Remove parameterless tokenExchange() method (#573)

* Remove parameterless `tokenExchange()` method

* Address review feedback

Auth0/Auth0Authentication.swift

@@ -270,22 +270,8 @@ struct Auth0Authentication: Authentication {
                        telemetry: self.telemetry)
     }
 
-    func tokenExchange() -> Request<Credentials, AuthenticationError> {
-        let payload: [String: Any] = [
-            "client_id": self.clientId
-        ]
-        let token = URL(string: "oauth/token", relativeTo: self.url)!
-        return Request(session: session,
-                       url: token,
-                       method: "POST",
-                       handle: codable,
-                       parameters: payload,
-                       logger: self.logger,
-                       telemetry: self.telemetry)
-    }
-
-    func tokenExchange(withCode code: String, codeVerifier: String, redirectURI: String) -> Request<Credentials, AuthenticationError> {
-        return self.tokenExchange().parameters([
+    func codeExchange(withCode code: String, codeVerifier: String, redirectURI: String) -> Request<Credentials, AuthenticationError> {
+        return self.token().parameters([
             "code": code,
             "code_verifier": codeVerifier,
             "redirect_uri": redirectURI,
@@ -340,6 +326,7 @@ struct Auth0Authentication: Authentication {
 // MARK: - Private Methods
 
 private extension Auth0Authentication {
+
     func login(username: String, otp: String, realm: String, audience: String?, scope: String) -> Request<Credentials, AuthenticationError> {
         let url = URL(string: "oauth/token", relativeTo: self.url)!
         var payload: [String: Any] = [
@@ -360,13 +347,28 @@ private extension Auth0Authentication {
                        telemetry: self.telemetry)
     }
 
+    func token() -> Request<Credentials, AuthenticationError> {
+        let payload: [String: Any] = [
+            "client_id": self.clientId
+        ]
+        let token = URL(string: "oauth/token", relativeTo: self.url)!
+        return Request(session: session,
+                       url: token,
+                       method: "POST",
+                       handle: codable,
+                       parameters: payload,
+                       logger: self.logger,
+                       telemetry: self.telemetry)
+    }
+
     func tokenExchange(subjectToken: String, subjectTokenType: String, scope: String, audience: String?, parameters: [String: Any]?) -> Request<Credentials, AuthenticationError> {
         var parameters: [String: Any] = parameters ?? [:]
         parameters["grant_type"] = "urn:ietf:params:oauth:grant-type:token-exchange"
         parameters["subject_token"] = subjectToken
         parameters["subject_token_type"] = subjectTokenType
         parameters["audience"] = audience
         parameters["scope"] = scope
-        return self.tokenExchange().parameters(parameters)
+        return self.token().parameters(parameters)
     }
+
 }

Auth0/Authentication.swift

@@ -410,22 +410,6 @@ public protocol Authentication: Trackable, Loggable {
      */
     func userInfo(withAccessToken accessToken: String) -> Request<UserInfo, AuthenticationError>
 
-    /**
-     Perform a OAuth2 token request against Auth0.
-
-     ```
-     Auth0
-        .authentication(clientId: clientId, domain: "samples.auth0.com")
-        .tokenExchange()
-        .parameters(["key": "value"])
-        .start { print($0) }
-     ```
-
-     - returns: a request that will yield Auth0 user's credentials
-     - seeAlso: exchangeCode(codeVerifier:, redirectURI:) for PKCE
-     */
-    func tokenExchange() -> Request<Credentials, AuthenticationError>
-
     /**
      Performs the last step of Proof Key for Code Exchange [RFC 7636](https://tools.ietf.org/html/rfc7636).
 
@@ -434,7 +418,7 @@ public protocol Authentication: Trackable, Loggable {
      ```
      Auth0
         .authentication(clientId: clientId, domain: "samples.auth0.com")
-        .tokenExchange(withCode: "a code", codeVerifier: "code verifier", redirectURI: "https://samples.auth0.com/callback")
+        .codeExchange(withCode: "a code", codeVerifier: "code verifier", redirectURI: "https://samples.auth0.com/callback")
         .start { print($0) }
      ```
 
@@ -445,7 +429,7 @@ public protocol Authentication: Trackable, Loggable {
      - returns: a request that will yield Auth0 user's credentials
      - seeAlso: https://tools.ietf.org/html/rfc7636
      */
-    func tokenExchange(withCode code: String, codeVerifier: String, redirectURI: String) -> Request<Credentials, AuthenticationError>
+    func codeExchange(withCode code: String, codeVerifier: String, redirectURI: String) -> Request<Credentials, AuthenticationError>
 
