fix: EventEmitter doc accuracy, registerPluginTrigger deterministic failure, remove duplicate admin tests

admin/admin_test.go

@@ -188,29 +188,6 @@ func TestMergeInto_WithRealAdminConfig(t *testing.T) {
 	}
 }
 
-func TestLoadConfig_Parses(t *testing.T) {
-	cfg, err := LoadConfig()
-	if err != nil {
-		t.Fatalf("LoadConfig: %v", err)
-	}
-	if cfg == nil {
-		t.Fatal("expected non-nil config")
-	}
-	if len(cfg.Modules) == 0 {
-		t.Error("expected at least one module in admin config")
-	}
-}
-
-func TestLoadConfigRaw_NonEmpty(t *testing.T) {
-	raw, err := LoadConfigRaw()
-	if err != nil {
-		t.Fatalf("LoadConfigRaw: %v", err)
-	}
-	if len(raw) == 0 {
-		t.Error("expected non-empty raw config data")
-	}
-}
-
 func TestLoadConfig_HasExpectedModules(t *testing.T) {
 	cfg, err := LoadConfig()
 	if err != nil {

engine.go

@@ -218,7 +218,9 @@ func (e *StdEngine) LoadPlugin(p plugin.EnginePlugin) error {
 	for triggerType, factory := range p.TriggerFactories() {
 		// Delegate to the bridge helper; triggers are interfaces.Trigger values
 		// (module.Trigger is a type alias for interfaces.Trigger).
-		e.registerPluginTrigger(triggerType, factory)
+		if err := e.registerPluginTrigger(triggerType, factory); err != nil {
+			return fmt.Errorf("load plugin: %w", err)
+		}
 	}
 
 	// Register pipeline trigger config wrappers from plugin (optional interface).

engine_module_bridge.go

@@ -84,15 +84,17 @@ func (e *StdEngine) registerPluginSteps(typeName string, stepFactory func(name s
 // Lives here to avoid a direct module.Trigger type assertion in engine.go.
 // Since module.Trigger is now an alias for interfaces.Trigger, the assertion
 // uses the canonical interface type.
-func (e *StdEngine) registerPluginTrigger(triggerType string, factory func() any) {
+// Returns an error when the factory returns a value that does not satisfy
+// interfaces.Trigger, so LoadPlugin can fail deterministically instead of
+// silently skipping the trigger and surfacing a confusing "no handler found"
+// error later at runtime.
+func (e *StdEngine) registerPluginTrigger(triggerType string, factory func() any) error {
 	result := factory()
 	trigger, ok := result.(interfaces.Trigger)
 	if !ok {
-		// Fail fast with a clear warning when a plugin misconfigures its trigger factory.
-		// This avoids silent failures that later surface as "no handler found" errors.
-		e.logger.Error(fmt.Sprintf("workflow: plugin trigger factory for %q returned non-Trigger type %T; trigger not registered", triggerType, result))
-		return
+		return fmt.Errorf("workflow: plugin trigger factory for %q returned non-Trigger type %T", triggerType, result)
 	}
 	e.triggerTypeMap[triggerType] = trigger.Name()
 	e.RegisterTrigger(trigger)
+	return nil
 }

interfaces/events.go

@@ -5,7 +5,7 @@ import (
 	"time"
 )
 
-// EventEmitter publishes workflow and step lifecycle events.
+// EventEmitter publishes workflow lifecycle events.
 // *module.WorkflowEventEmitter satisfies this interface.
 // All methods must be safe to call when no event bus is configured (no-ops).
 type EventEmitter interface {