Implemented the ArchiveController controller in the library target.

Library/Sources/Internal/Controllers/ArchiveController.swift

@@ -1,11 +1,33 @@
 import Hummingbird
 
+/// A controller that handles
 struct ArchiveController<Context: RequestContext> {
     
+    // MARK: Properties
+    
+    private let fileService: any FileServicing
+    private let folderArchives: String
+
+    // MARK: Initialisers
+    
+    /// Initialises this controller.
+    /// - Parameters:
+    ///   - folderArchives: <#folderArchives description#>
+    ///   - fileService: <#fileService description#>
+    init(
+        _ folderArchives: String,
+        fileService: any FileServicing = FileService()
+    ) {
+        self.folderArchives = folderArchives
+        self.fileService = fileService
+    }
+    
     // MARK: Functions
     
+    /// Registers the controller to a given router.
+    /// - Parameter router: A router to register this controller to.
     func register(to router: Router<Context>) {
-        router.get("archives", use: listAllArchives)
+        router.get(.archives, use: listAllArchives)
     }
     
 }
@@ -19,8 +41,25 @@ private extension ArchiveController {
     @Sendable func listAllArchives(
         _ request: Request,
         context: Context
-    ) async throws -> HTTPResponse.Status {
-        .ok
+    ) async throws -> ArchiveList {
+        let archives = try await fileService
+            .listItems(in: folderArchives)
+            .filter { $0.hasSuffix(.suffixArchive) }
+            .sorted { $0 < $1 }
+
+        return .init(archives)
     }
     
 }
+
+// MARK: - RouterPath+Constants
+
+private extension RouterPath {
+    static let archives: RouterPath = .init("archives")
+}
+
+// MARK: - String+Constants
+
+private extension String {
+    static let suffixArchive: String = ".doccarchive"
+}

Test/Sources/Cases/Internal/Controllers/ArchiveControllerTests.swift

@@ -0,0 +1,56 @@
+import Foundation
+import Hummingbird
+import HummingbirdTesting
+import Testing
+
+@testable import DoxyLibrary
+
+@Suite("ArchiveController", .tags(.controller))
+struct ArchiveControllerTests {
+    
+    // MARK: Properties
+    
+    private let decoder: JSONDecoder = .init()
+
+    @Test func xxx() async throws {
+        // GIVEN
+        let fileService = FileServiceMock(items: ["SomeArchive.doccarchive", "some-file.txt"])
+        let router = Router()
+        
+        ArchiveController("/path/to/archives/folder", fileService: fileService)
+            .register(to: router)
+
+        let app = Application(router: router)
+        
+        // WHEN
+        // THEN
+        try await app.test(.router) { client in
+            try await client.execute(uri: "/archives", method: .get) { response in
+                let archiveList = try decoder.decode(ArchiveList.self, from: response.body)
+                
+                #expect(response.status == .ok)
+                #expect(archiveList.archives == ["SomeArchive.doccarchive"])
+            }
+        }
+    }
+    
+    @Test func yyy() async throws {
+        // GIVEN
+        let fileService = FileServiceMock(error: .folderNotFound)
+        let router = Router()
+        
+        ArchiveController("/path/to/archives/folder", fileService: fileService)
+            .register(to: router)
+        
+        let app = Application(router: router)
+        
+        // WHEN
+        // THEN
+        try await app.test(.router) { client in
+            try await client.execute(uri: "/archives", method: .get) { response in
+                #expect(response.status == .ok)
+            }
+        }
+    }
+
+}

Test/Sources/Helpers/Extensions/Tag+Definitions.swift

@@ -5,6 +5,7 @@ extension Tag {
     // MARK: Constants
     
     @Tag static var builder: Tag
+    @Tag static var controller: Tag
     @Tag static var enumeration: Tag
     @Tag static var middleware: Tag
     @Tag static var provider: Tag

Test/Sources/Helpers/Mocks/FileServiceMock.swift

@@ -0,0 +1,36 @@
+@testable import DoxyLibrary
+
+struct FileServiceMock {
+    
+    // MARK: Properties
+    
+    private let error: FileServiceError?
+    private let items: [String]
+    
+    // MARK: Initialisers
+    
+    init(
+        items: [String] = [],
+        error: FileServiceError? = nil
+    ) {
+        self.error = error
+        self.items = items
+    }
+    
+}
+
+// MARK: - FileServicing
+
+extension FileServiceMock: FileServicing {
+    
+    // MARK: Functions
+    
+    func listItems(in folder: String) async throws(FileServiceError) -> [String] {
+        if let error {
+            throw error
+        }
+        
+        return items
+    }
+    
+}