Cleaner datadir management for some tests (#15791)

src/pytorch_lightning/demos/boring_classes.py

@@ -156,11 +156,8 @@ def predict_dataloader(self) -> DataLoader:
 
 
 class BoringDataModule(LightningDataModule):
-    def __init__(self, data_dir: str = "./"):
+    def __init__(self) -> None:
         super().__init__()
-        self.data_dir = data_dir
-        self.non_picklable = None
-        self.checkpoint_state: Optional[str] = None
         self.random_full = RandomDataset(32, 64 * 4)
 
     def setup(self, stage: str) -> None:

src/pytorch_lightning/loggers/csv_logs.py

@@ -26,6 +26,7 @@
 
 from torch import Tensor
 
+from lightning_lite.utilities.types import _PATH
 from pytorch_lightning.core.saving import save_hparams_to_yaml
 from pytorch_lightning.loggers.logger import Logger, rank_zero_experiment
 from pytorch_lightning.utilities.logger import _add_prefix, _convert_params
@@ -125,14 +126,14 @@ class CSVLogger(Logger):
 
     def __init__(
         self,
-        save_dir: str,
+        save_dir: _PATH,
         name: str = "lightning_logs",
         version: Optional[Union[int, str]] = None,
         prefix: str = "",
         flush_logs_every_n_steps: int = 100,
     ):
         super().__init__()
-        self._save_dir = save_dir
+        self._save_dir = os.fspath(save_dir)
         self._name = name or ""
         self._version = version
         self._prefix = prefix

tests/tests_pytorch/core/test_datamodules.py

@@ -126,18 +126,24 @@ def test_helper_boringdatamodule_with_verbose_setup():
     dm.setup("test")
 
 
+class DataDirDataModule(BoringDataModule):
+    def __init__(self, data_dir: str):
+        super().__init__()
+        self.data_dir = data_dir
+
+
 def test_dm_add_argparse_args(tmpdir):
     parser = ArgumentParser()
-    parser = BoringDataModule.add_argparse_args(parser)
+    parser = DataDirDataModule.add_argparse_args(parser)
     args = parser.parse_args(["--data_dir", str(tmpdir)])
     assert args.data_dir == str(tmpdir)
 
 
 def test_dm_init_from_argparse_args(tmpdir):
     parser = ArgumentParser()
-    parser = BoringDataModule.add_argparse_args(parser)
+    parser = DataDirDataModule.add_argparse_args(parser)
     args = parser.parse_args(["--data_dir", str(tmpdir)])
-    dm = BoringDataModule.from_argparse_args(args)
+    dm = DataDirDataModule.from_argparse_args(args)
     dm.prepare_data()
     dm.setup("fit")
     assert dm.data_dir == args.data_dir == str(tmpdir)