test: integration Trainer's resume fit ckpt with Prod

tests/integrations/test_cloud.py

@@ -14,6 +14,13 @@
 LIT_TEAMSPACE = "LitModels"
 
 
+def _prepare_variables(test_name: str) -> tuple[Teamspace, str, str]:
+    model_name = f"litmodels_test_integrations_{test_name}+{os.urandom(8).hex()}"
+    teamspace = _resolve_teamspace(org=LIT_ORG, teamspace=LIT_TEAMSPACE, user=None)
+    org_team = f"{teamspace.owner.name}/{teamspace.name}"
+    return teamspace, org_team, model_name
+
+
 def _cleanup_model(teamspace: Teamspace, model_name: str) -> None:
     """Cleanup model from the teamspace."""
     client = GridRestClient()
@@ -35,9 +42,7 @@ def test_upload_download_model(tmp_path):
         f.write("dummy")
 
     # model name with random hash
-    model_name = f"litmodels_test_integrations+{os.urandom(8).hex()}"
-    teamspace = _resolve_teamspace(org=LIT_ORG, teamspace=LIT_TEAMSPACE, user=None)
-    org_team = f"{teamspace.owner.name}/{teamspace.name}"
+    teamspace, org_team, model_name = _prepare_variables("upload_download")
 
     out = StringIO()
     with redirect_stdout(out):
@@ -78,9 +83,7 @@ def test_lightning_default_checkpointing(importing, tmp_path):
         from pytorch_lightning.demos.boring_classes import BoringModel
 
     # model name with random hash
-    model_name = f"litmodels_test_integrations+{os.urandom(8).hex()}"
-    teamspace = _resolve_teamspace(org=LIT_ORG, teamspace=LIT_TEAMSPACE, user=None)
-    org_team = f"{teamspace.owner.name}/{teamspace.name}"
+    teamspace, org_team, model_name = _prepare_variables("default_checkpoint")
 
     trainer = Trainer(
         max_epochs=2,
@@ -91,3 +94,40 @@ def test_lightning_default_checkpointing(importing, tmp_path):
 
     # CLEANING
     _cleanup_model(teamspace, model_name)
+
+
+@pytest.mark.parametrize(
+    "registry", ["registry", "registry:version:v1", "registry:<model>", "registry:<model>:version:v1"]
+)
+@pytest.mark.parametrize(
+    "importing",
+    [
+        pytest.param("lightning", marks=_SKIP_IF_LIGHTNING_BELLOW_2_5_1),
+        pytest.param("pytorch_lightning", marks=_SKIP_IF_PYTORCHLIGHTNING_BELLOW_2_5_1),
+    ],
+)
+@pytest.mark.cloud()
+# todo: mock env variables as it would run in studio
+def test_lightning_resume(importing, registry, tmp_path):
+    if importing == "lightning":
+        from lightning import Trainer
+        from lightning.pytorch.demos.boring_classes import BoringModel
+    elif importing == "pytorch_lightning":
+        from pytorch_lightning import Trainer
+        from pytorch_lightning.demos.boring_classes import BoringModel
+
+    trainer = Trainer(max_epochs=1, default_root_dir=tmp_path)
+    trainer.fit(BoringModel())
+    checkpoint_path = getattr(trainer.checkpoint_callback, "best_model_path")
+
+    # model name with random hash
+    teamspace, org_team, model_name = _prepare_variables("resume")
+    upload_model(model=checkpoint_path, name=f"{org_team}/{model_name}")
+
+    trainer_kwargs = {"model_registry": f"{org_team}/{model_name}"} if "<model>" not in registry else {}
+    trainer = Trainer(max_epochs=2, default_root_dir=tmp_path, **trainer_kwargs)
+    registry = registry.replace("<model>", f"{org_team}/{model_name}")
+    trainer.fit(BoringModel(), ckpt_path=registry)
+
+    # CLEANING
+    _cleanup_model(teamspace, model_name)