feat(scanner): implement file-based target passing for large target lists

Signed-off-by: Deluan <deluan@navidrome.org>

cmd/scan_test.go

@@ -0,0 +1,89 @@
+package cmd
+
+import (
+	"os"
+	"path/filepath"
+
+	"github.com/navidrome/navidrome/model"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("readTargetsFromFile", func() {
+	var tempDir string
+
+	BeforeEach(func() {
+		var err error
+		tempDir, err = os.MkdirTemp("", "navidrome-test-")
+		Expect(err).ToNot(HaveOccurred())
+	})
+
+	AfterEach(func() {
+		os.RemoveAll(tempDir)
+	})
+
+	It("reads valid targets from file", func() {
+		filePath := filepath.Join(tempDir, "targets.txt")
+		content := "1:Music/Rock\n2:Music/Jazz\n3:Classical\n"
+		err := os.WriteFile(filePath, []byte(content), 0600)
+		Expect(err).ToNot(HaveOccurred())
+
+		targets, err := readTargetsFromFile(filePath)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(targets).To(HaveLen(3))
+		Expect(targets[0]).To(Equal(model.ScanTarget{LibraryID: 1, FolderPath: "Music/Rock"}))
+		Expect(targets[1]).To(Equal(model.ScanTarget{LibraryID: 2, FolderPath: "Music/Jazz"}))
+		Expect(targets[2]).To(Equal(model.ScanTarget{LibraryID: 3, FolderPath: "Classical"}))
+	})
+
+	It("skips empty lines", func() {
+		filePath := filepath.Join(tempDir, "targets.txt")
+		content := "1:Music/Rock\n\n2:Music/Jazz\n\n"
+		err := os.WriteFile(filePath, []byte(content), 0600)
+		Expect(err).ToNot(HaveOccurred())
+
+		targets, err := readTargetsFromFile(filePath)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(targets).To(HaveLen(2))
+	})
+
+	It("trims whitespace", func() {
+		filePath := filepath.Join(tempDir, "targets.txt")
+		content := "  1:Music/Rock  \n\t2:Music/Jazz\t\n"
+		err := os.WriteFile(filePath, []byte(content), 0600)
+		Expect(err).ToNot(HaveOccurred())
+
+		targets, err := readTargetsFromFile(filePath)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(targets).To(HaveLen(2))
+		Expect(targets[0].FolderPath).To(Equal("Music/Rock"))
+		Expect(targets[1].FolderPath).To(Equal("Music/Jazz"))
+	})
+
+	It("returns error for non-existent file", func() {
+		_, err := readTargetsFromFile("/nonexistent/file.txt")
+		Expect(err).To(HaveOccurred())
+		Expect(err.Error()).To(ContainSubstring("failed to open target file"))
+	})
+
+	It("returns error for invalid target format", func() {
+		filePath := filepath.Join(tempDir, "targets.txt")
+		content := "invalid-format\n"
+		err := os.WriteFile(filePath, []byte(content), 0600)
+		Expect(err).ToNot(HaveOccurred())
+
+		_, err = readTargetsFromFile(filePath)
+		Expect(err).To(HaveOccurred())
+	})
+
+	It("handles mixed valid and empty lines", func() {
+		filePath := filepath.Join(tempDir, "targets.txt")
+		content := "\n1:Music/Rock\n\n\n2:Music/Jazz\n\n"
+		err := os.WriteFile(filePath, []byte(content), 0600)
+		Expect(err).ToNot(HaveOccurred())
+
+		targets, err := readTargetsFromFile(filePath)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(targets).To(HaveLen(2))
+	})
+})