Mark Trainer.run_stage as protected

CHANGELOG.md

@@ -143,6 +143,9 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/).
 - Deprecated `ModelIO.on_hpc_{save/load}` in favor of `CheckpointHooks.on_{save/load}_checkpoint` ([#10911](https://github.com/PyTorchLightning/pytorch-lightning/pull/10911))
 
 
+- Deprecated `Trainer.run_stage` in favor of `Trainer.{fit,validate,test,predict}` ([#11000](https://github.com/PyTorchLightning/pytorch-lightning/pull/11000))
+
+
 ### Removed
 
 - Removed deprecated parameter `method` in `pytorch_lightning.utilities.model_helpers.is_overridden` ([#10507](https://github.com/PyTorchLightning/pytorch-lightning/pull/10507))

pytorch_lightning/trainer/trainer.py

@@ -1129,7 +1129,7 @@ def _run(
                         setup accelerator                     ||
                            and strategy                       ||  LIGHTNING
                                 |                             ||
-                         {self.run_stage}                     ||  FLOW
+                         {self._run_stage}                     ||  FLOW
                                 |                             ||
                         {self._run_train}                     ||  DIRECTION
                      or {self._run_evaluate}                  ||
@@ -1164,7 +1164,7 @@ def _run(
 
         self.checkpoint_connector.resume_end()
 
-        results = self.run_stage()
+        results = self._run_stage()
         self._teardown()
 
         # ----------------------------
@@ -1237,7 +1237,14 @@ def _teardown(self):
         self.logger_connector.teardown()
         self.signal_connector.teardown()
 
-    def run_stage(self):
+    def run_stage(self) -> None:
+        rank_zero_deprecation(
+            "`Trainer.run_stage` is deprecated in v1.6 and will be removed in v1.8. Use"
+            " `Trainer.{fit,validate,test,predict}` instead."
+        )
+        return self._run_stage()
+
+    def _run_stage(self):
         self.training_type_plugin.barrier("run-stage")
         self.training_type_plugin.dispatch(self)
         self.__setup_profiler()

tests/deprecated_api/test_remove_1-8.py

@@ -12,6 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 """Test deprecated functionality which will be removed in v1.8.0."""
+from unittest.mock import Mock
 
 import pytest
 import torch
@@ -106,3 +107,10 @@ def on_hpc_load(self):
         match=r"Method `LightningModule.on_hpc_load` is deprecated in v1.6 and will be removed in v1.8."
     ):
         trainer.fit(load_model)
+
+
+def test_v1_8_0_deprecated_run_stage():
+    trainer = Trainer()
+    trainer._run_stage = Mock()
+    with pytest.deprecated_call(match="`Trainer.run_stage` is deprecated in v1.6 and will be removed in v1.8."):
+        trainer.run_stage()