fix: updated Client.watch_snapshot to use proper dataclass as argument type

README.md

@@ -297,10 +297,10 @@ Client.schedule_snapshot_auto_update(
 
 ```python
 # Watch for snapshot file changes
-Client.watch_snapshot({
-    'success': lambda: print("✅ Snapshot loaded successfully"),
-    'reject': lambda e: print(f"❌ Error loading snapshot: {e}")
-})
+Client.watch_snapshot(WatchSnapshotCallback(
+    success=lambda: print("✅ Snapshot loaded successfully"),
+    reject=lambda e: print(f"❌ Error loading snapshot: {e}")
+))
 ```
 
 ## Testing & Development

switcher_client/__init__.py

@@ -1,9 +1,11 @@
 from .client import Client
 from .switcher import Switcher
 from .lib.globals.global_context import ContextOptions
+from .lib.snapshot_watcher import WatchSnapshotCallback
 
 __all__ = [
     'Client',
     'Switcher',
     'ContextOptions',
+    'WatchSnapshotCallback',
 ]

switcher_client/client.py

@@ -7,7 +7,7 @@
 from .lib.remote import Remote
 from .lib.snapshot_auto_updater import SnapshotAutoUpdater
 from .lib.snapshot_loader import check_switchers, load_domain, validate_snapshot, save_snapshot
-from .lib.snapshot_watcher import SnapshotWatcher
+from .lib.snapshot_watcher import SnapshotWatcher, WatchSnapshotCallback
 from .lib.utils.execution_logger import ExecutionLogger
 from .lib.utils.timed_match.timed_match import TimedMatch
 from .lib.utils import get
@@ -162,14 +162,13 @@ def terminate_snapshot_auto_update():
         Client._snapshot_auto_updater.terminate()
 
     @staticmethod
-    def watch_snapshot(callback: Optional[dict] = None) -> None:
+    def watch_snapshot(callback: Optional[WatchSnapshotCallback] = None) -> None:
         """ Watch snapshot file for changes and invoke callbacks on result """
-        callback = get(callback, {})
+        callback = get(callback, WatchSnapshotCallback())
         snapshot_location = Client._context.options.snapshot_location
 
         if snapshot_location is None:
-            reject = callback.get('reject', lambda _: None)
-            return reject(Exception("Snapshot location is not defined in the context options"))
+            return callback.reject(Exception("Snapshot location is not defined in the context options"))
 
         environment = get(Client._context.environment, DEFAULT_ENVIRONMENT)
         Client._snapshot_watcher.watch_snapshot(snapshot_location, environment, callback)

switcher_client/lib/snapshot_watcher.py

@@ -1,11 +1,20 @@
 import os
 import threading
 
+from dataclasses import dataclass, field
+from typing import Callable
+
 from .snapshot_loader import load_domain
 from .globals.global_snapshot import GlobalSnapshot
 
 _POLL_INTERVAL = 1  # seconds between file stat checks
 
+@dataclass
+class WatchSnapshotCallback:
+    """ Typed callback contract for Client.watch_snapshot """
+    success: Callable[[], None] = field(default_factory=lambda: (lambda: None))
+    reject: Callable[[Exception], None] = field(default_factory=lambda: (lambda _: None))
+
 class SnapshotWatcher:
     """ Watches the snapshot file for changes and updates the switcher accordingly """
 
@@ -14,7 +23,7 @@ def __init__(self):
         self._ready_event: threading.Event = threading.Event()
         self._thread: threading.Thread | None = None
 
-    def watch_snapshot(self, snapshot_location: str, environment: str, callback: dict) -> None:
+    def watch_snapshot(self, snapshot_location: str, environment: str, callback: WatchSnapshotCallback) -> None:
         """ Watch snapshot file for changes and invoke callbacks on result """
         self._stop_event.clear()
         self._ready_event.clear()
@@ -34,7 +43,7 @@ def unwatch_snapshot(self) -> None:
             self._thread.join(timeout=5.0)
             self._thread = None
 
-    def _watch(self, snapshot_location: str, environment: str, callback: dict) -> None:
+    def _watch(self, snapshot_location: str, environment: str, callback: WatchSnapshotCallback) -> None:
         snapshot_file = f"{snapshot_location}/{environment}.json"
         last_mtime = self._get_mtime(snapshot_file)
         self._ready_event.set()
@@ -49,13 +58,10 @@ def _watch(self, snapshot_location: str, environment: str, callback: dict) -> No
     def _get_mtime(self, snapshot_file: str) -> float:
         return os.stat(snapshot_file).st_mtime
 
