Convert validation loop config warnings to PossibleUserWarning

src/pytorch_lightning/CHANGELOG.md

@@ -9,6 +9,9 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/).
 
 ### Added
 
+-  Converted validation loop config warnings to `PossibleUserWarning` ([#13377](https://github.com/PyTorchLightning/pytorch-lightning/pull/13377))
+
+
 - Added a flag named `log_rank_zero_only` to `EarlyStopping` to disable logging to non-zero rank processes ([#13233](https://github.com/PyTorchLightning/pytorch-lightning/pull/13233))
 
 

src/pytorch_lightning/trainer/configuration_validator.py

@@ -19,6 +19,7 @@
 from pytorch_lightning.utilities.model_helpers import is_overridden
 from pytorch_lightning.utilities.rank_zero import rank_zero_deprecation, rank_zero_warn
 from pytorch_lightning.utilities.signature_utils import is_param_in_hook_signature
+from pytorch_lightning.utilities.warnings import PossibleUserWarning
 
 
 def verify_loop_configurations(trainer: "pl.Trainer") -> None:
@@ -117,7 +118,10 @@ def __verify_train_val_loop_configuration(trainer: "pl.Trainer", model: "pl.Ligh
     if has_val_loader and not has_val_step:
         rank_zero_warn("You passed in a `val_dataloader` but have no `validation_step`. Skipping val loop.")
     if has_val_step and not has_val_loader:
-        rank_zero_warn("You defined a `validation_step` but have no `val_dataloader`. Skipping val loop.")
+        rank_zero_warn(
+            "You defined a `validation_step` but have no `val_dataloader`. Skipping val loop.",
+            category=PossibleUserWarning,
+        )
 
 
 def _check_on_post_move_to_device(model: "pl.LightningModule") -> None:

tests/tests_pytorch/trainer/test_config_validator.py

@@ -18,6 +18,7 @@
 from pytorch_lightning.callbacks.callback import Callback
 from pytorch_lightning.demos.boring_classes import BoringDataModule, BoringModel, RandomDataset
 from pytorch_lightning.utilities.exceptions import MisconfigurationException
+from pytorch_lightning.utilities.warnings import PossibleUserWarning
 
 
 def test_wrong_train_setting(tmpdir):
@@ -59,7 +60,7 @@ def test_fit_val_loop_config(tmpdir):
         trainer.fit(model)
 
     # has val loop but no val data
-    with pytest.warns(UserWarning, match=r"You defined a `validation_step` but have no `val_dataloader`"):
+    with pytest.warns(PossibleUserWarning, match=r"You defined a `validation_step` but have no `val_dataloader`"):
         model = BoringModel()
         model.val_dataloader = None
         trainer.fit(model)