Update WealthsimpleDownloader to Swift Testing and refactor to inject dependencies

Sources/WealthsimpleDownloader/DownloaderDependencies.swift

@@ -0,0 +1,49 @@
+import Foundation
+#if canImport(FoundationNetworking)
+@preconcurrency import FoundationNetworking
+#endif
+
+protocol HTTPClient {
+    func send(
+        _ request: URLRequest,
+        body: Data?,
+        completion: @escaping (Data?, URLResponse?, Error?) -> Void
+    )
+}
+
+private final class HTTPCompletionBox: @unchecked Sendable {
+    let completion: (Data?, URLResponse?, Error?) -> Void
+
+    init(_ completion: @escaping (Data?, URLResponse?, Error?) -> Void) {
+        self.completion = completion
+    }
+}
+
+struct URLSessionHTTPClient: HTTPClient {
+    let session: URLSession
+
+    init(session: URLSession = .shared) {
+        self.session = session
+    }
+
+    func send(
+        _ request: URLRequest,
+        body: Data?,
+        completion: @escaping (Data?, URLResponse?, Error?) -> Void
+    ) {
+        var request = request
+        request.httpBody = body
+        let completionBox = HTTPCompletionBox(completion)
+        session.dataTask(with: request) { data, response, error in
+            completionBox.completion(data, response, error)
+        }
+        .resume()
+    }
+}
+
+struct DownloaderDependencies {
+    static let live = Self(httpClient: URLSessionHTTPClient(), configuration: URLConfiguration())
+
+    let httpClient: HTTPClient
+    let configuration: URLConfiguration
+}

Sources/WealthsimpleDownloader/Token.swift

@@ -33,25 +33,27 @@ struct Token {
     private static let credentialStorageKeyAccessToken = "accessToken"
     private static let credentialStorageKeyRefreshToken = "refreshToken"
     private static let credentialStorageKeyExpiry = "expiry"
+    private static let tokenPath = "oauth/v2/token"
+    private static let tokenValidationPath = "oauth/v2/token/info"
 
-    private static var url: URL { URLConfiguration.shared.urlObject(for: "oauth/v2/token")! }
-    private static var testUrl: URL { URLConfiguration.shared.urlObject(for: "oauth/v2/token/info")! }
     private static var clientId = "4da53ac2b03225bed1550eba8e4611e086c7b905a3855e6ed12ea08c246758fa" // From the website
     private static var scope = "read" // the clientId supports some write scopes, but as this library only reads we limit it for safety
 
     private let accessToken: String
     private let refreshToken: String
     private let expiry: Date
     private let credentialStorage: CredentialStorage
+    private let dependencies: DownloaderDependencies
 
-    private init(accessToken: String, refreshToken: String, expiry: Date, credentialStorage: CredentialStorage) {
+    private init(accessToken: String, refreshToken: String, expiry: Date, credentialStorage: CredentialStorage, dependencies: DownloaderDependencies) {
         self.accessToken = accessToken
         self.refreshToken = refreshToken
         self.expiry = expiry
         self.credentialStorage = credentialStorage
+        self.dependencies = dependencies
     }
 
-    private init(json: [String: Any], credentialStorage: CredentialStorage) throws {
+    private init(json: [String: Any], credentialStorage: CredentialStorage, dependencies: DownloaderDependencies) throws {
         guard let accessToken = json["access_token"] as? String,
               let expiresIn = json["expires_in"] as? Int,
               let createdAt = json["created_at"] as? Int,
@@ -63,10 +65,18 @@ struct Token {
         let expiresAt = createdAt + expiresIn
         self.expiry = Date(timeIntervalSince1970: TimeInterval(expiresAt))
         self.credentialStorage = credentialStorage
+        self.dependencies = dependencies
     }
 