     /**
      Renew user's credentials with a refresh_token grant for `/oauth/token`

Auth0/OAuth2Grant.swift

@@ -77,7 +77,7 @@ struct PKCE: OAuth2Grant {
                                                        nonce: self.defaults["nonce"],
                                                        organization: self.organization)
         authentication
-            .tokenExchange(withCode: code, codeVerifier: verifier, redirectURI: redirectUrlString)
+            .codeExchange(withCode: code, codeVerifier: verifier, redirectURI: redirectUrlString)
             .start { result in
                 switch result {
                 case .failure(let error) where error.localizedDescription == "Unauthorized":

Auth0Tests/AuthenticationSpec.swift

@@ -1006,7 +1006,7 @@ class AuthenticationSpec: QuickSpec {
             it("should exchange code for tokens") {
                 stub(condition: isToken(Domain) && hasAtLeast(["code": code, "code_verifier": codeVerifier, "grant_type": "authorization_code", "redirect_uri": redirectURI])) { _ in return authResponse(accessToken: AccessToken, idToken: IdToken) }.name = "Code Exchange Auth"
                 waitUntil(timeout: Timeout) { done in
-                    auth.tokenExchange(withCode: code, codeVerifier: codeVerifier, redirectURI: redirectURI).start { result in
+                    auth.codeExchange(withCode: code, codeVerifier: codeVerifier, redirectURI: redirectURI).start { result in
                         expect(result).to(haveCredentials(AccessToken, IdToken))
                         done()
                     }
@@ -1019,7 +1019,7 @@ class AuthenticationSpec: QuickSpec {
                     let description = "Invalid code"
                     let invalidCode = "return invalid code"
                     stub(condition: isToken(Domain) && hasAtLeast(["code": invalidCode])) { _ in return authFailure(code: code, description: description) }.name = "Invalid Code"
-                    auth.tokenExchange(withCode: invalidCode, codeVerifier: codeVerifier, redirectURI: redirectURI).start { result in
+                    auth.codeExchange(withCode: invalidCode, codeVerifier: codeVerifier, redirectURI: redirectURI).start { result in
                         expect(result).to(haveAuthenticationError(code: code, description: description))
                         done()
                     }

V2_MIGRATION_GUIDE.md

@@ -97,6 +97,20 @@ Use `createUser(email:username:password:connection:userMetadata:rootAttributes:`
 
 Use `userInfo(withAccessToken:)` instead.
 
+#### `tokenExchange(withParameters:)`
+
+Use `codeExchange(withCode:codeVerifier:redirectURI:)` instead. To pass custom parameters, use the `parameters(_:)` method from `Request`:
+
+```swift
+Auth0
+    .authentication()
+    .codeExchange(withCode: code, codeVerifier: codeVerifier, redirectURI: redirectURI) 
+    .parameters(["key": "value"]) // 👈🏻
+    .start { result in
+        // ...
+    }
+```
+
 #### `tokenExchange(withAppleAuthorizationCode:scope:audience:fullName:)`
 
 Use `login(appleAuthorizationCode:fullName:profile:audience:scope:)` instead. 
@@ -298,21 +312,24 @@ These properties were removed:
 
 The Authentication API client methods will now only yield errors of type `AuthenticationError`. The underlying error (if any) is available via the `cause: Error?` property of the `AuthenticationError`.
 
+#### Renamed `tokenExchange(withCode:codeVerifier:redirectURI:)`
+
+The method `tokenExchange(withCode:codeVerifier:redirectURI:)` was renamed to `codeExchange(withCode:codeVerifier:redirectURI:)`.
+
 #### Removed `parameters` parameter
 
 The following methods lost the `parameters` parameter:
 
 - `login(phoneNumber:code:audience:scope:)`
 - `login(usernameOrEmail:password:realm:audience:scope:)`
 - `loginDefaultDirectory(withUsername:password:audience:scope:)`
-- `tokenExchange()`
 
 To pass custom parameters to those (or any) method in the Authentication client, use the `parameters(_:)` method from `Request`:
 
 ```swift
 Auth0
     .authentication()
-    .tokenExchange() // Returns a Request
+    .renew(withRefreshToken: refreshToken) // Returns a Request
     .parameters(["key": "value"]) // 👈🏻
     .start { result in
         // ...