Move Python test suite

interfaces/cython/SConscript

@@ -12,9 +12,6 @@ localenv = env.Clone()
 dataFiles = localenv.RecursiveInstall("cantera/data", "#build/data")
 build(dataFiles)
 
-testFiles = localenv.RecursiveInstall("cantera/test/data", "#test/data")
-build(testFiles)
-
 # Get information needed to build the Python module
 script = """\
 from sysconfig import *
@@ -116,13 +113,12 @@ mod = build(localenv.Command(f"#build/python/dist/{wheel_name}", "setup.cfg",
 env['python_module'] = mod
 env['python_extension'] = ext
 
-localenv.Depends(mod, [ext, dataFiles, testFiles, setup_cfg, readme, license,
-                       "setup.py", "pyproject.toml"])
+localenv.Depends(mod, [ext, dataFiles, setup_cfg, readme, license,
+                       "setup.py", "pyproject.toml", "cantera/test/README.txt"])
 localenv.Depends(ext, localenv['cantera_staticlib'])
 
 for f in (multi_glob(localenv, 'cantera', 'py') +
-          multi_glob(localenv, 'cantera/*', 'py') +
-          multi_glob(localenv, 'cantera/*/*', 'py')):
+          multi_glob(localenv, 'cantera/*', 'py')):
     localenv.Depends(mod, f)
 
 # Determine installation path and install the Python module

interfaces/cython/cantera/test/README.txt

@@ -0,0 +1,4 @@
+Starting with Cantera 3.0, the Python test suite is no longer packaged with the Python
+module. Unit tests can be accessed in the directory "test/python" of the source code,
+which can be retrieved from the project's GitHub repository
+(https://github.com/Cantera/cantera).

interfaces/cython/setup.cfg.in

@@ -47,18 +47,15 @@ python_requires = >=@py_min_ver_str@
 packages =
     cantera
     cantera.data
-    cantera.test
-    cantera.test.data
     cantera.examples
 
 [options.package_data]
 cantera.data = *.*, */*.*
-cantera.test.data = *.*, */*.*
 cantera.examples = */*.*
 # The module extension needs to be here since we don't want setuptools to
 # compile the extension, so there are no `source` files in
 # the setup.py extension.
-cantera = *.pxd, *@module_ext@
+cantera = *.pxd, *@module_ext@, test/*.txt
 
 [options.extras_require]
 hdf5 = h5py

interfaces/python_sdist/setup.cfg.in

@@ -47,16 +47,13 @@ python_requires = >=@py_min_ver_str@
 packages =
     cantera
     cantera.data
-    cantera.test
-    cantera.test.data
     cantera.examples
 
 # These options include data in the sdist and wheel if the files are also listed in
 # MANIFEST.in. Note that only files that are inside the "cantera" packages will be
 # included in the wheel.
 [options.package_data]
 cantera.data = *.*, */*.*
-cantera.test.data = *.*, */*.*
 cantera.examples = */*.*
 cantera = *.pxd
 

test/SConscript

@@ -292,7 +292,7 @@ addTestProgram('transport', 'transport')
 addTestProgram('zeroD', 'zeroD')
 
 python_subtests = ['']
-test_root = '#interfaces/cython/cantera/test'
+test_root = '#test/python'
 for f in multi_glob(localenv, test_root, '^test_*.py'):
     python_subtests.append(f.name[5:-3])
 

test/python/pytest.ini

@@ -0,0 +1,2 @@
+[pytest]
+pythonpath = ../../build/python

test/python/runCythonTests.py

@@ -1,21 +1,36 @@
 """
 Unit tests for Cantera's Cython-based Python module.
 
-This script gathers all the tests defined 'cantera.test' module, runs them,
-and prints a report. Extra command line arguments can be used to run subsets
-of the test suite, for example:
+This script is used by SCons to run the Python test suite, where ``pytest`` is used
+as the test runner. All arguments are handled by SCons configurations.
 