-    static func getToken(username: String, password: String, otp: String, credentialStorage: CredentialStorage, completion: @escaping (Result<Self, TokenError>) -> Void) {
-        var request = URLRequest(url: url)
+    static func getToken(
+        username: String,
+        password: String,
+        otp: String,
+        credentialStorage: CredentialStorage,
+        dependencies: DownloaderDependencies = .live,
+        completion: @escaping (Result<Self, TokenError>) -> Void
+    ) {
+        var request = URLRequest(url: dependencies.configuration.urlObject(for: Self.tokenPath)!)
         request.setValue(otp, forHTTPHeaderField: "x-wealthsimple-otp")
         let json = [
             "grant_type": "password",
@@ -75,18 +85,24 @@ struct Token {
             "scope": scope,
             "client_id": clientId
         ]
-        sendTokenRequest(parameters: json, request: request, credentialStorage: credentialStorage, completion: completion)
+        sendTokenRequest(parameters: json, request: request, credentialStorage: credentialStorage, dependencies: dependencies, completion: completion)
     }
 
-    static func getToken(from credentialStorage: CredentialStorage, completion: @escaping (Self?) -> Void) {
+    static func getToken(from credentialStorage: CredentialStorage, dependencies: DownloaderDependencies = .live, completion: @escaping (Self?) -> Void) {
         guard let accessToken = credentialStorage.read(credentialStorageKeyAccessToken),
               let refreshToken = credentialStorage.read(credentialStorageKeyRefreshToken),
               let expiryString = credentialStorage.read(credentialStorageKeyExpiry),
               let expiryDouble = Double(expiryString) else {
             completion(nil)
             return
         }
-        let token = Self(accessToken: accessToken, refreshToken: refreshToken, expiry: Date(timeIntervalSince1970: expiryDouble), credentialStorage: credentialStorage)
+        let token = Self(
+            accessToken: accessToken,
+            refreshToken: refreshToken,
+            expiry: Date(timeIntervalSince1970: expiryDouble),
+            credentialStorage: credentialStorage,
+            dependencies: dependencies
+        )
         token.refreshIfNeeded {
             switch $0 {
             case .failure:
@@ -107,27 +123,28 @@ struct Token {
         parameters json: [String: String],
         request urlRequest: URLRequest,
         credentialStorage: CredentialStorage,
+        dependencies: DownloaderDependencies,
         completion: @escaping (Result<Self, TokenError>) -> Void
     ) {
         var request = urlRequest
-        let session = URLSession.shared
         request.httpMethod = "POST"
         request.setValue("application/json", forHTTPHeaderField: "Content-Type")
         guard let jsonData = try? JSONSerialization.data(withJSONObject: json, options: []) else {
             completion(.failure(TokenError.invalidParameters(parameters: json)))
             return
         }
-        let task = session.uploadTask(with: request, from: jsonData) { data, response, error in
-            handleTokenResponse(data: data, response: response, error: error, credentialStorage: credentialStorage, completion: completion)
+        dependencies.httpClient.send(request, body: jsonData) { data, response, error in
+            handleTokenResponse(data: data, response: response, error: error, credentialStorage: credentialStorage, dependencies: dependencies, completion: completion)
         }
-        task.resume()
     }
 
+    // swiftlint:disable:next function_parameter_count
     private static func handleTokenResponse(
         data: Data?,
         response: URLResponse?,
         error: Error?,
         credentialStorage: CredentialStorage,
+        dependencies: DownloaderDependencies,
         completion: (Result<Self, TokenError>) -> Void
     ) {
         guard let data else {
@@ -146,15 +163,15 @@ struct Token {
             completion(.failure(TokenError.httpError(error: "Status code \(httpResponse.statusCode)")))
             return
         }
-        completion(parse(data: data, credentialStorage: credentialStorage))
+        completion(parse(data: data, credentialStorage: credentialStorage, dependencies: dependencies))
     }
 
