Bugfix: Improve error messaging in Twitter app configuration flow

lib/external_credential/twitter.rb

@@ -29,11 +29,14 @@ class ExternalCredential::Twitter
     begin
       request_token = consumer.get_request_token(oauth_callback: ExternalCredential.callback_url('twitter'))
     rescue => e
-      if e.message == '403 Forbidden'
-        raise "#{e.message}, maybe credentials wrong or callback_url for application wrong configured."
+      case e.message
+      when '401 Authorization Required'
+        raise "#{e.message} (Invalid credentials may be to blame.)"
+      when '403 Forbidden'
+        raise "#{e.message} (Your app's callback URL configuration on developer.twitter.com may be to blame.)"
+      else
+        raise
       end
-
-      raise e
     end
 
     {

spec/requests/external_credentials_spec.rb

@@ -224,7 +224,9 @@ RSpec.describe 'External Credentials', type: :request do
 
           include_examples 'for failure cases' do
             let(:status) { :ok }
-            let(:error_message) { '401 Authorization Required' }
+            let(:error_message) { <<~ERR.chomp }
+              401 Authorization Required (Invalid credentials may be to blame.)
+            ERR
           end
         end
 
@@ -234,7 +236,7 @@ RSpec.describe 'External Credentials', type: :request do
           include_examples 'for failure cases' do
             let(:status) { :ok }
             let(:error_message) { <<~ERR.chomp }
-              403 Forbidden, maybe credentials wrong or callback_url for application wrong configured.
+              403 Forbidden (Your app's callback URL configuration on developer.twitter.com may be to blame.)
             ERR
           end
         end
@@ -343,7 +345,9 @@ RSpec.describe 'External Credentials', type: :request do
 
           include_examples 'for failure cases' do
             let(:status) { :internal_server_error }
-            let(:error_message) { '401 Authorization Required' }
+            let(:error_message) { <<~ERR.chomp }
+              401 Authorization Required (Invalid credentials may be to blame.)
+            ERR
           end
         end
 
@@ -353,7 +357,7 @@ RSpec.describe 'External Credentials', type: :request do
           include_examples 'for failure cases' do
             let(:status) { :internal_server_error }
             let(:error_message) { <<~ERR.chomp }
-              403 Forbidden, maybe credentials wrong or callback_url for application wrong configured.
+              403 Forbidden (Your app's callback URL configuration on developer.twitter.com may be to blame.)
             ERR
           end
         end