-all tests from 'test_thermo.py' and 'test_kinetics.py':
+This script gathers all Python tests, runs them, and prints a report::
+
+    python runCythonTests.py
+
+Extra command line arguments can be used to run subsets of the test suite, for example
+all tests from ``test_thermo.py`` and ``test_kinetics.py``::
 
     python runCythonTests.py thermo kinetics
 
-all tests from the 'test_reactor.TesTIdealGasReactor' class:
+As an alternative, tests can be run using ``pytest`` directly, as illustrated for the
+following examples (run from Cantera's root folder):
+
+all tests::
+
+    pytest test/python
+
+all tests from ``test_transport.py``::
+
+    pytest test/python/test_transport.py
+
+all tests from the ``test_reactor.TestIdealGasReactor`` class::
 
-    python runCythonTests.py reactor.TestIdealGasReactor
+    pytest test/python/test_reactor.py::TestIdealGasReactor
 
-a single test:
+a single test::
 
-    python runCythonTests.py onedim.TestDiffusionFlame.test_mixture_averaged
+    pytest test/python/test_onedim.py::TestDiffusionFlame::test_mixture_averaged
 """
 
 import sys
@@ -35,7 +50,6 @@
         sys.exit(21)  # test/SConscript has special handling for this error code
 
 import cantera
-import cantera.test
 
 if __name__ == "__main__":
     print("\n* INFO: using Cantera module found at this location:")
@@ -58,7 +72,7 @@
         verbose = True
         subset_start += 1
 
-    base = Path(cantera.__file__).parent.joinpath("test")
+    base = CANTERA_ROOT / "test" / "python"
     subsets = []
     for name in sys.argv[subset_start:]:
         subsets.append(str(base.joinpath(f"test_{name}.py")))

interfaces/cython/cantera/test/test_convert.py → test/python/test_convert.py

@@ -517,7 +517,7 @@ def test_error_for_big_element_number(self):
 
 class yaml2ckTest(utilities.CanteraTest):
     """Test yaml2ck by converting to CK then back to YAML to read with Cantera."""
-    ext: str = ".yaml2ck.yaml"
+    ext: str = "-from-yaml2ck.yaml"
 
     def _convert_to_ck(
         self,
@@ -527,7 +527,8 @@ def _convert_to_ck(
     ) -> tuple[Path | None, Path | None, Path | None]:
         mechanism_path: Path | str
         if not output:
-            mechanism_path = input_file.with_suffix(".ck")
+            stem = Path(input_file).stem  # strip '.inp'
+            mechanism_path = self.test_work_path / (stem + "-from-yaml.ck")
             thermo_path = transport_path = None
         else:
             if len(output) != 3:
@@ -559,12 +560,16 @@ def convert(
         transport: str | Path | None = None,
         permissive: bool = False,
     ) -> None:
-        mech, thermo, transport = self._convert_to_ck(
-            input_file,
-            phase_name,
-            (mech, thermo, transport),
-        )
-        output = input_file.with_suffix(self.ext)
+        if mech is not None:
+            mech, thermo, transport = self._convert_to_ck(
+                input_file,
+                phase_name,
+                (mech, thermo, transport),
+            )
+        else:
+            mech, thermo, transport = self._convert_to_ck(input_file, phase_name)
+
+        output = self.test_work_path / (Path(input_file).stem + self.ext)
         ck2yaml.convert_mech(
             mech,
             thermo_file=thermo,
@@ -581,7 +586,8 @@ def check_conversion(self, basename, cls=ct.Solution, **kwargs):
             phase_name = kwargs.pop("name")
         else:
             phase_name = ""
-        ck_phase = cls(basename.with_suffix(self.ext), **kwargs)
+        ckname = self.test_work_path / (basename.stem + self.ext)
+        ck_phase = cls(ckname, **kwargs)
         yaml_phase = cls(basename, phase_name, **kwargs)
 
         self.assertEqual(set(ck_phase.element_names), set(yaml_phase.element_names))

interfaces/cython/cantera/test/utilities.py → test/python/utilities.py

@@ -15,9 +15,11 @@
 
 slow_test = unittest.skipIf(environ.get("CT_SKIP_SLOW", "0") == "1", "slow test")
 
-TEST_DATA_PATH = Path(__file__).parent / "data"
-CANTERA_DATA_PATH = Path(__file__).parents[1] / "data"
+TEST_DATA_PATH = Path(__file__).parents[1] / "data"
+CANTERA_DATA_PATH = Path(__file__).parents[2] / "data"
 
+cantera.add_directory(TEST_DATA_PATH)
+cantera.add_directory(CANTERA_DATA_PATH)
 
 @pytest.fixture
 def allow_deprecated():