-    private static func parse(data: Data, credentialStorage: CredentialStorage) -> Result<Self, TokenError> {
+    private static func parse(data: Data, credentialStorage: CredentialStorage, dependencies: DownloaderDependencies) -> Result<Self, TokenError> {
         guard let json = try? JSONSerialization.jsonObject(with: data, options: []) as? [String: Any] else {
             return .failure(TokenError.invalidJsonType(json: data))
         }
         do {
-            let token = try Self(json: json, credentialStorage: credentialStorage)
+            let token = try Self(json: json, credentialStorage: credentialStorage, dependencies: dependencies)
             token.saveToken()
             return .success(token)
         } catch {
@@ -163,11 +180,10 @@ struct Token {
     }
 
     private func testIfValid(completion: @escaping (Bool) -> Void) {
-        var request = URLRequest(url: Self.testUrl)
-        let session = URLSession.shared
+        var request = URLRequest(url: dependencies.configuration.urlObject(for: Self.tokenValidationPath)!)
         request.setValue("application/json", forHTTPHeaderField: "Content-Type")
         authenticateRequest(request) { request in
-            let task = session.dataTask(with: request) { _, response, error in
+            dependencies.httpClient.send(request, body: nil) { _, response, error in
                 guard error == nil else {
                     completion(false)
                     return
@@ -178,7 +194,6 @@ struct Token {
                 }
                 completion(httpResponse.statusCode == 200)
             }
-            task.resume()
         }
     }
 
@@ -201,13 +216,13 @@ struct Token {
     }
 
     private func refresh(completion: @escaping (Result<Self, TokenError>) -> Void) {
-        let request = URLRequest(url: Self.url)
+        let request = URLRequest(url: dependencies.configuration.urlObject(for: Self.tokenPath)!)
         let json = [
             "grant_type": "refresh_token",
             "refresh_token": refreshToken,
             "client_id": Self.clientId
         ]
-        Self.sendTokenRequest(parameters: json, request: request, credentialStorage: credentialStorage, completion: completion)
+        Self.sendTokenRequest(parameters: json, request: request, credentialStorage: credentialStorage, dependencies: dependencies, completion: completion)
     }
 
     private func saveToken() {

Sources/WealthsimpleDownloader/URLConfiguration.swift

@@ -10,19 +10,16 @@ import Foundation
 import FoundationNetworking
 #endif
 
-/// Singleton class that manages the base URL configuration for all Wealthsimple API endpoints
+/// Configures the REST and GraphQL endpoints used by Wealthsimple requests.
 final class URLConfiguration {
 
     private static let defaultBaseURL = "https://api.production.wealthsimple.com/v1/"
     private static let defaultGraphQLURL = "https://my.wealthsimple.com/graphql"
 
-    /// Shared singleton instance
-    static let shared = URLConfiguration()
-
     /// Base URL for all Wealthsimple API endpoints
-    private var baseURL: String = URLConfiguration.defaultBaseURL
+    private let baseURL: String
     /// GraphQL URL for Wealthsimple
-    private var graphQLURL: String = URLConfiguration.defaultGraphQLURL
+    private let graphQLURL: String
 
     /// Get the current base URL
     var base: String {
@@ -34,21 +31,13 @@ final class URLConfiguration {
         graphQLURL
     }
 
-    /// Private initializer to enforce singleton pattern
-    private init() {
-        // Singleton initialization
-    }
-
-    /// Set a new base URL (internal access for testing)
-    /// - Parameter url: The new base URL to use
-    func setBaseURL(_ url: String) {
-        baseURL = url
-    }
-
-    /// Set a new graphQL URL (internal access for testing)
-    /// - Parameter url: The new base URL to use
-    func setGraphQLURL(_ url: String) {
-        graphQLURL = url
+    /// Creates a configuration for the provided REST and GraphQL endpoints.
+    init(
+        baseURL: String = URLConfiguration.defaultBaseURL,
+        graphQLURL: String = URLConfiguration.defaultGraphQLURL
+    ) {
+        self.baseURL = baseURL
+        self.graphQLURL = graphQLURL
     }
 
     /// Create a full URL by appending a path to the base URL
@@ -85,9 +74,4 @@ final class URLConfiguration {
         return request
     }
 
-    func reset() {
-        baseURL = Self.defaultBaseURL
-        graphQLURL = Self.defaultGraphQLURL
-    }
-
 }

Sources/WealthsimpleDownloader/WealthsimpleAPI.swift

@@ -34,6 +34,7 @@ public final class WealthsimpleAPI {
 
     private let authenticationCallback: AuthenticationCallback
     private let credentialStorage: CredentialStorage
+    private let dependencies: DownloaderDependencies
     private var token: Token?
 
