refactor: make write_snapshot a classmethod

src/syrupy/extensions/amber/__init__.py

@@ -61,8 +61,9 @@ def _read_snapshot_data_from_location(
         snapshot = snapshots.get(snapshot_name)
         return snapshot.data if snapshot else None
 
+    @classmethod
     def _write_snapshot_collection(
-        self, *, snapshot_collection: "SnapshotCollection"
+        cls, *, snapshot_collection: "SnapshotCollection"
     ) -> None:
         DataSerializer.write_file(snapshot_collection, merge=True)
 

src/syrupy/extensions/base.py

@@ -96,14 +96,15 @@ def get_snapshot_name(
             index_suffix = f".{index}"
         return f"{test_location.snapshot_name}{index_suffix}"
 
+    @classmethod
     def get_location(
-        self, *, test_location: "PyTestLocation", index: "SnapshotIndex"
+        cls, *, test_location: "PyTestLocation", index: "SnapshotIndex"
     ) -> str:
-        """Returns full location where snapshot data is stored."""
-        basename = self._get_file_basename(test_location=test_location, index=index)
-        fileext = f".{self._file_extension}" if self._file_extension else ""
+        """Returns full filepath where snapshot data is stored."""
+        basename = cls._get_file_basename(test_location=test_location, index=index)
+        fileext = f".{cls._file_extension}" if cls._file_extension else ""
         return str(
-            Path(self.dirname(test_location=test_location)).joinpath(
+            Path(cls.dirname(test_location=test_location)).joinpath(
                 f"{basename}{fileext}"
             )
         )
@@ -155,8 +156,9 @@ def read_snapshot(
             raise SnapshotDoesNotExist()
         return snapshot_data
 
+    @classmethod
     def write_snapshot(
-        self,
+        cls,
         *,
         test_location: "PyTestLocation",
         snapshots: List[Tuple["SerializedData", "SnapshotIndex"]],
@@ -170,13 +172,19 @@ def write_snapshot(
         # Amber extension.
         locations: DefaultDict[str, List["Snapshot"]] = defaultdict(list)
         for data, index in snapshots:
-            location = self.get_location(test_location=test_location, index=index)
-            snapshot_name = self.get_snapshot_name(
+            location = cls.get_location(test_location=test_location, index=index)
+            snapshot_name = cls.get_snapshot_name(
                 test_location=test_location, index=index
             )
             locations[location].append(Snapshot(name=snapshot_name, data=data))
 
-            self.__ensure_snapshot_dir(test_location=test_location, index=index)
+            # Ensures the folder path for the snapshot file exists.
+            try:
+                Path(
+                    cls.get_location(test_location=test_location, index=index)
+                ).parent.mkdir(parents=True)
+            except FileExistsError:
+                pass
 
         for location, location_snapshots in locations.items():
             snapshot_collection = SnapshotCollection(location=location)
@@ -208,7 +216,7 @@ def write_snapshot(
                     )
                     warnings.warn(warning_msg)
 
-            self._write_snapshot_collection(snapshot_collection=snapshot_collection)
+            cls._write_snapshot_collection(snapshot_collection=snapshot_collection)
 
     @abstractmethod
     def delete_snapshots(
@@ -238,38 +246,28 @@ def _read_snapshot_data_from_location(
         """
         raise NotImplementedError
 
+    @classmethod
     @abstractmethod
     def _write_snapshot_collection(
-        self, *, snapshot_collection: "SnapshotCollection"
+        cls, *, snapshot_collection: "SnapshotCollection"
     ) -> None:
         """
         Adds the snapshot data to the snapshots in collection location
         """
         raise NotImplementedError
 
-    def dirname(self, *, test_location: "PyTestLocation") -> str:
+    @classmethod
+    def dirname(cls, *, test_location: "PyTestLocation") -> str:
         test_dir = Path(test_location.filepath).parent
         return str(test_dir.joinpath(SNAPSHOT_DIRNAME))
 
+    @classmethod
     def _get_file_basename(
-        self, *, test_location: "PyTestLocation", index: "SnapshotIndex"
+        cls, *, test_location: "PyTestLocation", index: "SnapshotIndex"
     ) -> str:
         """Returns file basename without extension. Used to create full filepath."""
         return test_location.basename
 
-    def __ensure_snapshot_dir(
-        self, *, test_location: "PyTestLocation", index: "SnapshotIndex"
-    ) -> None:
-        """
-        Ensures the folder path for the snapshot file exists.
-        """
-        try:
-            Path(
-                self.get_location(test_location=test_location, index=index)
-            ).parent.mkdir(parents=True)
-        except FileExistsError:
-            pass
-
 
 class SnapshotReporter(ABC):
     _context_line_count = 1

src/syrupy/extensions/single_file.py

@@ -49,7 +49,7 @@ def serialize(
         exclude: Optional["PropertyFilter"] = None,
         matcher: Optional["PropertyMatcher"] = None,
     ) -> "SerializedData":
-        return self._supported_dataclass(data)
+        return self.get_supported_dataclass()(data)
 
