feat(scanner): add Scanner.ArtistSplitExceptions config option

conf/configuration.go

@@ -153,17 +153,18 @@ type configOptions struct {
 }
 
 type scannerOptions struct {
-	Enabled            bool
-	Schedule           string
-	WatcherWait        time.Duration
-	ScanOnStartup      bool
-	Extractor          string
-	ArtistJoiner       string
-	GenreSeparators    string // Deprecated: Use Tags.genre.Split instead
-	GroupAlbumReleases bool   // Deprecated: Use PID.Album instead
-	FollowSymlinks     bool   // Whether to follow symlinks when scanning directories
-	IgnoreDotFolders   bool   // Whether to ignore folders whose name starts with a dot when scanning
-	PurgeMissing       string // Values: "never", "always", "full"
+	Enabled               bool
+	Schedule              string
+	WatcherWait           time.Duration
+	ScanOnStartup         bool
+	Extractor             string
+	ArtistJoiner          string
+	ArtistSplitExceptions []string // Artist names never split by tag separators
+	GenreSeparators       string   // Deprecated: Use Tags.genre.Split instead
+	GroupAlbumReleases    bool     // Deprecated: Use PID.Album instead
+	FollowSymlinks        bool     // Whether to follow symlinks when scanning directories
+	IgnoreDotFolders      bool     // Whether to ignore folders whose name starts with a dot when scanning
+	PurgeMissing          string   // Values: "never", "always", "full"
 }
 
 type transcodingOptions struct {
@@ -819,6 +820,7 @@ func setViperDefaults() {
 	viper.SetDefault("scanner.watcherwait", consts.DefaultWatcherWait)
 	viper.SetDefault("scanner.scanonstartup", true)
 	viper.SetDefault("scanner.artistjoiner", consts.ArtistJoiner)
+	viper.SetDefault("scanner.artistsplitexceptions", []string{})
 	viper.SetDefault("scanner.genreseparators", "")
 	viper.SetDefault("scanner.groupalbumreleases", false)
 	viper.SetDefault("scanner.followsymlinks", true)

model/tag_mappings.go

@@ -129,6 +129,28 @@ func compileExceptionsRegex(exceptions []string) *regexp.Regexp {
 	return rx
 }
 
+var artistSplitExceptions struct {
+	sync.Mutex
+	key string
+	rx  *regexp.Regexp
+}
+
+// ArtistSplitExceptionsRx returns the regex for Scanner.ArtistSplitExceptions,
+// or nil if none are configured. Compiled lazily (config hooks only run once
+// per process, before tests can override the option) and cached until the
+// configured list changes.
+func ArtistSplitExceptionsRx() *regexp.Regexp {
+	c := &artistSplitExceptions
+	c.Lock()
+	defer c.Unlock()
+	key := strings.Join(conf.Server.Scanner.ArtistSplitExceptions, "\x00")
+	if c.key != key {
+		c.key = key
+		c.rx = compileExceptionsRegex(conf.Server.Scanner.ArtistSplitExceptions)
+	}
+	return c.rx
+}
+
 type TagType string
 
 const (

model/tag_mappings_test.go

@@ -1,6 +1,8 @@
 package model
 
 import (
+	"github.com/navidrome/navidrome/conf"
+	"github.com/navidrome/navidrome/conf/configtest"
 	. "github.com/onsi/ginkgo/v2"
 	. "github.com/onsi/gomega"
 )
@@ -141,4 +143,33 @@ var _ = Describe("TagConf", func() {
 			Expect(rx.MatchString("IRON AND WINE")).To(BeTrue())
 		})
 	})
+
+	Describe("ArtistSplitExceptionsRx", func() {
+		BeforeEach(func() {
+			DeferCleanup(configtest.SetupConfig())
+		})
+
+		It("returns nil when no exceptions are configured", func() {
+			conf.Server.Scanner.ArtistSplitExceptions = nil
+			Expect(ArtistSplitExceptionsRx()).To(BeNil())
+		})
+
+		It("compiles the configured exceptions", func() {
+			conf.Server.Scanner.ArtistSplitExceptions = []string{"Iron and Wine"}
+			rx := ArtistSplitExceptionsRx()
+			Expect(rx).ToNot(BeNil())
+			Expect(rx.MatchString("iron and wine")).To(BeTrue())
+		})
+
+		It("caches the compiled regex until the configuration changes", func() {
+			conf.Server.Scanner.ArtistSplitExceptions = []string{"Iron and Wine"}
+			first := ArtistSplitExceptionsRx()
+			Expect(ArtistSplitExceptionsRx()).To(BeIdenticalTo(first))
+
+			conf.Server.Scanner.ArtistSplitExceptions = []string{"AC/DC"}
+			second := ArtistSplitExceptionsRx()
+			Expect(second).ToNot(BeIdenticalTo(first))
+			Expect(second.MatchString("AC/DC")).To(BeTrue())
+		})
+	})
 })