     /// Creates the Downloader instance
@@ -45,9 +46,14 @@ public final class WealthsimpleAPI {
     ///     Needs to return username, password, and one time password. Might be called during any call.
     ///   - credentialStorage: A CredentialStore to save API tokens to. Implementation can be empty,
     ///     in this case the authenticationCallback will be called every time and not only when the refresh token expired
-    public init(authenticationCallback: @escaping AuthenticationCallback, credentialStorage: CredentialStorage) {
+    public convenience init(authenticationCallback: @escaping AuthenticationCallback, credentialStorage: CredentialStorage) {
+        self.init(authenticationCallback: authenticationCallback, credentialStorage: credentialStorage, dependencies: .live)
+    }
+
+    init(authenticationCallback: @escaping AuthenticationCallback, credentialStorage: CredentialStorage, dependencies: DownloaderDependencies) {
         self.authenticationCallback = authenticationCallback
         self.credentialStorage = credentialStorage
+        self.dependencies = dependencies
     }
 
     /// Authneticates against the API. Call before calling any other method.
@@ -65,7 +71,7 @@ public final class WealthsimpleAPI {
             }
             return
         }
-        Token.getToken(from: credentialStorage) {
+        Token.getToken(from: credentialStorage, dependencies: dependencies) {
             if let token = $0 {
                 self.token = token
                 completion(nil)
@@ -84,7 +90,7 @@ public final class WealthsimpleAPI {
             completion(.failure(.tokenError(.noToken)))
             return
         }
-        WealthsimpleAccount.getAccounts(token: token) {
+        WealthsimpleAccount.getAccounts(token: token, dependencies: dependencies) {
             completion($0)
         }
     }
@@ -99,7 +105,7 @@ public final class WealthsimpleAPI {
             completion(.failure(.tokenError(.noToken)))
             return
         }
-        WealthsimplePosition.getPositions(token: token, account: account, date: date) {
+        WealthsimplePosition.getPositions(token: token, account: account, date: date, dependencies: dependencies) {
             completion($0)
         }
     }
@@ -114,14 +120,14 @@ public final class WealthsimpleAPI {
             completion(.failure(.tokenError(.noToken)))
             return
         }
-        WealthsimpleTransaction.getTransactions(token: token, account: account, startDate: startDate) {
+        WealthsimpleTransaction.getTransactions(token: token, account: account, startDate: startDate, dependencies: dependencies) {
             completion($0)
         }
     }
 
     private func getNewToken(completion: @escaping (Error?) -> Void) {
         authenticationCallback { username, password, otp in
-            Token.getToken(username: username, password: password, otp: otp, credentialStorage: self.credentialStorage) {
+            Token.getToken(username: username, password: password, otp: otp, credentialStorage: self.credentialStorage, dependencies: self.dependencies) {
                 switch $0 {
                 case let .failure(error):
                     completion(error)

Sources/WealthsimpleDownloader/WealthsimpleAccount.swift

@@ -70,7 +70,7 @@ public protocol Account {
 
 struct WealthsimpleAccount: Account {
 
-    private static var url: URL { URLConfiguration.shared.urlObject(for: "accounts")! }
+    private static let path = "accounts"
 
     let accountType: AccountType
     let currency: String
@@ -94,15 +94,13 @@ struct WealthsimpleAccount: Account {
         self.number = number
     }
 
-    static func getAccounts(token: Token, completion: @escaping (Result<[Account], AccountError>) -> Void) {
-        var request = URLRequest(url: url)
-        let session = URLSession.shared
+    static func getAccounts(token: Token, dependencies: DownloaderDependencies = .live, completion: @escaping (Result<[Account], AccountError>) -> Void) {
+        var request = URLRequest(url: dependencies.configuration.urlObject(for: Self.path)!)
         request.setValue("application/json", forHTTPHeaderField: "Content-Type")
         token.authenticateRequest(request) { request in
-            let task = session.dataTask(with: request) { data, response, error in
+            dependencies.httpClient.send(request, body: nil) { data, response, error in
                 handleResponse(data: data, response: response, error: error, completion: completion)
             }
-            task.resume()
         }
     }