Better validation checks for production

lib/courrier/email/provider.rb

@@ -40,8 +40,8 @@ def initialize(provider: nil, api_key: nil, options: {}, provider_options: {}, c
       end
 
       def deliver
-        raise Courrier::ConfigurationError, "`provider` and `api_key` must be configured for production environment" if configuration_missing_in_production?
-        raise Courrier::ConfigurationError, "Unknown provider. Choose one of `#{comma_separated_providers}` or provide your own." if @provider.nil? || @provider.to_s.strip.empty?
+        raise Courrier::ConfigurationError, "Unknown provider. Choose one of `#{comma_separated_providers}` or provide your own." if provider_invalid?
+        raise Courrier::ConfigurationError, "API key must be configured for #{@provider} provider in production environment" if configuration_missing_in_production?
 
         provider_class.new(
           api_key: @api_key,
@@ -53,8 +53,12 @@ def deliver
 
       private
 
+      def provider_invalid?
+        @provider.nil? || @provider.to_s.strip.empty?
+      end
+
       def configuration_missing_in_production?
-        production? && required_attributes_blank?
+        production? && api_key_required_providers? && api_key_blank?
       end
 
       def comma_separated_providers = PROVIDERS.keys.join(", ")
@@ -65,7 +69,13 @@ def provider_class
         Object.const_get(@provider)
       end
 
-      def required_attributes_blank? = @api_key.empty?
+      def api_key_required_providers?
+        !%w[logger inbox].include?(@provider.to_s)
+      end
+
+      def api_key_blank?
+        @api_key.nil? || @api_key.to_s.strip.empty?
+      end
 
       def production?
         defined?(Rails) && Rails.env.production?

test/courrier/email/provider_test.rb

@@ -44,7 +44,7 @@ def test_raises_error_in_production_without_config
       provider.deliver
     end
 
-    assert_equal "`provider` and `api_key` must be configured for production environment", error.message
+    assert_equal "API key must be configured for mailgun provider in production environment", error.message
   end
 
   def test_initializes_correct_provider_class