Allow doctest to deal with features requiring future server version (#797)

* Fix doctest for features requiring future server version.

* Make the unit_systems class treat the case of server version inferior to 6.1.

* Update conftest.py for doctest to treat unexpected DpfServerVersionNotSupported error.

* Update unit_system.py to create the unit_systems class only if possible.

* Revert UnitSystem requiring 6.2

* Do not try-catch the unit_systems class.

* Add a Required Version note in the uni_systems class docstring, and add a try-catch when trying to instantiate the UnitSystems, making the class empty for DPF server versions below 6.1

* Update src/ansys/dpf/core/unit_system.py

Author: PProfizi

conftest.py

@@ -3,6 +3,12 @@
 Launch or connect to a persistent local DPF service to be shared in
 pytest as a session fixture
 """
+import doctest
+from doctest import DocTestRunner
+from unittest import mock
+
+import pytest
+
 from ansys.dpf import core
 from ansys.dpf.core.misc import module_exists
 
@@ -17,3 +23,21 @@
 # enable off_screen plotting to avoid test interruption
 core.settings.disable_off_screen_rendering()
 core.settings.bypass_pv_opengl_osmesa_crash()
+
+
+class DPFDocTestRunner(DocTestRunner):
+    def run(self, test, compileflags=None, out=None, clear_globs=True):
+        try:
+            return DocTestRunner.run(self, test, compileflags, out, clear_globs)
+        except doctest.UnexpectedException as e:
+            feature_str = "Feature not supported. Upgrade the server to"
+            if feature_str in str(e.exc_info):
+                pass
+            else:
+                raise e
+
+
+@pytest.fixture(autouse=True)
+def doctest_runner_dpf():
+    with mock.patch("doctest.DocTestRunner", DPFDocTestRunner):
+        yield

src/ansys/dpf/core/unit_system.py

@@ -98,6 +98,10 @@ def unit_names(self) -> str:
 class unit_systems:
     """Contains common Ansys predefined UnitSystems.
 
+    Notes
+    -----
+    Class available with server's version starting at 6.1 (Ansys 2023R2).
+
     Attributes
     -----------
     solver_mks : Metric (m, kg, N, s, J, Pa, degC, C, rad)
@@ -118,11 +122,14 @@ class unit_systems:
 
     """
 
-    solver_mks = UnitSystem("solver_mks", ID=11)
-    solver_cgs = UnitSystem("solver_cgs", ID=5)
-    solver_nmm = UnitSystem("solver_nmm", ID=6)
-    solver_umks = UnitSystem("solver_umks", ID=10)
-    solver_knms = UnitSystem("solver_knms", ID=16)
-    solver_bft = UnitSystem("solver_bft", ID=7)
-    solver_bin = UnitSystem("solver_bin", ID=8)
-    undefined = UnitSystem("undefined", ID=-1)
+    try:
+        solver_mks = UnitSystem("solver_mks", ID=11)
+        solver_cgs = UnitSystem("solver_cgs", ID=5)
+        solver_nmm = UnitSystem("solver_nmm", ID=6)
+        solver_umks = UnitSystem("solver_umks", ID=10)
+        solver_knms = UnitSystem("solver_knms", ID=16)
+        solver_bft = UnitSystem("solver_bft", ID=7)
+        solver_bin = UnitSystem("solver_bin", ID=8)
+        undefined = UnitSystem("undefined", ID=-1)
+    except dpf_errors.DpfVersionNotSupported as e:  # pragma: no cover
+        pass