Add "inspect" command to CLI

scanner/metadata/metadata.go

@@ -58,25 +58,35 @@ func Extract(files ...string) (map[string]Tags, error) {
 
 func NewTag(filePath string, fileInfo os.FileInfo, tags ParsedTags) Tags {
 	for t, values := range tags {
-		tags[t] = removeDuplicates(values)
+		values = removeDuplicatesAndEmpty(values)
+		if len(values) == 0 {
+			delete(tags, t)
+			continue
+		}
+		tags[t] = values
 	}
 	return Tags{
 		filePath: filePath,
 		fileInfo: fileInfo,
-		tags:     tags,
+		Tags:     tags,
 	}
 }
 
-func removeDuplicates(values []string) []string {
+func removeDuplicatesAndEmpty(values []string) []string {
 	encountered := map[string]struct{}{}
+	empty := true
 	var result []string
 	for _, v := range values {
 		if _, ok := encountered[v]; ok {
 			continue
 		}
 		encountered[v] = struct{}{}
+		empty = empty && v == ""
 		result = append(result, v)
 	}
+	if empty {
+		return nil
+	}
 	return result
 }
 
@@ -100,7 +110,7 @@ func (p ParsedTags) Map(customMappings ParsedTags) ParsedTags {
 type Tags struct {
 	filePath string
 	fileInfo os.FileInfo
-	tags     ParsedTags
+	Tags     ParsedTags
 }
 
 // Common tags
@@ -207,7 +217,7 @@ func (t Tags) getPeakValue(tagName string) float64 {
 
 func (t Tags) getTags(tagNames ...string) []string {
 	for _, tag := range tagNames {
-		if v, ok := t.tags[tag]; ok {
+		if v, ok := t.Tags[tag]; ok {
 			return v
 		}
 	}
@@ -225,7 +235,7 @@ func (t Tags) getFirstTagValue(tagNames ...string) string {
 func (t Tags) getAllTagValues(tagNames ...string) []string {
 	var values []string
 	for _, tag := range tagNames {
-		if v, ok := t.tags[tag]; ok {
+		if v, ok := t.Tags[tag]; ok {
 			values = append(values, v...)
 		}
 	}

scanner/metadata/metadata_internal_test.go

@@ -9,7 +9,7 @@ var _ = Describe("Tags", func() {
 	DescribeTable("getDate",
 		func(tag string, expectedYear int, expectedDate string) {
 			md := &Tags{}
-			md.tags = map[string][]string{"date": {tag}}
+			md.Tags = map[string][]string{"date": {tag}}
 			testYear, testDate := md.Date()
 			Expect(testYear).To(Equal(expectedYear))
 			Expect(testDate).To(Equal(expectedDate))
@@ -29,7 +29,7 @@ var _ = Describe("Tags", func() {
 	Describe("getMbzID", func() {
 		It("return a valid MBID", func() {
 			md := &Tags{}
-			md.tags = map[string][]string{
+			md.Tags = map[string][]string{
 				"musicbrainz_trackid":        {"8f84da07-09a0-477b-b216-cc982dabcde1"},
 				"musicbrainz_releasetrackid": {"6caf16d3-0b20-3fe6-8020-52e31831bc11"},
 				"musicbrainz_albumid":        {"f68c985d-f18b-4f4a-b7f0-87837cf3fbf9"},
@@ -44,7 +44,7 @@ var _ = Describe("Tags", func() {
 		})
 		It("return empty string for invalid MBID", func() {
 			md := &Tags{}
-			md.tags = map[string][]string{
+			md.Tags = map[string][]string{
 				"musicbrainz_trackid":       {"11406732-6"},
 				"musicbrainz_albumid":       {"11406732"},
 				"musicbrainz_artistid":      {"200455"},
@@ -60,7 +60,7 @@ var _ = Describe("Tags", func() {
 	Describe("getAllTagValues", func() {
 		It("returns values from all tag names", func() {
 			md := &Tags{}
-			md.tags = map[string][]string{
+			md.Tags = map[string][]string{
 				"genre": {"Rock", "Pop", "New Wave"},
 			}
 
@@ -68,23 +68,31 @@ var _ = Describe("Tags", func() {
 		})
 	})
 
-	Describe("removeDuplicates", func() {
+	Describe("removeDuplicatesAndEmpty", func() {
 		It("removes duplicates", func() {
 			md := NewTag("/music/artist/album01/Song.mp3", nil, ParsedTags{
 				"genre": []string{"pop", "rock", "pop"},
 				"date":  []string{"2023-03-01", "2023-03-01"},
 				"mood":  []string{"happy", "sad"},
 			})
-			Expect(md.tags).To(HaveKeyWithValue("genre", []string{"pop", "rock"}))
-			Expect(md.tags).To(HaveKeyWithValue("date", []string{"2023-03-01"}))
-			Expect(md.tags).To(HaveKeyWithValue("mood", []string{"happy", "sad"}))
+			Expect(md.Tags).To(HaveKeyWithValue("genre", []string{"pop", "rock"}))
+			Expect(md.Tags).To(HaveKeyWithValue("date", []string{"2023-03-01"}))
+			Expect(md.Tags).To(HaveKeyWithValue("mood", []string{"happy", "sad"}))
+		})
+		It("removes empty tags", func() {
+			md := NewTag("/music/artist/album01/Song.mp3", nil, ParsedTags{
+				"genre": []string{"pop", "rock", "pop"},
+				"mood":  []string{"", ""},
+			})
+			Expect(md.Tags).To(HaveKeyWithValue("genre", []string{"pop", "rock"}))
+			Expect(md.Tags).ToNot(HaveKey("mood"))
 		})
 	})
 
 	Describe("Bpm", func() {
 		var t *Tags
 		BeforeEach(func() {
-			t = &Tags{tags: map[string][]string{
+			t = &Tags{Tags: map[string][]string{
 				"fbpm": []string{"141.7"},
 			}}
 		})