Fix COMET_EXPERIMENT_KEY environment variable usage in comet logger

[Vozf]

What does this PR do?

Fixes #4229 (issue)

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[Lothiraldan]

This looks good, we should probably add a test for it.

[Borda]

could we pls add a test to show failing master and this is the fixes... 🐰

[tchaton]

Hey @Vozf, Could you add a tests by any chance ?

[Vozf]

Not really. Made this pr based on my personal inherited cometLogger class and I don't even have a setup for PytorchLightning project. I am also not familiar with your testing setup

[Lothiraldan]

I've worked on a test for this PR, it's a bit more complex than needed because the experiment key is not passed as a parameter to the Experiment class, I don't know what is the best way to send it to this PR. Here is the patch if someone with the right permission can push it to this PR:

diff --git a/tests/loggers/test_comet.py b/tests/loggers/test_comet.py
index dc66f184..3d13c6df 100644
--- a/tests/loggers/test_comet.py
+++ b/tests/loggers/test_comet.py
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import os
-from unittest.mock import patch
+from unittest.mock import patch, DEFAULT
 
 import pytest
 
@@ -25,6 +25,7 @@ from tests.base import EvalModelTemplate
 def _patch_comet_atexit(monkeypatch):
     """ Prevent comet logger from trying to print at exit, since pytest's stdout/stderr redirection breaks it. """
     import atexit
+
     monkeypatch.setattr(atexit, "register", lambda _: None)
 
 
@@ -99,6 +100,37 @@ def test_comet_logger_experiment_name(comet):
         comet_experiment().set_name.assert_called_once_with(experiment_name)
 
 
+@patch('pytorch_lightning.loggers.comet.comet_ml')
+def test_comet_logger_manual_experiment_key(comet):
+    """Test that Comet Logger respects manually set COMET_EXPERIMENT_KEY."""
+
+    api_key = "key"
+    experiment_key = "96346da91469407a85641afe5766b554"
+
+    instantation_environ = {}
+
+    def save_os_environ(*args, **kwargs):
+        nonlocal instantation_environ
+        instantation_environ = os.environ.copy()
+
+        return DEFAULT
+
+    # Test api_key given
+    with patch.dict(os.environ, {"COMET_EXPERIMENT_KEY": experiment_key}):
+        with patch('pytorch_lightning.loggers.comet.CometExperiment', side_effect=save_os_environ) as comet_experiment:
+            logger = CometLogger(api_key=api_key)
+
+            assert logger.version == experiment_key
+
+            assert logger._experiment is None
+
+            _ = logger.experiment
+
+            comet_experiment.assert_called_once_with(api_key=api_key, project_name=None)
+
+    assert instantation_environ["COMET_EXPERIMENT_KEY"] == experiment_key
+
+
 @patch('pytorch_lightning.loggers.comet.CometOfflineExperiment')
 @patch('pytorch_lightning.loggers.comet.comet_ml')
 def test_comet_logger_dirs_creation(comet, comet_experiment, tmpdir, monkeypatch):

[codecov]

Codecov Report

Merging #4230 into master will increase coverage by 0%.
The diff coverage is 100%.

@@          Coverage Diff           @@
##           master   #4230   +/-   ##
======================================
  Coverage      93%     93%           
======================================
  Files         111     111           
  Lines        8130    8102   -28     
======================================
- Hits         7524    7512   -12     
+ Misses        606     590   -16     

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