Refactor Python tests to make consistent use of pytest ECFLOW-2110

.github/ci-config.yml

@@ -20,3 +20,9 @@ dependencies: |
 dependency_branch: develop
 
 parallelism_factor: 8
+
+python_requirements: libs/pyext/test/requirements-test.txt
+
+overrides:
+  rocky-8.6:
+    python_version: "3.11"

.github/ci-hpc-config.yml

@@ -12,6 +12,7 @@ build:
     - -DENABLE_ALL_TESTS=ON
   ctest_options:
     - -L nightly
+  requirements: libs/pyext/test/requirements-test.txt
 
 gnu-15.2.0:
   build:
@@ -37,10 +38,12 @@ gnu-15.2.0:
         -DPython3_LIBRARIES=/usr/local/apps/python3/3.13.13-01/lib64/libpython3.13.so
         -DPython3_LIBRARY_DIRS=/usr/local/apps/python3/3.13.13-01/lib64
         -DCMAKE_PREFIX_PATH=/usr/local/apps/python3/3.13.13-01/lib/python3.13/site-packages/pybind11/share/cmake/pybind11
+        -DECFLOW_PYEXT_TEST_LD_LIBRARY_PATH=/usr/local/apps/gcc/15.2.0/lib64
       # Note: Python 3.13.13-01, provides Pybind11 3.0.4.
     ctest_options:
       # disable s_http* tests
       - -L nightly -E '(s_http)'
+    requirements: libs/pyext/test/requirements-test.txt
 
 gnu-14.2.0:
   build:
@@ -65,6 +68,7 @@ gnu-14.2.0:
         -DPython3_LIBRARIES=/usr/local/apps/python3/3.12.9-01/lib64/libpython3.12.so
         -DPython3_LIBRARY_DIRS=/usr/local/apps/python3/3.12.9-01/lib64
         -DCMAKE_PREFIX_PATH=/usr/local/apps/python3/3.13.13-01/lib/python3.13/site-packages/pybind11/share/cmake/pybind11
+        -DECFLOW_PYEXT_TEST_LD_LIBRARY_PATH=/usr/local/apps/gcc/14.2.0/lib64
       # Note: Python 3.13.13-01, provides Pybind11 3.0.4.
       #
       # Important:
@@ -73,6 +77,7 @@ gnu-14.2.0:
     ctest_options:
       # disable s_http* tests
       - -L nightly -E '(s_http)'
+    requirements: libs/pyext/test/requirements-test.txt
 
 gnu-12.2.0:
   build:
@@ -101,6 +106,7 @@ gnu-12.2.0:
     ctest_options:
       # disable s_http* tests
       - -L nightly -E '(s_http)'
+    requirements: libs/pyext/test/requirements-test.txt
 
 gnu-8.5.0:
   build:
@@ -129,6 +135,7 @@ gnu-8.5.0:
     ctest_options:
       # disable s_http* tests
       - -L nightly -E '(s_http)'
+    requirements: libs/pyext/test/requirements-test.txt
 
 intel-2025.3.1:
   build:
@@ -159,6 +166,7 @@ intel-2025.3.1:
     ctest_options:
       # disable s_http* tests
       - -L nightly -E '(s_http)'
+    requirements: libs/pyext/test/requirements-test.txt
 
 intel-2025.0.1:
   build:
@@ -192,6 +200,7 @@ intel-2025.0.1:
     ctest_options:
       # disable s_http* tests
       - -L nightly -E '(s_http)'
+    requirements: libs/pyext/test/requirements-test.txt
 
 intel-2021.4.0:
   build:
@@ -220,6 +229,7 @@ intel-2021.4.0:
       # Note: Python 3.10.10-01, provides Pybind11 2.10.3.
     ctest_options:
       - -L nightly -E '(py3_|s_http)'
+    requirements: libs/pyext/test/requirements-test.txt
 
 nvidia-24.11:
   build:
@@ -252,6 +262,7 @@ nvidia-24.11:
     ctest_options:
       # disable all tests
       - --version
+    requirements: libs/pyext/test/requirements-test.txt
 
 nvidia-22.11:
   build:
@@ -280,6 +291,7 @@ nvidia-22.11:
     ctest_options: 
       # disable all tests
       - --version
+    requirements: libs/pyext/test/requirements-test.txt
 
 aocc-4.0.0:
   build:
@@ -308,3 +320,4 @@ aocc-4.0.0:
     ctest_options:
       # disable all tests
       - --version
+    requirements: libs/pyext/test/requirements-test.txt

