Replace nose with pytest

lib/iris/tests/__init__.py

@@ -1218,10 +1218,6 @@ class IrisTest(IrisTest_nometa, metaclass=_TestTimingsMetaclass):
 
 
 class GraphicsTestMixin:
-
-    # nose directive: dispatch tests concurrently.
-    _multiprocess_can_split_ = True
-
     def setUp(self):
         # Acquire threading non re-entrant blocking lock to ensure
         # thread-safe plotting.

lib/iris/tests/runner/_runner.py

@@ -10,17 +10,16 @@
 
 # Because this file is imported by setup.py, there may be additional runtime
 # imports later in the file.
-import multiprocessing
 import os
 import sys
 
 
 # NOTE: Do not inherit from object as distutils does not like it.
 class TestRunner:
-    """Run the Iris tests under nose and multiprocessor for performance"""
+    """Run the Iris tests under pytest and pytest-xdist for performance"""
 
     description = (
-        "Run tests under nose and multiprocessor for performance. "
+        "Run tests under pytest and pytest-xdist for performance. "
         "Default behaviour is to run all non-gallery tests. "
         "Specifying one or more test flags will run *only* those "
         "tests."
@@ -70,8 +69,8 @@ def initialize_options(self):
         self.create_missing = False
 
     def finalize_options(self):
-        # These enviroment variables will be propagated to all the
-        # processes that nose.run creates.
+        # These environment variables will be propagated to all the
+        # processes that pytest-xdist creates.
         if self.no_data:
             print("Running tests in no-data mode...")
             import iris.config
@@ -95,25 +94,23 @@ def finalize_options(self):
         if self.stop:
             print("Stopping tests after the first error or failure")
         if self.num_processors is None:
-            # Choose a magic number that works reasonably well for the default
-            # number of processes.
-            self.num_processors = (multiprocessing.cpu_count() + 1) // 4 + 1
+            self.num_processors = "auto"
         else:
             self.num_processors = int(self.num_processors)
 
     def run(self):
-        import nose
+        import pytest
 
         if hasattr(self, "distribution") and self.distribution.tests_require:
             self.distribution.fetch_build_eggs(self.distribution.tests_require)
 
         tests = []
         if self.system_tests:
-            tests.append("iris.tests.system_test")
+            tests.append("lib/iris/tests/system_test.py")
         if self.default_tests:
-            tests.append("iris.tests")
+            tests.append("lib/iris/tests")
         if self.coding_tests:
-            tests.append("iris.tests.test_coding_standards")
+            tests.append("lib/iris/tests/test_coding_standards.py")
         if self.gallery_tests:
             import iris.config
 
@@ -129,35 +126,25 @@ def run(self):
                     "WARNING: Gallery path %s does not exist." % (gallery_path)
                 )
         if not tests:
-            tests.append("iris.tests")
-
-        regexp_pat = r"--match=^([Tt]est(?![Mm]ixin)|[Ss]ystem)"
-
-        n_processors = max(self.num_processors, 1)
+            tests.append("lib/iris/tests")
 
         args = [
-            "",
             None,
-            "--processes=%s" % n_processors,
-            "--verbosity=2",
-            regexp_pat,
-            "--process-timeout=180",
+            "-v",
+            f"-n={self.num_processors}",
         ]
 
         if self.stop:
-            args.append("--stop")
+            args.append("-x")
 
         result = True
         for test in tests:
-            args[1] = test
+            args[0] = test
             print()
             print(
-                "Running test discovery on %s with %s processors."
-                % (test, n_processors)
+                f"Running test discovery on {test} with {self.num_processors} processors."
             )
-            # run the tests at module level i.e. my_module.tests
-            # - test must start with test/Test and must not contain the
-            #   word Mixin.
-            result &= nose.run(argv=args)
+            retcode = pytest.main(args=args)
+            result &= retcode.value == 0
         if result is False:
             exit(1)

lib/iris/tests/system_test.py

@@ -21,7 +21,7 @@
 import iris
 
 
-class SystemInitialTest(tests.IrisTest):
+class TestSystemInitial(tests.IrisTest):
     def test_supported_filetypes(self):
         nx, ny = 60, 60
         data = np.arange(nx * ny, dtype=">f4").reshape(nx, ny)

lib/iris/tests/test_constraints.py

@@ -91,7 +91,7 @@ def test_cell_different_bounds(self):
         self.assertEqual(len(sub_list), 0)
 
 
-class TestMixin:
+class ConstraintMixin:
     """
     Mix-in class for attributes & utilities common to the "normal" and "strict" test cases.
 
