feat: remove unused snapshots in snapshot file

src/syrupy/assertion.py

@@ -1,12 +1,12 @@
 import traceback
 import pytest
 import os
-from typing import Callable, List, Optional, Any
+from typing import Any, Callable, List, Optional, Type
 
 from .exceptions import SnapshotDoesNotExist
 
-from .io import SnapshotIO, SnapshotIOClass
-from .serializer import SnapshotSerializer, SnapshotSerializerClass
+from .io import SnapshotIO
+from .serializer import SnapshotSerializer
 from .location import TestLocation
 
 
@@ -15,8 +15,8 @@ def __init__(
         self,
         *,
         update_snapshots: bool,
-        io_class: SnapshotIOClass,
-        serializer_class: SnapshotSerializerClass,
+        io_class: Type[SnapshotIO],
+        serializer_class: Type[SnapshotSerializer],
         test_location: TestLocation,
         session,
     ):
@@ -51,8 +51,8 @@ def num_executions(self) -> int:
 
     def with_class(
         self,
-        io_class: SnapshotIOClass = None,
-        serializer_class: SnapshotSerializerClass = None,
+        io_class: Type[SnapshotIO] = None,
+        serializer_class: Type[SnapshotSerializer] = None,
     ):
         return self.__class__(
             update_snapshots=self._update_snapshots,

src/syrupy/io.py

@@ -167,6 +167,3 @@ def _snap_file_hook(self, index: int):
         snapshot_file = self.get_filepath(index)
         snapshot_name = self.get_snapshot_name(index)
         self._file_hook(snapshot_file, snapshot_name)
-
-
-SnapshotIOClass = Callable[..., SnapshotIO]

src/syrupy/plugins/image/io.py

@@ -19,9 +19,9 @@ def discover_snapshots(self, filepath: str) -> Set[str]:
         return {os.path.splitext(os.path.basename(filepath))[0]}
 
     def get_file_basename(self, index: int) -> str:
-        ext = f".{self.extension}"
+        maybe_extension = f".{self.extension}" if self.extension else ""
         sanitized_name = self._clean_filename(self.get_snapshot_name(index=index))
-        return f"{sanitized_name[:255 - len(ext)]}{ext}"
+        return f"{sanitized_name}{maybe_extension}"
 
     def _get_snapshot_dirname(self):
         return os.path.splitext(os.path.basename(str(self.test_location.filename)))[0]
@@ -48,4 +48,5 @@ def _write_file(self, filepath: str, data: Any):
 
     def _clean_filename(self, filename: str) -> str:
         filename = str(filename).strip().replace(" ", "_")
-        return re.sub(r"(?u)[^-\w.]", "", filename)
+        max_filename_length = 255 - (len(self.extension) if self.extension else 0)
+        return re.sub(r"(?u)[^-\w.]", "", filename)[:max_filename_length]

src/syrupy/serializer.py

@@ -10,6 +10,3 @@ def encode(self, data):
 
     def decode(self, data):
         return data
-
-
-SnapshotSerializerClass = Callable[..., SnapshotSerializer]

src/syrupy/session.py

@@ -156,7 +156,7 @@ def _diff_snapshot_files(
         }
 
     def _count_snapshots(self, snapshot_files: SnapshotFiles) -> int:
-        return sum([len(snapshots) for _, snapshots in snapshot_files.items()])
+        return sum(map(len, snapshot_files.values()))
 
     def _in_snapshot_dir(self, path: str) -> bool:
         parts = path.split(os.path.sep)