.github/workflows/ci.yml

@@ -27,7 +27,7 @@ jobs:
   downstream-ci:
     name: downstream-ci
     if: ${{ !github.event.pull_request.head.repo.fork && github.event.action != 'labeled' || github.event.label.name == 'approved-for-ci' }}
-    uses: ecmwf/downstream-ci/.github/workflows/downstream-ci.yml@main
+    uses: ecmwf/downstream-ci/.github/workflows/downstream-ci.yml@test-ecflow-py
     with:
       ecflow: ecmwf/ecflow@${{ github.event.pull_request.head.sha || github.sha }}
       skip_matrix_jobs: |
@@ -49,7 +49,7 @@ jobs:
   downstream-ci-hpc:
     name: downstream-ci-hpc
     if: ${{ !github.event.pull_request.head.repo.fork && github.event.action != 'labeled' || github.event.label.name == 'approved-for-ci' }}
-    uses: ecmwf/downstream-ci/.github/workflows/downstream-ci-hpc.yml@main
+    uses: ecmwf/downstream-ci/.github/workflows/downstream-ci-hpc.yml@test-ecflow-py
     with:
       ecflow: ecmwf/ecflow@${{ github.event.pull_request.head.sha || github.sha }}
       skip_matrix_jobs: |

libs/pyext/python3/CMakeLists.txt

@@ -62,6 +62,48 @@ set_target_properties(ecflow3
 # =====================================================================
 # tests
 
+# The python tests are executed via 'python -m pytest' (see below), so
+# pytest must be available for the selected interpreter. Detect it at configure
+# time and warn early, rather than having every py3_u_* / py3_s_* test fail at run time
+# with 'No module named pytest'.
+execute_process(
+  COMMAND ${Python3_EXECUTABLE} -c "import pytest"
+  RESULT_VARIABLE _ECFLOW_HAVE_PYTEST
+  OUTPUT_QUIET ERROR_QUIET)
+if( NOT _ECFLOW_HAVE_PYTEST EQUAL 0 )
+  message( WARNING
+    "pytest was not found for ${Python3_EXECUTABLE}; the python tests "
+    "(py3_u_* and py3_s_*) will fail to run. Install it with:\n"
+    "    ${Python3_EXECUTABLE} -m pip install -r "
+    "${CMAKE_CURRENT_SOURCE_DIR}/../test/requirements-test.txt" )
+endif()
+
+#
+# When using some HPC toolchains, the dynamic linker for ecflow resolves and loads the platform default libstdc++ first,
+# instead of the one that ecflow.so was built against. This leads to symbol version mismatches, and the python tests
+# fail with errors like:
+#
+#   /lib64/libstdc++.so.6: error: version lookup error: version `GLIBCXX_3.4.32' not found
+#     (required by /path/to/ecflow/build/libs/pyext/python3/ecflow.so) (fatal)
+#
+# ECFLOW_PYEXT_TEST_LD_LIBRARY_PATH allows a runtime library directory to be prepended to LD_LIBRARY_PATH, so that
+# the correct libstdc++.so.6 is used by the python tests.
+#
+set(ECFLOW_PYEXT_TEST_LD_LIBRARY_PATH "" CACHE STRING
+  "Colon-separated directories prepended to LD_LIBRARY_PATH when running the python tests")
+
+set( _ECFLOW_PYEXT_ENVIRONMENT
+  "PATH=${Python3_EXECUTABLE_DIR}:$ENV{PATH}"
+  "PYTHONPATH=${ECFLOW_PYTHONPATH}"
+)
+if( ECFLOW_PYEXT_TEST_LD_LIBRARY_PATH )
+  if( DEFINED ENV{LD_LIBRARY_PATH} AND NOT "$ENV{LD_LIBRARY_PATH}" STREQUAL "" )
+    list( APPEND _ECFLOW_PYEXT_ENVIRONMENT "LD_LIBRARY_PATH=${ECFLOW_PYEXT_TEST_LD_LIBRARY_PATH}:$ENV{LD_LIBRARY_PATH}" )
+  else()
+    list( APPEND _ECFLOW_PYEXT_ENVIRONMENT "LD_LIBRARY_PATH=${ECFLOW_PYEXT_TEST_LD_LIBRARY_PATH}" )
+  endif()
+endif()
+
 foreach( test ${u_tests} )
   ecbuild_add_test(
     TARGET
@@ -70,9 +112,9 @@ foreach( test ${u_tests} )
       unit python nightly fast
     TYPE PYTHON
     ARGS
-      ${CMAKE_CURRENT_SOURCE_DIR}/../test/py_${test}.py
+      -m pytest ${CMAKE_CURRENT_SOURCE_DIR}/../test/py_${test}.py -v
     ENVIRONMENT
-      "PATH=${Python3_EXECUTABLE_DIR}:$ENV{PATH};PYTHONPATH=${ECFLOW_PYTHONPATH}"
+      ${_ECFLOW_PYEXT_ENVIRONMENT}
     TEST_DEPENDS
       u_base
   )
@@ -81,6 +123,11 @@ endforeach()
 
