Added tests and did improved class and file structure.

smalltag/_formats/_id3.py

@@ -1,19 +1,18 @@
 #!/usr/bin/python3
 
+from __future__ import annotations
 from struct import pack
-from tinytag import TinyTag
+from io import BytesIO
+from tinytag import TinyTag, tinytag
 
 from .. import SmallTag
 
-if True:
+if False:
     from collections.abc import Callable, Iterator  # noqa
     from typing import Any, BinaryIO, Dict, List
 
 
-_tinytag_id3 = TinyTag._get_parser_for_filename(".mp3")  # noqa
-
-
-class _ID3(SmallTag, _tinytag_id3):
+class _ID3(SmallTag, tinytag._ID3):
     @staticmethod
     def _synchsafe(unsynchsafe_int: int) -> tuple[int, ...]:
         ints = (
@@ -41,7 +40,6 @@ class _ID3(SmallTag, _tinytag_id3):
         new_header = self._compose_id3v2_header(size)
 
         new_tag = new_header + new_frames
-        print(new_tag)
 
         size, extended, major = self._parse_id3v2_header(self._filehandler)
 

smalltag/smalltag.py

@@ -1,15 +1,29 @@
 #!/usr/bin/python3
 
 from __future__ import annotations
-from tinytag import TinyTag, UnsupportedFormatError
+from tinytag import tinytag
 
 
 if False:  # just stole this lazy import type hinting trick from tinytag
     from collections.abc import Callable, Iterator  # noqa
     from typing import Any, BinaryIO, Dict, List
 
+TinyTag = tinytag.TinyTag
+UnsupportedFormatError = tinytag.UnsupportedFormatError
+
 
 class SmallTag(TinyTag):
+    _file_extension_mapping: dict[tuple[str, ...], type[SmallTag]]= {
+        (".mp1", ".mp2", ".mp3"): None,
+        ('.oga', '.ogg', '.opus', '.spx'): tinytag._Ogg,
+        ('.wav',): tinytag._Wave,
+        ('.flac',): tinytag._Flac,
+        ('.wma',): tinytag._Wma,
+        ('.m4b', '.m4a', '.m4r', '.m4v', '.mp4',
+         '.aax', '.aaxc'): tinytag._MP4,
+        ('.aiff', '.aifc', '.aif', '.afc'): tinytag._Aiff,
+    }
+
     @classmethod
     def _get_parser_class(
             cls,
@@ -30,6 +44,37 @@ class SmallTag(TinyTag):
         raise UnsupportedFormatError(
             'No tag reader found to support file type')
 
+    @classmethod
+    def _get_parser_for_file_handle(
+            cls,
+            filehandle: BinaryIO
+    ) -> type[SmallTag] | None:
+        # https://en.wikipedia.org/wiki/List_of_file_signatures
+        header = filehandle.read(35)
+        filehandle.seek(0)
+        if header.startswith(b'ID3') or header.startswith(b'\xff\xfb'):
+            return _ID3
+
+        super()._get_parser_for_file_handle(filehandle)
+        # if header.startswith(b'fLaC'):
+        #     return _Flac
+        # if ((header[4:8] == b'ftyp'
+        #      and header[8:11] in {b'M4A', b'M4B', b'aax'})
+        #         or b'\xff\xf1' in header):
+        #     return _MP4
+        # if (header.startswith(b'OggS')
+        #         and (header[29:33] == b'FLAC' or header[29:35] == b'vorbis'
+        #              or header[28:32] == b'Opus' or header[29:34] == b'Speex')):
+        #     return _Ogg
+        # if header.startswith(b'RIFF') and header[8:12] == b'WAVE':
+        #     return _Wave
+        # if header.startswith(b'\x30\x26\xB2\x75\x8E\x66\xCF\x11\xA6\xD9\x00'
+        #                      b'\xAA\x00\x62\xCE\x6C'):
+        #     return _Wma
+        # if header.startswith(b'FORM') and header[8:12] in {b'AIFF', b'AIFC'}:
+        #     return _Aiff
+        # return None
+
     def write(self, file_obj: BinaryIO = None):
         raise NotImplementedError
 
@@ -42,14 +87,14 @@ class SmallTag(TinyTag):
                 "(Has to be from the same file as specified while creating this TinyTag instance.)"
             )
 
-        if file_obj is not None and not self._filehandler.closed():
+        if file_obj is not None and not self._filehandler.closed:
             self._filehandler.close()
 
-        if file_obj is not None:
-            self._filehandler = file_obj
+        if file_obj is None:
+            self._filehandler = open(self.filename, "rb+")
 
         else:
-            self._filehandler = open(self.filename, "rb+")
+            self._filehandler = file_obj
 
         return should_close_file
 
@@ -58,13 +103,5 @@ class SmallTag(TinyTag):
 # (this solution is stupid, but I don't know anything better.)
 from ._formats import _ID3  # noqa
 
-SmallTag._file_extension_mapping = {
-        ('.mp1', '.mp2', '.mp3'): _ID3,
-        # ('.oga', '.ogg', '.opus', '.spx'): _Ogg,  (Not yet implemented.)
-        # ('.wav',): _Wave,
-        # ('.flac',): _Flac,
-        # ('.wma',): _Wma,
-        # ('.m4b', '.m4a', '.m4r', '.m4v', '.mp4',
-        #  '.aax', '.aaxc'): _MP4,
-        # ('.aiff', '.aifc', '.aif', '.afc'): _Aiff,
-}
+SmallTag._file_extension_mapping[(".mp1", ".mp2", ".mp3")] = _ID3
+

tests/formats/test_id3.py

@@ -0,0 +1,30 @@
+#!/usr/bin/python3
+
+from smalltag import SmallTag
+
+
+# chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-_ "
+
+# no "b" because there is a bug in TinyTag 2.1.0 that removes "b"s if they are at the beginning of a string
+chars = "acdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789- _"
+
+
+def test_writing_text_frames():
+    for char1 in chars:
+        for char2 in chars:
+            field_content = f"{char1}{char2}Test{char2}{char1}"
+
+            tag = SmallTag.get("formats/test.mp3")
+
+            tag.title = field_content
+            tag.artist = field_content
+            tag.album = field_content
+
+            tag.write()
+
+            tag = SmallTag.get("formats/test.mp3")
+
+            assert tag.title == field_content
+            assert tag.artist == field_content
+            assert tag.album == field_content
+

tests/id3.py

@@ -1,17 +0,0 @@
-#!/usr/bin/python3
-
-from json import dumps
-from smalltag import SmallTag
-
-
-test_tag = SmallTag.get("test.mp3")
-print(test_tag)
-
-print(test_tag.title)
-test_tag.title = "bTest"
-
-test_tag.write()
-
-test_tag = SmallTag.get("test.mp3")
-
-print(dumps(test_tag.as_dict(), indent="  "))