Removed test_dataloader call in check_testing_model_configuration (#1670)

* Removed test_dataloader call

* Check if test_dataloader is actually overriden

* Fixed method spelling

* Replaced lambdas

* Replaced None with super method

* Fixed testpass

pytorch_lightning/trainer/trainer.py

@@ -1054,7 +1054,7 @@ class Trainer(
 
         has_test_step = self.is_overridden('test_step', model)
         has_test_epoch_end = self.is_overridden('test_epoch_end', model)
-        gave_test_loader = hasattr(model, 'test_dataloader') and model.test_dataloader()
+        gave_test_loader = self.is_overridden('test_dataloader', model)
 
         if gave_test_loader and not has_test_step:
             raise MisconfigurationException('You passed in a `test_dataloader` but did not implement `test_step()`')

tests/trainer/test_checks.py

@@ -1,7 +1,7 @@
 import pytest
 
 import tests.base.utils as tutils
-from pytorch_lightning import Trainer
+from pytorch_lightning import Trainer, LightningModule
 from pytorch_lightning.utilities.exceptions import MisconfigurationException
 from tests.base import EvalModelTemplate
 
@@ -101,7 +101,7 @@ def test_wrong_test_settigs(tmpdir):
     # ----------------
     with pytest.raises(MisconfigurationException):
         model = EvalModelTemplate(hparams)
-        model.test_dataloader = lambda: None
+        model.test_dataloader = LightningModule.test_dataloader
         trainer.test(model)
 
     # ----------------
@@ -109,7 +109,7 @@ def test_wrong_test_settigs(tmpdir):
     # ----------------
     with pytest.raises(MisconfigurationException):
         model = EvalModelTemplate(hparams)
-        model.test_dataloader = lambda: None
+        model.test_dataloader = LightningModule.test_dataloader
         model.test_step = None
         trainer.test(model, test_dataloaders=model.dataloader(train=False))
 
@@ -118,6 +118,6 @@ def test_wrong_test_settigs(tmpdir):
     # ----------------
     with pytest.warns(RuntimeWarning):
         model = EvalModelTemplate(hparams)
-        model.test_dataloader = lambda: None
+        model.test_dataloader = LightningModule.test_dataloader
         model.test_epoch_end = None
         trainer.test(model, test_dataloaders=model.dataloader(train=False))

tests/trainer/test_trainer.py

@@ -457,7 +457,7 @@ def test_testpass_overrides(tmpdir):
     # Misconfig when neither test_step or test_end is implemented
     with pytest.raises(MisconfigurationException, match='.*not implement `test_dataloader`.*'):
         model = EvalModelTemplate(hparams)
-        model.test_dataloader = model.test_dataloader__empty
+        model.test_dataloader = LightningModule.test_dataloader
         Trainer().test(model)
 
     # Misconfig when neither test_step or test_end is implemented