get file mime type done

fileinfo.go

@@ -1,7 +1,10 @@
 package main
 
 import (
+	"log"
 	"os"
+
+	"github.com/rakyll/magicmime"
 )
 
 func getFileSize(s string) (size int64, err error) {
@@ -19,6 +22,17 @@ func getFileSize(s string) (size int64, err error) {
 	return
 }
 
-func getFileMime(s string) (mime string) {
-	return ""
+func getFileMime(s string) (mimetype string, err error) {
+	if err := magicmime.Open(magicmime.MAGIC_MIME_TYPE | magicmime.MAGIC_SYMLINK | magicmime.MAGIC_ERROR); err != nil {
+		log.Fatal(err)
+		return "", err
+	}
+	defer magicmime.Close()
+
+	mimetype, err = magicmime.TypeByFile(s)
+	if err != nil {
+		log.Fatalf("error occured during type lookup: %v", err)
+	}
+	//log.Printf("mime-type: %v", mimetype)
+	return
 }

fileinfo_test.go

@@ -18,3 +18,16 @@ func TestGetFileSize(t *testing.T) {
 		AssertEqual(t, size, int64(v), msg)
 	}
 }
+
+func TestGetMimeType(t *testing.T) {
+	var fileMime = map[string]string{
+		"media_for_test/640x480.jpg":   "image/jpeg",
+		"media_for_test/3640x3480.jpg": "image/jpeg",
+		"media_for_test/video.mp4":     "video/mp4",
+	}
+	for k, v := range fileMime {
+		mime, _ := getFileMime(k)
+		msg := fmt.Sprintf("%s should be %s, not %s", k, v, mime)
+		AssertEqual(t, mime, v, msg)
+	}
+}