test: fixed some things to make mutmut work

src/inline_snapshot/pytest_plugin.py

@@ -4,6 +4,7 @@
 from pathlib import Path
 
 import pytest
+from inline_snapshot.testing._example import init_env
 from rich import box
 from rich.console import Console
 from rich.panel import Panel
@@ -54,6 +55,8 @@ def xdist_running(config):
 def pytest_configure(config):
     global flags
 
+    init_env()
+
     _config.config = _config.read_config(config.rootpath / "pyproject.toml")
 
     if config.option.inline_snapshot is None:

src/inline_snapshot/testing/_example.py

@@ -22,6 +22,17 @@
 from .._types import Snapshot
 
 
+def init_env():
+    import inline_snapshot._inline_snapshot as inline_snapshot
+
+    inline_snapshot.snapshots = {}
+    inline_snapshot._update_flags = inline_snapshot.Flags()
+    inline_snapshot._active = True
+    external.storage = None
+    inline_snapshot._files_with_snapshots = set()
+    inline_snapshot._missing_values = 0
+
+
 @contextlib.contextmanager
 def snapshot_env():
     import inline_snapshot._inline_snapshot as inline_snapshot