feat: Add ability to specify single connection for try-login (#39)

internal/cli/try_login.go

@@ -24,6 +24,10 @@ const (
 )
 
 func tryLoginCmd(cli *cli) *cobra.Command {
+	var clientID string
+	var connectionName string
+	var reveal bool
+
 	cmd := &cobra.Command{
 		Use:   "try-login",
 		Short: "Try out your universal login box",
@@ -40,7 +44,6 @@ Launch a browser to try out your universal login box for the given client.
 			// "CLI Login Testing" client if none passed. This client is only
 			// used for testing login from the CLI and will be created if it
 			// does not exist.
-			clientID, _ := cmd.Flags().GetString("client-id")
 			if clientID == "" {
 				client, err := getOrCreateCLITesterClient(cli.api.Client)
 				if err != nil {
@@ -67,11 +70,15 @@ Launch a browser to try out your universal login box for the given client.
 			}
 
 			if client.GetInitiateLoginURI() != cliLoginTestingInitiateLoginURI {
+				if connectionName != "" {
+					cli.renderer.Warnf("Specific connections are not supported when using a non-default client, ignoring.")
+					cli.renderer.Warnf("You should ensure the connection you wish to test is enabled for the client you want to use in the Auth0 Dashboard.")
+				}
 				return open.URL(client.GetInitiateLoginURI())
 			}
 
 			// Build a login URL and initiate login in a browser window.
-			loginURL, err := buildInitiateLoginURL(tenant.Domain, client.GetClientID())
+			loginURL, err := buildInitiateLoginURL(tenant.Domain, client.GetClientID(), connectionName)
 			if err != nil {
 				return err
 			}
@@ -107,15 +114,15 @@ Launch a browser to try out your universal login box for the given client.
 				return err
 			}
 
-			reveal, _ := cmd.Flags().GetBool("reveal")
 			cli.renderer.TryLogin(userInfo, tokenResponse, reveal)
 			return nil
 		},
 	}
 
 	cmd.SetUsageTemplate(resourceUsageTemplate())
-	cmd.Flags().StringP("client-id", "c", "", "Client ID for which to test login.")
-	cmd.Flags().BoolP("reveal", "r", false, "⚠️  Reveal tokens after successful login.")
+	cmd.Flags().StringVarP(&clientID, "client-id", "c", "", "Client ID for which to test login.")
+	cmd.Flags().StringVarP(&connectionName, "connection", "", "", "Connection to test during login.")
+	cmd.Flags().BoolVarP(&reveal, "reveal", "r", false, "⚠️  Reveal tokens after successful login.")
 	return cmd
 }
 
@@ -146,7 +153,7 @@ func getOrCreateCLITesterClient(clientManager auth0.ClientAPI) (*management.Clie
 
 // buildInitiateLoginURL constructs a URL + query string that can be used to
 // initiate a login-flow from the CLI.
-func buildInitiateLoginURL(domain, clientID string) (string, error) {
+func buildInitiateLoginURL(domain, clientID, connectionName string) (string, error) {
 	var path string = "/authorize"
 
 	q := url.Values{}
@@ -156,6 +163,10 @@ func buildInitiateLoginURL(domain, clientID string) (string, error) {
 	q.Add("scope", cliLoginTestingScopes)
 	q.Add("redirect_uri", cliLoginTestingCallbackURL)
 
+	if connectionName != "" {
+		q.Add("connection", connectionName)
+	}
+
 	u := &url.URL{
 		Scheme:   "https",
 		Host:     domain,
@@ -171,20 +182,32 @@ func buildInitiateLoginURL(domain, clientID string) (string, error) {
 // `code` is extracted from the query string (if any), and returns it to the
 // caller.
 func waitForBrowserCallback() (string, error) {
-	codeCh := make(chan string)
+	type callback struct {
+		code           string
+		err            string
+		errDescription string
+	}
+
+	cbCh := make(chan *callback)
 	errCh := make(chan error)
 
 	m := http.NewServeMux()
 	s := http.Server{Addr: cliLoginTestingCallbackAddr, Handler: m}
 
 	m.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
-		authCode := r.URL.Query().Get("code")
-		if authCode == "" {
+		cb := &callback{
+			code:           r.URL.Query().Get("code"),
+			err:            r.URL.Query().Get("error"),
+			errDescription: r.URL.Query().Get("error_description"),
+		}
+
+		if cb.code == "" {
 			_, _ = w.Write([]byte("<p>&#10060; Unable to extract code from request, please try authenticating again</p>"))
 		} else {
 			_, _ = w.Write([]byte("<p>&#128075; You can close the window and go back to the CLI to see the user info and tokens</p>"))
 		}
-		codeCh <- authCode
+
+		cbCh <- cb
 	})
 
 	go func() {
@@ -194,12 +217,16 @@ func waitForBrowserCallback() (string, error) {
 	}()
 
 	select {
-	case code := <-codeCh:
+	case cb := <-cbCh:
 		ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
 		defer cancel()
+		defer func(c context.Context) { _ = s.Shutdown(ctx) }(ctx)
 
-		err := s.Shutdown(ctx)
-		return code, err
+		var err error
+		if cb.err != "" {
+			err = fmt.Errorf("%s: %s", cb.err, cb.errDescription)
+		}
+		return cb.code, err
 	case err := <-errCh:
 		return "", err
 	}