fix(serializer): handling of multi-part file extensions in SingleFile…

…Extension (#710)

Co-authored-by: tolga.eren <tolga.eren@adevinta.com>
Co-authored-by: noahnu <noahnu@gmail.com>

src/syrupy/extensions/single_file.py

@@ -80,8 +80,11 @@ def dirname(cls, *, test_location: "PyTestLocation") -> str:
     def _read_snapshot_collection(
         self, *, snapshot_location: str
     ) -> "SnapshotCollection":
+        file_ext_len = len(self._file_extension) + 1 if self._file_extension else 0
+        filename_wo_ext = snapshot_location[:-file_ext_len]
+
         snapshot_collection = SnapshotCollection(location=snapshot_location)
-        snapshot_collection.add(Snapshot(name=Path(snapshot_location).stem))
+        snapshot_collection.add(Snapshot(name=Path(filename_wo_ext).stem))
         return snapshot_collection
 
     def _read_snapshot_data_from_location(

tests/integration/test_single_file_multiple_extensions.py

@@ -0,0 +1,40 @@
+from pathlib import Path
+
+
+def test_multiple_file_extensions(testdir):
+    file_extension = "ext2.ext1"
+
+    testcase = f"""
+    import pytest
+    from syrupy.extensions.single_file import SingleFileSnapshotExtension
+
+    class DotInFileExtension(SingleFileSnapshotExtension):
+        _file_extension = "{file_extension}"
+
+    @pytest.fixture
+    def snapshot(snapshot):
+        return snapshot.use_extension(DotInFileExtension)
+
+    def test_dot_in_filename(snapshot):
+        assert b"expected_data" == snapshot
+    """
+
+    test_file: Path = testdir.makepyfile(test_file=testcase)
+
+    result = testdir.runpytest("-v", "--snapshot-update")
+    result.stdout.re_match_lines((r"1 snapshot generated\."))
+    assert "snapshots unused" not in result.stdout.str()
+    assert result.ret == 0
+
+    snapshot_file = (
+        Path(test_file).parent
+        / "__snapshots__"
+        / "test_file"
+        / f"test_dot_in_filename.{file_extension}"
+    )
+    assert snapshot_file.exists()
+
+    result = testdir.runpytest("-v")
+    result.stdout.re_match_lines((r"1 snapshot passed\."))
+    assert "snapshots unused" not in result.stdout.str()
+    assert result.ret == 0