-    def _on_modify_snapshot(self, snapshot_location: str, environment: str, callback: dict) -> None:
-        success = callback.get('success', lambda: None)
-        reject = callback.get('reject', lambda _: None)
-
+    def _on_modify_snapshot(self, snapshot_location: str, environment: str, callback: WatchSnapshotCallback) -> None:
         try:
             snapshot = load_domain(snapshot_location, environment)
             GlobalSnapshot.init(snapshot)
-            success()
+            callback.success()
         except Exception as error:
-            reject(error)
+            callback.reject(error)

tests/playground/index.py

@@ -4,7 +4,7 @@
 from util import monitor_run
 from switcher_client.lib.globals.global_context import DEFAULT_ENVIRONMENT
 from switcher_client.lib.globals.global_snapshot import LoadSnapshotOptions
-from switcher_client import Client, ContextOptions
+from switcher_client import Client, ContextOptions, WatchSnapshotCallback
 
 SWITCHER_KEY = 'CLIENT_PYTHON_FEATURE'
 LOOP = True
@@ -101,18 +101,18 @@ def uc_watch_snapshot():
     ))
 
     Client.load_snapshot()
-    Client.watch_snapshot({
-        'success': lambda: print("✅ Snapshot loaded successfully"),
-        'reject': lambda e: print(f"❌ Error loading snapshot: {e}")
-    })
+    Client.watch_snapshot(WatchSnapshotCallback(
+        success=lambda: print("✅ Snapshot loaded successfully"),
+        reject=lambda e: print(f"❌ Error loading snapshot: {e}")
+    ))
 
     switcher = Client.get_switcher('FF2FOR2030')
     monitor_thread = threading.Thread(target=monitor_run, args=(switcher,True), daemon=True)
     monitor_thread.start()
 
 try:
     # Replace with use case
-    uc_simple_api_call()
+    uc_watch_snapshot()
     while LOOP:
         time.sleep(1)
 except KeyboardInterrupt:

tests/test_client_watch_snapshot.py

@@ -6,7 +6,7 @@
 
 from switcher_client.client import Client, ContextOptions
 from switcher_client.lib.globals.global_context import DEFAULT_ENVIRONMENT
-from switcher_client.lib.snapshot_watcher import SnapshotWatcher
+from switcher_client.lib.snapshot_watcher import SnapshotWatcher, WatchSnapshotCallback
 
 class TestClientWatchSnapshot:
     """ Test suite for Client.watch_snapshot """
@@ -38,10 +38,10 @@ def test_watch_snapshot(self):
 
         # test
         switcher = Client.get_switcher('FF2FOR2030')
-        Client.watch_snapshot({
-            'success': lambda: setattr(self, 'async_success', True),
-            'reject': lambda err: setattr(self, 'async_error', err)
-        })
+        Client.watch_snapshot(WatchSnapshotCallback(
+            success=lambda: setattr(self, 'async_success', True),
+            reject=lambda err: setattr(self, 'async_error', err)
+        ))
 
         assert switcher.is_on()
         modify_fixture_snapshot(fixture_location, fixture_env, fixture_env_file_modified)
@@ -61,10 +61,10 @@ def test_watch_snapshot_err_no_snapshot_location(self):
         given_context()
 
         # test
-        Client.watch_snapshot({
-            'success': lambda: setattr(self, 'async_success', True),
-            'reject': lambda err: setattr(self, 'async_error', err)
-        })
+        Client.watch_snapshot(WatchSnapshotCallback(
+            success=lambda: setattr(self, 'async_success', True),
+            reject=lambda err: setattr(self, 'async_error', err)
+        ))
 
         # then
         assert self.async_success is None
@@ -83,10 +83,10 @@ def test_watch_snapshot_err_malformed_snapshot(self):
         Client.load_snapshot()
 
         # test
-        Client.watch_snapshot({
-            'success': lambda: setattr(self, 'async_success', True),
-            'reject': lambda err: setattr(self, 'async_error', err)
-        })
+        Client.watch_snapshot(WatchSnapshotCallback(
+            success=lambda: setattr(self, 'async_success', True),
+            reject=lambda err: setattr(self, 'async_error', err)
+        ))
 
         modify_fixture_snapshot(fixture_location, fixture_env, fixture_env_file_modified)