add a test for scan tag errors

server/mockfs/mockfs.go

@@ -75,6 +75,10 @@ func (m *MockFS) ScanAndClean() *scanner.Context {
 	return ctx
 }
 
+func (m *MockFS) ScanAndCleanErr() (*scanner.Context, error) {
+	return m.scanner.ScanAndClean(scanner.ScanOptions{})
+}
+
 func (m *MockFS) ResetDates() {
 	t := time.Date(2020, 0, 0, 0, 0, 0, 0, time.UTC)
 	if err := m.db.Model(db.Album{}).Updates(db.Album{CreatedAt: t, UpdatedAt: t, ModifiedAt: t}).Error; err != nil {
@@ -119,6 +123,10 @@ func (m *MockFS) addItems(prefix string, covers bool) {
 	}
 }
 
+func (m *MockFS) NumTracks() int {
+	return len(m.tagReader.paths)
+}
+
 func (m *MockFS) RemoveAll(path string) {
 	abspath := filepath.Join(m.dir, path)
 	if err := os.RemoveAll(abspath); err != nil {

server/scanner/scanner.go

@@ -101,7 +101,7 @@ func (s *Scanner) ScanAndClean(opts ScanOptions) (*Context, error) {
 	}
 
 	if c.errs.Len() > 0 {
-		return nil, c.errs
+		return c, c.errs
 	}
 
 	return c, nil

server/scanner/scanner_test.go

@@ -1,6 +1,7 @@
 package scanner_test
 
 import (
+	"errors"
 	"fmt"
 	"io/ioutil"
 	"log"
@@ -12,8 +13,10 @@ import (
 	_ "github.com/jinzhu/gorm/dialects/sqlite"
 	"github.com/matryer/is"
 
+	"go.senan.xyz/gonic/multierr"
 	"go.senan.xyz/gonic/server/db"
 	"go.senan.xyz/gonic/server/mockfs"
+	"go.senan.xyz/gonic/server/scanner"
 )
 
 func TestMain(m *testing.M) {
@@ -32,7 +35,7 @@ func TestTableCounts(t *testing.T) {
 
 	var tracks int
 	is.NoErr(m.DB().Model(&db.Track{}).Count(&tracks).Error) // not all tracks
-	is.Equal(tracks, 3*3*3)                                  // not all tracks
+	is.Equal(tracks, m.NumTracks())
 
 	var albums int
 	is.NoErr(m.DB().Model(&db.Album{}).Count(&albums).Error) // not all albums
@@ -483,3 +486,31 @@ func TestArtistHasCover(t *testing.T) {
 	is.NoErr(m.DB().Where("name=?", "artist-0").First(&artistWithout).Error)
 	is.Equal(artistWithout.Cover, "")
 }
+
+func TestTagErrors(t *testing.T) {
+	t.Parallel()
+	is := is.New(t)
+	m := mockfs.New(t)
+	defer m.CleanUp()
+
+	m.AddItemsWithCovers()
+	m.SetTags("artist-1/album-0/track-0.flac", func(tags *mockfs.Tags) error {
+		return scanner.ErrReadingTags
+	})
+	m.SetTags("artist-1/album-1/track-0.flac", func(tags *mockfs.Tags) error {
+		return scanner.ErrReadingTags
+	})
+
+	var errs *multierr.Err
+	ctx, err := m.ScanAndCleanErr()
+	is.True(errors.As(err, &errs))
+	is.Equal(errs.Len(), 2)                            // we have 2 dir errors
+	is.Equal(ctx.SeenTracks(), m.NumTracks()-(3*2))    // we saw all tracks bar 2 album contents
+	is.Equal(ctx.SeenTracksNew(), m.NumTracks()-(3*2)) // we have all tracks bar 2 album contents
+
+	ctx, err = m.ScanAndCleanErr()
+	is.True(errors.As(err, &errs))
+	is.Equal(errs.Len(), 2)                         // we have 2 dir errors
+	is.Equal(ctx.SeenTracks(), m.NumTracks()-(3*2)) // we saw all tracks bar 2 album contents
+	is.Equal(ctx.SeenTracksNew(), 0)                // we have no new tracks
+}