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...)
 		}
 	}