From 615b2f736303ad3cd56b33111f69952255f01c0f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Adrian=20W=C3=A4lchli?= <aedu.waelchli@gmail.com>
Date: Wed, 10 Mar 2021 00:18:38 +0100
Subject: [PATCH] Improve DummyLogger (#6398)

* fix dummy logger

* docs

* update docs

* add changelog

* add none return annotation

* return empty string for name, version
---
 CHANGELOG.md                             |  3 +++
 pytorch_lightning/loggers/base.py        | 34 +++++++++++++-----------
 tests/loggers/test_base.py               |  9 +++++++
 tests/trainer/flags/test_fast_dev_run.py |  1 +
 4 files changed, 31 insertions(+), 16 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index bdae336a18874..046e07cc55736 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -136,6 +136,9 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/).
 - Fixed `Trainer` not resetting `lightning_optimizers` when calling `Trainer.fit()` multiple times ([#6372](https://github.com/PyTorchLightning/pytorch-lightning/pull/6372))
 
 
+- Fixed `DummyLogger.log_hyperparams` raising a `TypeError` when running with `fast_dev_run=True` ([#6398](https://github.com/PyTorchLightning/pytorch-lightning/pull/6398))
+
+
 ## [1.2.2] - 2021-03-02
 
 ### Added
diff --git a/pytorch_lightning/loggers/base.py b/pytorch_lightning/loggers/base.py
index 4fdb5e8c437bf..035a42338fe68 100644
--- a/pytorch_lightning/loggers/base.py
+++ b/pytorch_lightning/loggers/base.py
@@ -279,12 +279,14 @@ def _sanitize_params(params: Dict[str, Any]) -> Dict[str, Any]:
         return params
 
     @abstractmethod
-    def log_hyperparams(self, params: argparse.Namespace):
+    def log_hyperparams(self, params: argparse.Namespace, *args, **kwargs):
         """
         Record hyperparameters.
 
         Args:
             params: :class:`~argparse.Namespace` containing the hyperparameters
+            args: Optional positional arguments, depends on the specific logger being used
+            kwargs: Optional keywoard arguments, depends on the specific logger being used
         """
 
     def log_graph(self, model: LightningModule, input_array=None) -> None:
@@ -418,41 +420,41 @@ def nop(*args, **kw):
     def __getattr__(self, _):
         return self.nop
 
-    def __getitem__(self, idx):
-        # enables self.logger[0].experiment.add_image
-        # and self.logger.experiment[0].add_image(...)
+    def __getitem__(self, idx) -> "DummyExperiment":
+        # enables self.logger.experiment[0].add_image(...)
         return self
 
 
 class DummyLogger(LightningLoggerBase):
-    """ Dummy logger for internal use. Is usefull if we want to disable users
-        logger for a feature, but still secure that users code can run """
+    """
+    Dummy logger for internal use. It is useful if we want to disable user's
+    logger for a feature, but still ensure that user code can run
+    """
 
     def __init__(self):
         super().__init__()
         self._experiment = DummyExperiment()
 
     @property
-    def experiment(self):
+    def experiment(self) -> DummyExperiment:
         return self._experiment
 
-    @rank_zero_only
-    def log_metrics(self, metrics, step):
+    def log_metrics(self, *args, **kwargs) -> None:
         pass
 
-    @rank_zero_only
-    def log_hyperparams(self, params):
+    def log_hyperparams(self, *args, **kwargs) -> None:
         pass
 
     @property
-    def name(self):
-        pass
+    def name(self) -> str:
+        return ""
 
     @property
-    def version(self):
-        pass
+    def version(self) -> str:
+        return ""
 
-    def __getitem__(self, idx):
+    def __getitem__(self, idx) -> "DummyLogger":
+        # enables self.logger[0].experiment.add_image(...)
         return self
 
 
diff --git a/tests/loggers/test_base.py b/tests/loggers/test_base.py
index c48fef5e04b49..cf3a0cb74b3f4 100644
--- a/tests/loggers/test_base.py
+++ b/tests/loggers/test_base.py
@@ -229,15 +229,24 @@ def log_metrics(self, metrics, step):
 
 
 def test_dummyexperiment_support_indexing():
+    """ Test that the DummyExperiment can imitate indexing the experiment in a LoggerCollection. """
     experiment = DummyExperiment()
     assert experiment[0] == experiment
 
 
 def test_dummylogger_support_indexing():
+    """ Test that the DummyLogger can imitate indexing of a LoggerCollection. """
     logger = DummyLogger()
     assert logger[0] == logger
 
 
+def test_dummylogger_noop_method_calls():
+    """ Test that the DummyLogger methods can be called with arbitrary arguments. """
+    logger = DummyLogger()
+    logger.log_hyperparams("1", 2, three="three")
+    logger.log_metrics("1", 2, three="three")
+
+
 def test_np_sanitization():
 
     class CustomParamsLogger(CustomLogger):
diff --git a/tests/trainer/flags/test_fast_dev_run.py b/tests/trainer/flags/test_fast_dev_run.py
index 09c5b58d363d9..9160d8d0f3d61 100644
--- a/tests/trainer/flags/test_fast_dev_run.py
+++ b/tests/trainer/flags/test_fast_dev_run.py
@@ -71,6 +71,7 @@ def test_step(self, batch, batch_idx):
     checkpoint_callback = ModelCheckpoint()
     early_stopping_callback = EarlyStopping()
     trainer_config = dict(
+        default_root_dir=tmpdir,
         fast_dev_run=fast_dev_run,
         val_check_interval=2,
         logger=True,