URL(at: "/some/new/file")
-    static let someRandomURL = URL(string: "some.random.url")!
-}

Tests/Library/Cases/Tasks/CreateRootFolderTaskTests.swift

@@ -0,0 +1,64 @@
+import ColibriLibrary
+import Foundation
+import Testing
+
+struct CreateRootFolderTaskTests {
+
+    // MARK: Functions tests
+    
+    @Test(arguments: [String.someProjectName], [URL.someCurrentProjectFolder, .someNewProjectFolder])
+    func task(
+        name: String,
+        expects folder: URL
+    ) async throws {
+        // GIVEN
+        let fileService = FileServiceMock(
+            currentFolder: .someCurrentFolder,
+            action: .createFolder(folder)
+        )
+
+        let task = CreateRootFolderTask(fileService: fileService)
+
+        // WHEN
+        let result = try await task(name: name,
+                                    at: folder == .someNewProjectFolder ? .someNewFolder : nil)
+        
+        // THEN
+        #expect(result == folder)
+        #expect(result.isFileURL == true)
+    }
+    
+    @Test(arguments: [String.someProjectName], [FileServiceError.urlAlreadyExists])
+    func task(
+        name: String,
+        throws error: FileServiceError
+    ) async throws {
+        // GIVEN
+        let fileService = FileServiceMock(
+            currentFolder: .someCurrentFolder,
+            action: .error(error)
+        )
+        
+        let task = CreateRootFolderTask(fileService: fileService)
+        
+        // WHEN
+        // THEN
+        await #expect(throws: error) {
+            try await task(name: name)
+        }
+    }
+
+}
+
+// MARK: - String+Constants
+
+private extension String {
+    static let someProjectName = "SomeProjectName"
+}
+
+// MARK: - URL+Constants
+
+private extension URL {
+    static let someCurrentProjectFolder = URL.someCurrentFolder.appending(component: String.someProjectName)
+    static let someNewProjectFolder = URL.someNewFolder.appending(component: String.someProjectName)
+}

Tests/Library/Helpers/Extensions/URL+Samples.swift

@@ -0,0 +1,16 @@
+import Foundation
+
+@testable import ColibriLibrary
+
+extension URL {
+    
+    // MARK: Constants
+    
+    static let someCurrentFolder = URL(at: "/some/current/folder")
+    static let someExistingFolder = URL(at: "/some/existing/folder")
+    static let someExistingFile = URL(at: "/some/existing/file")
+    static let someNewFolder = URL(at: "/some/new/folder")
+    static let someNewFile = URL(at: "/some/new/file")
+    static let someRandomURL = URL(string: "some.random.url")!
+    
+}

Tests/Library/Helpers/Spies/FileServiceSpy.swift

@@ -39,9 +39,3 @@ extension FileServiceSpy: FileServicing {
     }
     
 }
-
-// MARK: - URL+Constants
-
-private extension URL {
-    static let someCurrentFolder = URL(at: "some/current/folder")
-}