Patch Peter-Schorn/SpotifyAPIExampleApp to use Authorization Code Flow with PKCE, for users of Peter-Schorn/SpotifyAPI

SpotifyAPIExampleApp-PKCE.patch

diff -crB -x S SpotifyAPIExampleApp-main/SpotifyAPIExampleApp/Model/Spotify.swift SpotifyAPIExampleApp-PKCE/SpotifyAPIExampleApp/Model/Spotify.swift
*** SpotifyAPIExampleApp-main/SpotifyAPIExampleApp/Model/Spotify.swift	Thu Feb 16 22:38:40 2023
--- SpotifyAPIExampleApp-PKCE/SpotifyAPIExampleApp/Model/Spotify.swift	Tue Jan 23 11:35:44 2024
***************
*** 22,35 ****
          fatalError("Could not find 'CLIENT_ID' in environment variables")
      }()
      
-     private static let clientSecret: String = {
-         if let clientSecret = ProcessInfo.processInfo
-                 .environment["CLIENT_SECRET"] {
-             return clientSecret
-         }
-         fatalError("Could not find 'CLIENT_SECRET' in environment variables")
-     }()
-     
      /// The key in the keychain that is used to store the authorization
      /// information: "authorizationManager".
      let authorizationManagerKey = "authorizationManager"
--- 22,27 ----
***************
*** 39,44 ****
--- 31,39 ----
      let loginCallbackURL = URL(
          string: "spotify-api-example-app://login-callback"
      )!
+ 
+ 	let codeVerifier = String.randomURLSafe(length: 128)
+ 	var codeChallenge: String { String.makeCodeChallenge(codeVerifier: codeVerifier) }
      
      /// A cryptographically-secure random string used to ensure than an incoming
      /// redirect from Spotify was the result of a request made by this app, and
***************
*** 78,86 ****
      /// An instance of `SpotifyAPI` that you use to make requests to the Spotify
      /// web API.
      let api = SpotifyAPI(
!         authorizationManager: AuthorizationCodeFlowManager(
!             clientId: Spotify.clientId,
!             clientSecret: Spotify.clientSecret
          )
      )
      
--- 73,80 ----
      /// An instance of `SpotifyAPI` that you use to make requests to the Spotify
      /// web API.
      let api = SpotifyAPI(
!         authorizationManager: AuthorizationCodeFlowPKCEManager(
!             clientId: Spotify.clientId
          )
      )
      
***************
*** 116,122 ****
              do {
                  // Try to decode the data.
                  let authorizationManager = try JSONDecoder().decode(
!                     AuthorizationCodeFlowManager.self,
                      from: authManagerData
                  )
                  print("found authorization information in keychain")
--- 110,116 ----
              do {
                  // Try to decode the data.
                  let authorizationManager = try JSONDecoder().decode(
!                     AuthorizationCodeFlowPKCEManager.self,
                      from: authManagerData
                  )
                  print("found authorization information in keychain")
***************
*** 161,171 ****
          
          let url = self.api.authorizationManager.makeAuthorizationURL(
              redirectURI: self.loginCallbackURL,
-             showDialog: true,
              // This same value **MUST** be provided for the state parameter of
              // `authorizationManager.requestAccessAndRefreshTokens(redirectURIWithQuery:state:)`.
              // Otherwise, an error will be thrown.
              state: self.authorizationState,
              scopes: [
                  .userReadPlaybackState,
                  .userModifyPlaybackState,
--- 155,165 ----
          
          let url = self.api.authorizationManager.makeAuthorizationURL(
              redirectURI: self.loginCallbackURL,
              // This same value **MUST** be provided for the state parameter of
              // `authorizationManager.requestAccessAndRefreshTokens(redirectURIWithQuery:state:)`.
              // Otherwise, an error will be thrown.
+             codeChallenge: codeChallenge,
              state: self.authorizationState,
              scopes: [
                  .userReadPlaybackState,
                  .userModifyPlaybackState,
diff -crB -x S SpotifyAPIExampleApp-main/SpotifyAPIExampleApp/Views/RootView.swift SpotifyAPIExampleApp-PKCE/SpotifyAPIExampleApp/Views/RootView.swift
*** SpotifyAPIExampleApp-main/SpotifyAPIExampleApp/Views/RootView.swift	Thu Feb 16 22:38:40 2023
--- SpotifyAPIExampleApp-PKCE/SpotifyAPIExampleApp/Views/RootView.swift	Tue Jan 23 11:36:20 2024
***************
*** 63,68 ****
--- 63,71 ----
          // refresh tokens.
          spotify.api.authorizationManager.requestAccessAndRefreshTokens(
              redirectURIWithQuery: url,
+             // Must match the code verifier that was used to generate the
+             // code challenge when creating the authorization URL.
+             codeVerifier: spotify.codeVerifier,
              // This value must be the same as the one used to create the
              // authorization URL. Otherwise, an error will be thrown.
              state: spotify.authorizationState