Refactor handler loading error messages for clarity and consistency. Bubble up error messages

Author: GrantBirki

lib/hooks/app/helpers.rb

@@ -84,12 +84,8 @@ def load_handler(handler_class_name)
         # - Thread Safety: Avoids race conditions from shared instance state
         # - Performance: Handler instantiation is fast; reusing instances provides minimal gain
         # - Memory: Allows garbage collection of short-lived objects (Ruby GC optimization)
-        begin
-          handler_class = Core::PluginLoader.get_handler_plugin(handler_class_name)
-          return handler_class.new
-        rescue StandardError => e
-          error!("failed to get handler '#{handler_class_name}': #{e.message}", 500)
-        end
+        handler_class = Core::PluginLoader.get_handler_plugin(handler_class_name)
+        return handler_class.new
       end
 
       private

spec/acceptance/acceptance_tests.rb

@@ -430,6 +430,20 @@ def expired_unix_timestamp(seconds_ago = 600)
       end
     end
 
+    describe "does_not_exist" do
+      it "sends a POST request to the /webhooks/does_not_exist endpoint and it fails because the handler does not exist" do
+        payload = {}.to_json
+        headers = {}
+        response = make_request(:post, "/webhooks/does_not_exist", payload, headers)
+        expect_response(response, Net::HTTPInternalServerError, /Handler plugin 'DoesNotExist' not found/)
+        body = parse_json_response(response)
+        expect(body["error"]).to eq("server_error")
+        expect(body["message"]).to match(
+          /Handler plugin 'DoesNotExist' not found. Available handlers: DefaultHandler,.*/
+        )
+      end
+    end
+
     describe "okta setup" do
       it "sends a POST request to the /webhooks/okta_webhook_setup endpoint and it fails because it is not a GET" do
         payload = {}.to_json

spec/acceptance/config/endpoints/does_not_exist.yml

@@ -0,0 +1,2 @@
+path: /does_not_exist
+handler: DoesNotExist

spec/unit/lib/hooks/app/helpers_security_spec.rb

@@ -38,7 +38,7 @@ def env
       it "returns error indicating handler not found" do
         expect do
           instance.load_handler("NonexistentHandler")
-        end.to raise_error(StandardError, /failed to get handler.*not found/)
+        end.to raise_error(StandardError, /Handler plugin.*not found/)
       end
 
       it "returns error for any handler class name when no plugins loaded" do
@@ -47,7 +47,7 @@ def env
         handler_names.each do |name|
           expect do
             instance.load_handler(name)
-          end.to raise_error(StandardError, /failed to get handler.*not found/)
+          end.to raise_error(StandardError, /Handler plugin.*not found/)
         end
       end
     end

spec/unit/lib/hooks/app/helpers_spec.rb

@@ -296,7 +296,7 @@ def error!(message, code)
       it "returns error indicating handler not found" do
         expect do
           helper.load_handler("NonexistentHandler")
-        end.to raise_error(StandardError, /failed to get handler.*not found/)
+        end.to raise_error(StandardError, /Handler plugin.*not found/)
       end
     end