 if ( ENABLE_ALL_TESTS AND ENABLE_SERVER)
 
+  #
+  # Python integration tests run the ecflow server, and thus use ECF_SSL_DIR to find the generated SSL certificates.
+  #
+  list( APPEND _ECFLOW_PYEXT_ENVIRONMENT "ECF_SSL_DIR=${CMAKE_CURRENT_BINARY_DIR}/" )
+
   foreach( test ${s_tests} )
     ecbuild_add_test(
       TARGET
@@ -89,9 +136,9 @@ if ( ENABLE_ALL_TESTS AND ENABLE_SERVER)
         integration python nightly slow
       TYPE PYTHON
       ARGS
-        ${CMAKE_CURRENT_SOURCE_DIR}/../test/py_${test}.py
+        -m pytest ${CMAKE_CURRENT_SOURCE_DIR}/../test/py_${test}.py -v
       ENVIRONMENT
-        "PATH=${Python3_EXECUTABLE_DIR}:$ENV{PATH};PYTHONPATH=${ECFLOW_PYTHONPATH};ECF_SSL_DIR=${CMAKE_CURRENT_BINARY_DIR}/"
+        ${_ECFLOW_PYEXT_ENVIRONMENT}
       TEST_DEPENDS
         u_base
     )

libs/pyext/test/conftest.py

@@ -0,0 +1,29 @@
+#
+# Copyright 2009- ECMWF.
+#
+# This software is licensed under the terms of the Apache Licence version 2.0
+# which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
+# In applying this licence, ECMWF does not waive the privileges and immunities
+# granted to it by virtue of its status as an intergovernmental organisation
+# nor does it submit to any jurisdiction.
+#
+
+"""
+Shared pytest configuration for the ecFlow Python binding tests.
+
+This file is intentionally minimal.  Most unit tests only need a working
+``import ecflow`` and use bare ``assert`` statements.  Global fixtures or
+hooks should only be added here when they are genuinely shared across many
+files.
+"""
+
+import pytest # to ensure pytest is available
+
+def pytest_configure(config):
+    """Ensure ecflow is importable before any test is collected."""
+    try:
+        import ecflow  # noqa: F401
+    except ImportError as exc:
+        raise RuntimeError(
+            "Could not import ecflow. Make sure the binding is on PYTHONPATH."
+        ) from exc