     @classmethod
     def get_snapshot_name(
@@ -66,15 +66,15 @@ def delete_snapshots(
     ) -> None:
         Path(snapshot_location).unlink()
 
+    @classmethod
     def _get_file_basename(
-        self, *, test_location: "PyTestLocation", index: "SnapshotIndex"
+        cls, *, test_location: "PyTestLocation", index: "SnapshotIndex"
     ) -> str:
-        return self.get_snapshot_name(test_location=test_location, index=index)
+        return cls.get_snapshot_name(test_location=test_location, index=index)
 
-    def dirname(self, *, test_location: "PyTestLocation") -> str:
-        original_dirname = super(SingleFileSnapshotExtension, self).dirname(
-            test_location=test_location
-        )
+    @classmethod
+    def dirname(cls, *, test_location: "PyTestLocation") -> str:
+        original_dirname = AbstractSyrupyExtension.dirname(test_location=test_location)
         return str(Path(original_dirname).joinpath(test_location.basename))
 
     def _read_snapshot_collection(
@@ -89,41 +89,46 @@ def _read_snapshot_data_from_location(
     ) -> Optional["SerializableData"]:
         try:
             with open(
-                snapshot_location, f"r{self._write_mode}", encoding=self._write_encoding
+                snapshot_location,
+                f"r{self._write_mode}",
+                encoding=self.get_write_encoding(),
             ) as f:
                 return f.read()
         except FileNotFoundError:
             return None
 
-    @property
-    def _supported_dataclass(self) -> Union[Type[str], Type[bytes]]:
-        if self._write_mode == WriteMode.TEXT:
+    @classmethod
+    def get_supported_dataclass(cls) -> Union[Type[str], Type[bytes]]:
+        if cls._write_mode == WriteMode.TEXT:
             return str
         return bytes
 
-    @property
-    def _write_encoding(self) -> Optional[str]:
-        if self._write_mode == WriteMode.TEXT:
+    @classmethod
+    def get_write_encoding(cls) -> Optional[str]:
+        if cls._write_mode == WriteMode.TEXT:
             return TEXT_ENCODING
         return None
 
+    @classmethod
     def _write_snapshot_collection(
-        self, *, snapshot_collection: "SnapshotCollection"
+        cls, *, snapshot_collection: "SnapshotCollection"
     ) -> None:
         filepath, data = (
             snapshot_collection.location,
             next(iter(snapshot_collection)).data,
         )
-        if not isinstance(data, self._supported_dataclass):
+        if not isinstance(data, cls.get_supported_dataclass()):
             error_text = gettext(
                 "Can't write non supported data. Expected '{}', got '{}'"
             )
             raise TypeError(
                 error_text.format(
-                    self._supported_dataclass.__name__, type(data).__name__
+                    cls.get_supported_dataclass().__name__, type(data).__name__
                 )
             )
-        with open(filepath, f"w{self._write_mode}", encoding=self._write_encoding) as f:
+        with open(
+            filepath, f"w{cls._write_mode}", encoding=cls.get_write_encoding()
+        ) as f:
             f.write(data)
 
     @classmethod

tests/examples/test_custom_snapshot_directory.py

@@ -21,7 +21,8 @@
 
 
 class DifferentDirectoryExtension(AmberSnapshotExtension):
-    def dirname(self, *, test_location: "PyTestLocation") -> str:
+    @classmethod
+    def dirname(cls, *, test_location: "PyTestLocation") -> str:
         return str(Path(test_location.filepath).parent.joinpath(DIFFERENT_DIRECTORY))
 
 

tests/examples/test_custom_snapshot_directory_2.py

@@ -20,7 +20,8 @@
 
 def create_versioned_fixture(version: int):
     class VersionedJSONExtension(JSONSnapshotExtension):
-        def dirname(self, *, test_location: "PyTestLocation") -> str:
+        @classmethod
+        def dirname(cls, *, test_location: "PyTestLocation") -> str:
             return str(
                 Path(test_location.filepath).parent.joinpath(
                     "__snapshots__", f"v{version}"

tests/integration/test_snapshot_outside_directory.py

@@ -11,7 +11,8 @@ def testcases(testdir, tmp_path):
         from syrupy.extensions.amber import AmberSnapshotExtension
 
         class CustomSnapshotExtension(AmberSnapshotExtension):
-            def dirname(self, *, test_location):
+            @classmethod
+            def dirname(cls, *, test_location):
                 return {str(dirname)!r}
 
         @pytest.fixture

tests/integration/test_snapshot_use_extension.py

@@ -26,7 +26,8 @@ def get_snapshot_name(cls, *, test_location, index):
                 testname = test_location.testname[::-1]
                 return f"{testname}.{index}"
 
-            def _get_file_basename(self, *, test_location, index):
+            @classmethod
+            def _get_file_basename(cls, *, test_location, index):
                 return test_location.basename[::-1]
 
         @pytest.fixture