Testing and minor improvements

README.md

@@ -23,20 +23,35 @@ func main() {
         panic(err)
     }
 
+    // extract ID3v1.1 tags 
     mp3tags, err := GetID3v11Tags(mp3file)
     if err != nil {
        panic(err)
     }
 
-    // printing all tags
+    // print all tags
     fmt.Printf("%+v",mp3tags)
 
-    // getting certain tag
+    // get a certain tag from "getter" function
     songname := mp3tags.GetSongName()
     
+    // get a certain tag from struct field
+    genre := mp3tags.Genre
+
     // etc.
 }
 ```
 
+# Testing
+
+```
+go test
+```
+or
+```
+go test -v
+```
+to get a verbose output
+
 # Under construction !
-## Bugs are a possibility rn in this state
+## Bugs are a possibility rn in this state, the package is still not tested properly 

id3v10.go

@@ -35,7 +35,7 @@ func GetID3v1Tags(rs io.ReadSeeker) (*ID3v1Tags, error) {
 
 	if !bytes.Equal(tag, []byte("TAG")) {
 		// no TAG, given file does not use ID3v1
-		return nil, fmt.Errorf("does not use ID3v1")
+		return nil, fmt.Errorf("does not use ID3v1: expected %s; got %s", "TAG", tag)
 	}
 
 	songname, err := readToString(rs, 30)

id3v10_test.go

@@ -0,0 +1,23 @@
+package id3ed
+
+import (
+	"os"
+	"testing"
+)
+
+func TestGetID3v1Tags(t *testing.T) {
+	testfile, err := os.Open("./testData/testmp3id3v1.mp3")
+	if err != nil {
+		t.Errorf("could not open file for testing: %s", err)
+	}
+	tags, err := GetID3v1Tags(testfile)
+	if err != nil {
+		t.Errorf("GetID3v1Tags failed: %s", err)
+	}
+
+	comment := tags.GetComment()
+
+	if comment != "Comment here " {
+		t.Errorf("GetID3v1Tags failed: expected %s; got %s", "Comment here ", comment)
+	}
+}

id3v11.go

@@ -32,7 +32,7 @@ func GetID3v11Tags(rs io.ReadSeeker) (*ID3v11Tags, error) {
 
 	if !bytes.Equal(tag, []byte("TAG")) {
 		// no TAG, given file does not use ID3v1
-		return nil, fmt.Errorf("does not use ID3v1")
+		return nil, fmt.Errorf("does not use ID3v1: expected %s; got %s", "TAG", tag)
 	}
 
 	songname, err := readToString(rs, 30)
@@ -50,11 +50,11 @@ func GetID3v11Tags(rs io.ReadSeeker) (*ID3v11Tags, error) {
 		return nil, err
 	}
 
-	yearBytes, err := read(rs, 4)
+	yearStr, err := readToString(rs, 4)
 	if err != nil {
 		return nil, err
 	}
-	year, err := strconv.Atoi(string(yearBytes))
+	year, err := strconv.Atoi(yearStr)
 	if err != nil {
 		return nil, fmt.Errorf("could not convert yearbytes into int: %s", err)
 	}

id3v11_test.go

@@ -0,0 +1,27 @@
+package id3ed
+
+import (
+	"fmt"
+	"os"
+	"testing"
+)
+
+func TestGetID3v11Tags(t *testing.T) {
+	testfile, err := os.Open("./testData/testmp3id3v1.mp3")
+	if err != nil {
+		t.Errorf("could not open file for testing: %s", err)
+	}
+	mp3tags, err := GetID3v11Tags(testfile)
+	if err != nil {
+		t.Errorf("GetID3v1Tags failed: %s", err)
+	}
+
+	if mp3tags.GetArtist() != "Artist" {
+		fmt.Printf("%v", mp3tags.Artist)
+		t.Errorf("GetID3v1Tags has failed:  expected %v; got %v", "Artist", mp3tags.GetArtist())
+	}
+
+	if mp3tags.GetTrack() != 8 {
+		t.Errorf("GetID3v1Tags has failed: expected %v; got %v", 8, mp3tags.GetTrack())
+	}
+}

id3v1_test.go

@@ -1,17 +0,0 @@
-package id3ed
-
-import (
-	"os"
-	"testing"
-)
-
-func TestGetID3v1Tags(t *testing.T) {
-	testfile, err := os.Open("./testData/id3v1.txt")
-	if err != nil {
-		t.Errorf("could not open file for testing: %s", err)
-	}
-	_, err = GetID3v1Tags(testfile)
-	if err != nil {
-		t.Errorf("GetID3v1Tags failed: %s", err)
-	}
-}

util.go

@@ -16,12 +16,22 @@ func read(rs io.Reader, n int) ([]byte, error) {
 	return read, nil
 }
 
-// Shortcut function to read n bytes and convert them into string
+// Shortcut function to read n bytes and convert them into string.
+// If encountered zero-byte - converts to string only previously read bytes
 func readToString(rs io.Reader, n int) (string, error) {
 	read := make([]byte, n)
 	_, err := rs.Read(read)
 	if err != nil {
 		return "", fmt.Errorf("could not read from reader: %s", err)
 	}
-	return string(read), nil
+
+	var readString string
+	for _, b := range read {
+		if b == 0 {
+			break
+		}
+		readString += string(b)
+	}
+
+	return readString, nil
 }