fix scanner missing library errors

internal/service/scanner_incremental_test.go

@@ -1,12 +1,14 @@
 package service
 
 import (
+	"errors"
 	"os"
 	"path/filepath"
 	"testing"
 	"time"
 
 	"go.uber.org/zap"
+	"gorm.io/gorm"
 
 	"github.com/ShukeBta/MediaStationGo/internal/config"
 	"github.com/ShukeBta/MediaStationGo/internal/model"
@@ -61,6 +63,30 @@ func TestIngestPathAddsSingleFile(t *testing.T) {
 	}
 }
 
+func TestScanLibraryReturnsNotFoundForMissingLibrary(t *testing.T) {
+	sc, _ := newScannerTestEnv(t)
+
+	res, err := sc.ScanLibrary(t.Context(), "missing-library")
+	if err == nil {
+		t.Fatalf("ScanLibrary() error = nil, result = %#v", res)
+	}
+	if !errors.Is(err, gorm.ErrRecordNotFound) && err.Error() != "library not found" {
+		t.Fatalf("ScanLibrary() error = %v, want not found", err)
+	}
+}
+
+func TestIngestPathReturnsNotFoundForMissingLibrary(t *testing.T) {
+	sc, _ := newScannerTestEnv(t)
+
+	added, err := sc.IngestPath(t.Context(), "missing-library", filepath.Join(t.TempDir(), "movie.mkv"))
+	if err == nil {
+		t.Fatalf("IngestPath() error = nil, added = %v", added)
+	}
+	if !errors.Is(err, gorm.ErrRecordNotFound) && err.Error() != "library not found" {
+		t.Fatalf("IngestPath() error = %v, want not found", err)
+	}
+}
+
 func TestScanLibraryReadsLocalSTRMTarget(t *testing.T) {
 	sc, repos := newScannerTestEnv(t)
 	root := t.TempDir()

internal/service/scanner_scan.go

@@ -68,9 +68,12 @@ func (s *ScannerService) TryBeginLocalScan(libraryID string) (func(), bool) {
 
 func (s *ScannerService) scanLibrary(ctx context.Context, libraryID string, autoScrape bool) (*ScanResult, error) {
 	lib, err := s.repo.Library.FindByID(ctx, libraryID)
-	if err != nil || lib == nil {
+	if err != nil {
 		return nil, err
 	}
+	if lib == nil {
+		return nil, errors.New("library not found")
+	}
 	if mount, ok := ParseCloudLibraryMount(lib.Path); ok {
 		return s.scanMountedCloudLibrary(ctx, lib, mount, autoScrape)
 	}
@@ -229,9 +232,12 @@ func (s *ScannerService) finishLocalLibraryScan(ctx context.Context, lib *model.
 // added or updated.
 func (s *ScannerService) IngestPath(ctx context.Context, libraryID, path string) (bool, error) {
 	lib, err := s.repo.Library.FindByID(ctx, libraryID)
-	if err != nil || lib == nil {
+	if err != nil {
 		return false, err
 	}
+	if lib == nil {
+		return false, errors.New("library not found")
+	}
 	root, err := s.localLibraryRootForPath(ctx, lib, path)
 	if err != nil || root == nil {
 		return false, err