test(auth): increase code coverage

.swiftpm/xcode/xcshareddata/xcschemes/Auth.xcscheme

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <Scheme
    LastUpgradeVersion = "1530"
-   version = "1.7">
+   version = "1.3">
    <BuildAction
       parallelizeBuildables = "YES"
       buildImplicitDependencies = "YES"
@@ -27,8 +27,29 @@
       buildConfiguration = "Debug"
       selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
       selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
-      shouldUseLaunchSchemeArgsEnv = "YES">
+      shouldUseLaunchSchemeArgsEnv = "YES"
+      codeCoverageEnabled = "YES"
+      onlyGenerateCoverageForSpecifiedTargets = "YES">
+      <CodeCoverageTargets>
+         <BuildableReference
+            BuildableIdentifier = "primary"
+            BlueprintIdentifier = "Auth"
+            BuildableName = "Auth"
+            BlueprintName = "Auth"
+            ReferencedContainer = "container:">
+         </BuildableReference>
+      </CodeCoverageTargets>
       <Testables>
+         <TestableReference
+            skipped = "NO">
+            <BuildableReference
+               BuildableIdentifier = "primary"
+               BlueprintIdentifier = "AuthTests"
+               BuildableName = "AuthTests"
+               BlueprintName = "AuthTests"
+               ReferencedContainer = "container:">
+            </BuildableReference>
+         </TestableReference>
       </Testables>
    </TestAction>
    <LaunchAction

Sources/Auth/AuthClient.swift

@@ -29,6 +29,7 @@
   private var eventEmitter: AuthStateChangeEventEmitter { Dependencies[clientID].eventEmitter }
   private var logger: (any SupabaseLogger)? { Dependencies[clientID].configuration.logger }
   private var sessionStorage: SessionStorage { Dependencies[clientID].sessionStorage }
+  private var pkce: PKCE { Dependencies[clientID].pkce }
 
   /// Returns the session, refreshing it if necessary.
   ///
@@ -1310,10 +1311,10 @@
       return (nil, nil)
     }
 
-    let codeVerifier = PKCE.generateCodeVerifier()
+    let codeVerifier = pkce.generateCodeVerifier()
     codeVerifierStorage.set(codeVerifier)
 
-    let codeChallenge = PKCE.generateCodeChallenge(from: codeVerifier)
+    let codeChallenge = pkce.generateCodeChallenge(codeVerifier)
     let codeChallengeMethod = codeVerifier == codeChallenge ? "plain" : "s256"
 
     return (codeChallenge, codeChallengeMethod)
@@ -1403,7 +1404,7 @@
   final class DefaultPresentationContextProvider: NSObject,
     ASWebAuthenticationPresentationContextProviding
   {
     func presentationAnchor(for _: ASWebAuthenticationSession) -> ASPresentationAnchor {
       ASPresentationAnchor()
     }
   }

Sources/Auth/AuthMFA.swift

@@ -54,6 +54,7 @@ public struct AuthMFA: Sendable {
   ///
   /// - Parameter params: The parameters for verifying the MFA factor.
   /// - Returns: An authentication response after verifying the factor.
+  @discardableResult
   public func verify(params: MFAVerifyParams) async throws -> AuthMFAVerifyResponse {
     let response: AuthMFAVerifyResponse = try await api.authorizedExecute(
       HTTPRequest(

Sources/Auth/Internal/Dependencies.swift

@@ -14,6 +14,7 @@ struct Dependencies: Sendable {
   var date: @Sendable () -> Date = { Date() }
 
   var urlOpener: URLOpener = .live
+  var pkce: PKCE = .live
 
   var encoder: JSONEncoder { configuration.encoder }
   var decoder: JSONDecoder { configuration.decoder }

Sources/Auth/Internal/PKCE.swift

@@ -1,22 +1,28 @@
 import Crypto
 import Foundation
 
-enum PKCE {
-  static func generateCodeVerifier() -> String {
-    let buffer = [UInt8].random(count: 64)
-    return Data(buffer).pkceBase64EncodedString()
-  }
+struct PKCE {
+  var generateCodeVerifier: @Sendable () -> String
+  var generateCodeChallenge: @Sendable (_ codeVerifier: String) -> String
+}
 
-  static func generateCodeChallenge(from string: String) -> String {
-    guard let data = string.data(using: .utf8) else {
-      preconditionFailure("provided string should be utf8 encoded.")
-    }
+extension PKCE {
+  static let live = PKCE(
+    generateCodeVerifier: {
+      let buffer = [UInt8].random(count: 64)
+      return Data(buffer).pkceBase64EncodedString()
+    },
+    generateCodeChallenge: { codeVerifier in
+      guard let data = codeVerifier.data(using: .utf8) else {
+        preconditionFailure("provided string should be utf8 encoded.")
+      }
 
-    var hasher = SHA256()
-    hasher.update(data: data)
-    let hashed = hasher.finalize()
-    return Data(hashed).pkceBase64EncodedString()
-  }
+      var hasher = SHA256()
+      hasher.update(data: data)
+      let hashed = hasher.finalize()
+      return Data(hashed).pkceBase64EncodedString()
+    }
+  )
 }
 
 extension Data {

Tests/AuthTests/AuthClientMultipleInstancesTests.swift

@@ -5,10 +5,11 @@
 //  Created by Guilherme Souza on 05/07/24.
 //
 
-@testable import Auth
 import TestHelpers
 import XCTest
 
+@testable import Auth
+
 final class AuthClientMultipleInstancesTests: XCTestCase {
   func testMultipleAuthClientInstances() {
     let url = URL(string: "http://localhost:54321/auth")!