Harden the TestRecentlyGeneratedCanteraYaml*GasOnly tests.

If we can't find the test files:
1. if the functional test that should have made them has been collected,
   e.g. you're running `make test-all` or in the CI runner, then this
   counts as a failure.
2. if the test that should have made them has not been collected, 
   e.g. you're just running this test on its own, or with `make test`
   then just mark the test as a "skip" and don't fail.

Author: rwest

test/rmgpy/yaml_cantera1Test.py

@@ -562,7 +562,7 @@ class TestPreviouslyWrittenCanteraYamlGasOnly(CanteraYamlFileComparer):
     yaml_path_1 = os.path.join(test_data_folder, 'chemkin/chem37.yaml')
     yaml_path_2 = os.path.join(test_data_folder, 'cantera1/chem37.yaml')
 
-class TestRecentlyGeneratedCanteraYamlGasOnly(CanteraYamlFileComparer):
+class TestRecentlyGeneratedCanteraYaml1GasOnly(CanteraYamlFileComparer):
     """Tests for comparing recently generated Cantera YAML files, gas-only mechanism.
 
     These are generated on the fly in the mainTest.py functional test and stored in the testing data directory.
@@ -571,20 +571,30 @@ class TestRecentlyGeneratedCanteraYamlGasOnly(CanteraYamlFileComparer):
 
     @pytest.fixture(autouse=True, scope="class")
     def find_recent_files(self, request):
-        """Find the YAML files generated by mainTest."""
-        cantera_dir = os.path.join(self.test_data_folder, 'cantera1')
-        chemkin_dir = os.path.join(self.test_data_folder, 'ck2yaml')
-        
-        if not os.path.exists(cantera_dir) or not os.path.exists(chemkin_dir):
-            pytest.skip("YAML test data directories not found. Run mainTest first.")
-        
-        # Look for specifically named files from mainTest
-        cantera_file = os.path.join(cantera_dir, 'from_main_test.yaml')
-        chemkin_file = os.path.join(chemkin_dir, 'from_main_test.yaml')
-        
-        if not os.path.exists(cantera_file) or not os.path.exists(chemkin_file):
+        """
+        Find the YAML files generated by mainTest.
+        """
+        cantera_file = os.path.join(self.test_data_folder, 'cantera1', 'from_main_test.yaml')
+        chemkin_file = os.path.join(self.test_data_folder, 'ck2yaml', 'from_main_test.yaml')
+
+        if not (os.path.exists(cantera_file) and os.path.exists(chemkin_file)):
+            # If mainTest's copy step was collected for this pytest session but the
+            # files are still missing, treat that as a failure rather than a skip —
+            # it means mainTest ran but didn't produce the expected output.
+            # (if using pytest-randomly or pytest-ordering to reorder them this will need altering).
+            main_test_collected = any(
+                item.name == "test_cantera_input_files_match_chemkin_later"
+                for item in request.session.items
+            )
+            if main_test_collected:
+                pytest.fail(
+                    "from_main_test.yaml files missing even though mainTest's "
+                    "copy step was collected — it likely failed before copying."
+                )
+            # If mainTest wasn't collected, it's likely that we're running this test 
+            # in isolation, so skip without failing.
             pytest.skip("from_main_test.yaml files not found. Run mainTest first.")
-        
+
         request.cls.yaml_path_1 = chemkin_file
         request.cls.yaml_path_2 = cantera_file
 

test/rmgpy/yaml_cantera2Test.py

@@ -778,17 +778,28 @@ class TestRecentlyGeneratedCanteraYaml2GasOnly(CanteraYamlFileComparer):
 
     @pytest.fixture(autouse=True, scope="class")
     def find_recent_files(self, request):
-        """Find the YAML files generated by mainTest."""
-        cantera_dir = os.path.join(self.test_data_folder, 'cantera2')
-        chemkin_dir = os.path.join(self.test_data_folder, 'ck2yaml')
-
-        if not os.path.exists(cantera_dir) or not os.path.exists(chemkin_dir):
-            pytest.skip("YAML test data directories not found. Run mainTest first.")
-
-        cantera_file = os.path.join(cantera_dir, 'from_main_test.yaml')
-        chemkin_file = os.path.join(chemkin_dir, 'from_main_test.yaml')
-
-        if not os.path.exists(cantera_file) or not os.path.exists(chemkin_file):
+        """
+        Find the YAML files generated by mainTest.
+        """
+        cantera_file = os.path.join(self.test_data_folder, 'cantera2', 'from_main_test.yaml')
+        chemkin_file = os.path.join(self.test_data_folder, 'ck2yaml', 'from_main_test.yaml')
+
+        if not (os.path.exists(cantera_file) and os.path.exists(chemkin_file)):
+            # If mainTest's copy step was collected for this pytest session but the
+            # files are still missing, treat that as a failure rather than a skip —
+            # it means mainTest ran but didn't produce the expected output.
+            # (if using pytest-randomly or pytest-ordering to reorder them this will need altering).
+            main_test_collected = any(
+                item.name == "test_cantera_input_files_match_chemkin_later"
+                for item in request.session.items
+            )
+            if main_test_collected:
+                pytest.fail(
+                    "from_main_test.yaml files missing even though mainTest's "
+                    "copy step was collected — it likely failed before copying."
+                )
+            # If mainTest wasn't collected, it's likely that we're running this test
+            # in isolation, so skip without failing.
             pytest.skip("from_main_test.yaml files not found. Run mainTest first.")
 
         request.cls.yaml_path_1 = chemkin_file