Add create_new method

src/components/flac_tag.rs

@@ -170,7 +170,7 @@ impl AudioTagEdit for FlacTag {
         self.remove("ALBUMARTIST");
     }
 
-    fn album_cover(&self) -> Option<Picture> {
+    fn album_cover(&self) -> Option<Picture<'_>> {
         self.inner
             .pictures()
             .find(|&pic| matches!(pic.picture_type, metaflac::block::PictureType::CoverFront))

src/components/id3_tag.rs

@@ -150,7 +150,7 @@ impl AudioTagEdit for Id3v2Tag {
         self.inner.remove_album_artist();
     }
 
-    fn album_cover(&self) -> Option<Picture> {
+    fn album_cover(&self) -> Option<Picture<'_>> {
         self.inner
             .pictures()
             .find(|&pic| matches!(pic.picture_type, id3::frame::PictureType::CoverFront))

src/components/mp4_tag.rs

@@ -205,7 +205,7 @@ impl AudioTagEdit for Mp4Tag {
         self.inner.add_album_artist(v);
     }
 
-    fn album_cover(&self) -> Option<Picture> {
+    fn album_cover(&self) -> Option<Picture<'_>> {
         self.inner.artwork().and_then(|data| match data.fmt {
             ImgFmt::Jpeg => Some(Picture {
                 data: data.data,

src/lib.rs

@@ -136,19 +136,46 @@ impl Tag {
             config,
         }
     }
+
+    /// Creates a brand new empty tag without reading from an existing file path.
+    pub fn empty(tag_type: TagType, config: Config) -> Box<dyn AudioTag + Send + Sync> {
+        match tag_type {
+            TagType::Id3v2 => Box::new({
+                let mut t = Id3v2Tag::new();
+                t.set_config(config);
+                t
+            }),
+            TagType::Mp4 => Box::new({
+                let mut t = Mp4Tag::new();
+                t.set_config(config);
+                t
+            }),
+            TagType::Flac => Box::new({
+                let mut t = FlacTag::new();
+                t.set_config(config);
+                t
+            }),
+        }
+    }
+
     pub fn read_from_path(
         &self,
         path: impl AsRef<Path>,
     ) -> crate::Result<Box<dyn AudioTag + Send + Sync>> {
-        match self.tag_type.unwrap_or(TagType::try_from_ext(
-            path.as_ref()
-                .extension()
-                .ok_or(Error::UnknownFileExtension(String::new()))?
-                .to_string_lossy()
-                .to_string()
-                .to_lowercase()
-                .as_str(),
-        )?) {
+        let tag_type = match self.tag_type {
+            Some(tag_type) => tag_type,
+            None => TagType::try_from_ext(
+                path.as_ref()
+                    .extension()
+                    .ok_or(Error::UnknownFileExtension(String::new()))?
+                    .to_string_lossy()
+                    .to_string()
+                    .to_lowercase()
+                    .as_str(),
+            )?,
+        };
+
+        match tag_type {
             TagType::Id3v2 => Ok(Box::new({
                 let mut t = Id3v2Tag::read_from_path(path)?;
                 t.set_config(self.config);

src/traits.rs

@@ -88,7 +88,7 @@ pub trait AudioTagEdit: AudioTagConfig {
         self.set_album_artist(artist);
     }
 
-    fn album_cover(&self) -> Option<Picture>;
+    fn album_cover(&self) -> Option<Picture<'_>>;
     fn set_album_cover(&mut self, cover: Picture);
     fn remove_album_cover(&mut self);
 

tests/io.rs

@@ -86,3 +86,16 @@ macro_rules! test_file {
 test_file!(test_mp3, "assets/a.mp3");
 test_file!(test_m4a, "assets/a.m4a");
 test_file!(test_flac, "assets/a.flac");
+
+#[test]
+fn test_read_from_path_honours_tag_type() {
+    let tmp = Builder::new().suffix(".xyz").tempfile().unwrap();
+    fs::copy("assets/a.mp3", &tmp).unwrap();
+
+    let tag = Tag::default()
+        .with_tag_type(audiotags::TagType::Id3v2)
+        .read_from_path(tmp.path())
+        .expect("should use explicit tag type, not file extension");
+
+    assert_eq!(tag.date().unwrap().year, 2013);
+}