Merge pull request #415 from mcgalcode/bugfix/blank-yaml

Add warning when jobflow.yaml is blank or badly formatted

pyproject.toml

@@ -46,7 +46,7 @@ docs = [
     "sphinx==7.2.4",
 ]
 dev = ["pre-commit>=2.12.1"]
-tests = ["pytest-cov==4.1.0", "pytest==7.4.0"]
+tests = ["pytest-cov==4.1.0", "pytest==7.4.0", "moto==4.2.0"]
 vis = ["matplotlib", "pydot"]
 fireworks = ["FireWorks"]
 strict = [

src/jobflow/settings.py

@@ -1,5 +1,6 @@
 """Settings for jobflow."""
 
+import warnings
 from collections import defaultdict
 from pathlib import Path
 
@@ -136,10 +137,21 @@ def load_default_settings(cls, values):
         from monty.serialization import loadfn
 
         config_file_path: str = values.get("CONFIG_FILE", DEFAULT_CONFIG_FILE_PATH)
-
         new_values = {}
         if Path(config_file_path).exists():
-            new_values.update(loadfn(config_file_path))
+            if Path(config_file_path).stat().st_size == 0:
+                warnings.warn(
+                    f"An empty JobFlow config file was located at {config_file_path}"
+                )
+            else:
+                try:
+                    new_values.update(loadfn(config_file_path))
+                except ValueError:
+                    raise ValueError(
+                        f"A JobFlow configuration file was located at "
+                        f"{config_file_path} but a problem was "
+                        f"encountered while parsing it."
+                    ) from None
 
         store = new_values.get("JOB_STORE")
         if isinstance(store, str):

tests/test_settings.py

@@ -1,3 +1,6 @@
+import pytest
+
+
 def test_settings_init():
     import os
 
@@ -69,7 +72,23 @@ def test_settings_object(clean_dir, test_data):
     }
 
     # set the path to lood settings from
-    os.environ["JOBFLOW_CONFIG_FILE"] = str(Path.cwd() / "config.yaml")
+    config_file_path = str(Path.cwd() / "config.yaml")
+    os.environ["JOBFLOW_CONFIG_FILE"] = config_file_path
+
+    # A warning should appear if config file is empty
+    with open(config_file_path, "w") as f:
+        pass
+
+    with pytest.warns(UserWarning):
+        settings = JobflowSettings()
+
+    # An error should be thrown if the file exists and
+    # contains badly formatted contents
+    with open(config_file_path, "w") as f:
+        f.write("Some text that sadly is not yaml")
+
+    with pytest.raises(ValueError, match="A JobFlow configuration"):
+        settings = JobflowSettings()
 
     # assert loading monty spec from files works
     dumpfn({"JOB_STORE": monty_spec}, "config.yaml")