feat!: change mutation_detection and allow_reactive_boolean defaults

BREAKING CHANGE: an error is now raised if a reactive variable (not its value) is used in boolean comparisons
BREAKIGN CHANGE: mutation detection is now enabled by default

Author: iisakkirotko

solara/components/__init__.py

@@ -73,5 +73,4 @@
     logger = logging.getLogger("solara.components")
     logger.warning(f"Default container {main.default_container} not found in solara.components. Defaulting to Column.")
 
-# TODO: When Solara 2.0 releases Column should be replaced with Fragment
-reacton.core._default_container = _container or Column  # noqa: F405
+reacton.core._default_container = _container or Fragment  # noqa: F405

solara/settings.py

@@ -54,9 +54,8 @@ class Config:
 
 class MainSettings(BaseSettings):
     check_hooks: str = "warn"
-    allow_reactive_boolean: bool = True
-    # TODO: also change default_container in solara/components/__init__.py
-    default_container: Optional[str] = "Column"
+    allow_reactive_boolean: bool = False
+    default_container: Optional[str] = "Fragment"
 
     class Config:
         env_prefix = "solara_"

solara/toestand.py

@@ -31,6 +31,7 @@
 
 import solara
 import solara.settings
+import solara.server.settings
 from solara import _using_solara_server
 from solara.util import nullcontext
 
@@ -372,7 +373,9 @@ def __init__(self, default_value: S, key=None, equals: Callable[[Any, Any], bool
         self.default_value = default_value
         self._unwrap = unwrap
         self.equals = equals
-        self._mutation_detection = solara.settings.storage.mutation_detection
+        self._mutation_detection = solara.settings.storage.mutation_detection is True or (
+            solara.settings.storage.mutation_detection is None and not solara.server.settings.main.mode == "production"
+        )
         if self._mutation_detection:
             frame = _find_outside_solara_frame()
             if frame is not None:
@@ -469,9 +472,11 @@ def mutation_detection_storage(default_value: S, key=None, equals=None) -> Value
 
 
 def default_storage(default_value: S, key=None, equals=None) -> ValueBase[S]:
-    # in solara v2 we will also do this when mutation_detection is None
-    # and we do not run on production mode
-    if solara.settings.storage.mutation_detection is True:
+    # We use mutation detection if it is explicitly enabled, or if it is not explicitly disabled and
+    # We aren't running in production mode
+    if solara.settings.storage.mutation_detection is True or (
+        solara.settings.storage.mutation_detection is None and not solara.server.settings.main.mode == "production"
+    ):
         return mutation_detection_storage(default_value, key=key, equals=equals)
     else:
         return KernelStoreValue[S](default_value, key=key, equals=equals or equals_extra)

tests/unit/toestand_test.py

@@ -852,13 +852,13 @@ def Test():
 
     box, rc = solara.render(Test(), handle_error=False)
 
-    if solara.settings.storage.mutation_detection:
+    if solara.settings.storage.mutation_detection is not False:
         # a copy is made, so get a reference to the actual used object
         df = get_storage(store).value.public
     assert rc.find(v.Alert).widget.children[0] == repr(id(df))
     df2 = df2.copy()
     store.set(df2)
-    if solara.settings.storage.mutation_detection:
+    if solara.settings.storage.mutation_detection is not False:
         df2 = get_storage(store).value.public
     assert rc.find(v.Alert).widget.children[0] == repr(id(df2))