test(scum): cover supported companion adapters

plugins/examples/scum-server-plugin/companion/dispatcher.go

@@ -2,6 +2,7 @@ package companion
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"strings"
 	"sync"
@@ -20,6 +21,11 @@ type SafeAdapter interface {
 	SpawnVehicle(context.Context, map[string]any) (map[string]any, error)
 }
 
+// ServerBoundAdapter lets a versioned adapter prove that it is configured for
+// the same server as the registration which declared handler availability.
+// Generic test adapters do not need this optional assertion.
+type ServerBoundAdapter interface{ ServerBinding() string }
+
 type HandlerAvailability struct {
 	BoundServerID string
 	ServerVersion string
@@ -28,10 +34,11 @@ type HandlerAvailability struct {
 }
 type CommandHandler func(context.Context, map[string]any) (map[string]any, error)
 type HandlerRegistry struct {
-	availability HandlerAvailability
-	handlers     map[string]CommandHandler
-	mu           sync.Mutex
-	completed    map[string]CommandResult
+	availability  HandlerAvailability
+	handlers      map[string]CommandHandler
+	adapterServer string
+	mu            sync.Mutex
+	completed     map[string]CommandResult
 }
 
 func NewHandlerRegistry(availability HandlerAvailability, adapter SafeAdapter) *HandlerRegistry {
@@ -39,6 +46,9 @@ func NewHandlerRegistry(availability HandlerAvailability, adapter SafeAdapter) *
 	if adapter == nil {
 		return registry
 	}
+	if bound, ok := adapter.(ServerBoundAdapter); ok {
+		registry.adapterServer = bound.ServerBinding()
+	}
 	registry.handlers["config.read"] = func(ctx context.Context, _ map[string]any) (map[string]any, error) {
 		return adapter.ReadConfiguration(ctx)
 	}
@@ -71,7 +81,7 @@ func (registry *HandlerRegistry) Execute(ctx context.Context, command ClaimedCom
 	if err := validateDeclaredCommandAt(command, time.Now); err != nil {
 		return unsupportedResult("validation-failed"), nil
 	}
-	if strings.TrimSpace(registry.availability.BoundServerID) == "" || !registry.availability.Approved || !registry.availability.Capabilities[command.CommandType] {
+	if strings.TrimSpace(registry.availability.BoundServerID) == "" || !registry.adapterBindingMatches() || !registry.availability.Approved || !registry.availability.Capabilities[command.CommandType] {
 		return unsupportedResult("unsupported"), nil
 	}
 	handler, exists := registry.handlers[command.CommandType]
@@ -80,6 +90,9 @@ func (registry *HandlerRegistry) Execute(ctx context.Context, command ClaimedCom
 	}
 	payload, err := handler(ctx, command.Payload)
 	if err != nil {
+		if errors.Is(err, errAdapterUnsupported) {
+			return unsupportedResult("unsupported"), nil
+		}
 		return CommandResult{Status: "failed", Summary: "typed adapter failed", Payload: map[string]any{"result": "failed"}}, nil
 	}
 	result := CommandResult{Status: "succeeded", Summary: "typed adapter completed", Payload: redactTypedPayload(payload)}
@@ -89,6 +102,10 @@ func (registry *HandlerRegistry) Execute(ctx context.Context, command ClaimedCom
 	return result, nil
 }
 
+func (registry *HandlerRegistry) adapterBindingMatches() bool {
+	return registry.adapterServer == "" || registry.adapterServer == registry.availability.BoundServerID
+}
+
 func validateDeclaredCommandAt(command ClaimedCommand, now func() time.Time) error {
 	if command.ID == "" || command.ProfileKey != ProfileKey || command.FencingToken == 0 || command.Payload == nil || command.LeaseExpiresAt.IsZero() || command.ExpiresAt.IsZero() || !now().Before(command.LeaseExpiresAt) || !now().Before(command.ExpiresAt) {
 		return fmt.Errorf("invalid command")