Cleaned up documentation and removed stubs and TODOs throughout the application

sinks/registry.go

@@ -2,6 +2,7 @@ package sinks
 
 import (
 	"fmt"
+	"strings"
 
 	"gitea.maximumdirect.net/ejr/feedkit/config"
 )
@@ -21,13 +22,40 @@ func NewRegistry() *Registry {
 }
 
 func (r *Registry) Register(driver string, f Factory) {
+	if r == nil {
+		panic("sinks.Registry.Register: registry cannot be nil")
+	}
+	driver = strings.TrimSpace(driver)
+	if driver == "" {
+		panic("sinks.Registry.Register: driver cannot be empty")
+	}
+	if f == nil {
+		panic(fmt.Sprintf("sinks.Registry.Register: factory cannot be nil (driver=%q)", driver))
+	}
+	if r.byDriver == nil {
+		r.byDriver = map[string]Factory{}
+	}
+	if _, exists := r.byDriver[driver]; exists {
+		panic(fmt.Sprintf("sinks.Registry.Register: driver %q already registered", driver))
+	}
 	r.byDriver[driver] = f
 }
 
 func (r *Registry) Build(cfg config.SinkConfig) (Sink, error) {
-	f, ok := r.byDriver[cfg.Driver]
-	if !ok {
-		return nil, fmt.Errorf("unknown sink driver: %q", cfg.Driver)
+	if r == nil {
+		return nil, fmt.Errorf("sinks registry is nil")
 	}
-	return f(cfg)
+	driver := strings.TrimSpace(cfg.Driver)
+	f, ok := r.byDriver[driver]
+	if !ok {
+		return nil, fmt.Errorf("unknown sink driver: %q", driver)
+	}
+	sink, err := f(cfg)
+	if err != nil {
+		return nil, fmt.Errorf("build sink %q: %w", driver, err)
+	}
+	if sink == nil {
+		return nil, fmt.Errorf("build sink %q: factory returned nil sink", driver)
+	}
+	return sink, nil
 }