@@ -134,7 +134,7 @@ def setUp(self):
         self.lat_gt_45 = iris.Constraint(latitude=lambda c: c > 45)
 
 
-class RelaxedConstraintMixin(TestMixin):
+class RelaxedConstraintMixin(ConstraintMixin):
     @staticmethod
     def fixup_sigma_to_be_aux(cubes):
         # XXX Fix the cubes such that the sigma coordinate is always an AuxCoord. Pending gh issue #18
@@ -296,11 +296,11 @@ def load_match(self, files, constraints):
 
 
 @tests.skip_data
-class TestCubeExtract__names(TestMixin, tests.IrisTest):
+class TestCubeExtract__names(ConstraintMixin, tests.IrisTest):
     def setUp(self):
         fname = iris.sample_data_path("atlantic_profiles.nc")
         self.cubes = iris.load(fname)
-        TestMixin.setUp(self)
+        ConstraintMixin.setUp(self)
         cube = iris.load_cube(self.theta_path)
         # Expected names...
         self.standard_name = "air_potential_temperature"
@@ -353,11 +353,11 @@ def test_unknown(self):
 
 
 @tests.skip_data
-class TestCubeExtract__name_constraint(TestMixin, tests.IrisTest):
+class TestCubeExtract__name_constraint(ConstraintMixin, tests.IrisTest):
     def setUp(self):
         fname = iris.sample_data_path("atlantic_profiles.nc")
         self.cubes = iris.load(fname)
-        TestMixin.setUp(self)
+        ConstraintMixin.setUp(self)
         cube = iris.load_cube(self.theta_path)
         # Expected names...
         self.standard_name = "air_potential_temperature"
@@ -579,9 +579,9 @@ def test_unknown(self):
 
 
 @tests.skip_data
-class TestCubeExtract(TestMixin, tests.IrisTest):
+class TestCubeExtract(ConstraintMixin, tests.IrisTest):
     def setUp(self):
-        TestMixin.setUp(self)
+        ConstraintMixin.setUp(self)
         self.cube = iris.load_cube(self.theta_path)
 
     def test_attribute_constraint(self):
@@ -644,7 +644,7 @@ def test_non_existent_coordinate(self):
 
 
 @tests.skip_data
-class TestConstraints(TestMixin, tests.IrisTest):
+class TestConstraints(ConstraintMixin, tests.IrisTest):
     def test_constraint_expressions(self):
         rt = repr(self.theta)
         rl10 = repr(self.level_10)

requirements/ci/nox.lock/py38-linux-64.lock

@@ -1,6 +1,6 @@
 # Generated by conda-lock.
 # platform: linux-64
-# input_hash: b230293335ef7a307da7d676affe5b26d439c6c026b2db6f0a4331900ea33f02
+# input_hash: 41315fe97a24272298c496dfe62676b5ef3ce15bd4750681498f42fd4e9ea036
 @EXPLICIT
 https://conda.anaconda.org/conda-forge/linux-64/_libgcc_mutex-0.1-conda_forge.tar.bz2#d7c89558ba9fa0495403155b64376d81
 https://conda.anaconda.org/conda-forge/linux-64/ca-certificates-2021.10.8-ha878542_0.tar.bz2#575611b8a84f45960e87722eeb51fa26
@@ -112,27 +112,30 @@ https://conda.anaconda.org/conda-forge/linux-64/python-3.8.13-h582c2e5_0_cpython
 https://conda.anaconda.org/conda-forge/linux-64/xorg-libxext-1.3.4-h7f98852_1.tar.bz2#536cc5db4d0a3ba0630541aec064b5e4
 https://conda.anaconda.org/conda-forge/linux-64/xorg-libxrender-0.9.10-h7f98852_1003.tar.bz2#f59c1242cc1dd93e72c2ee2b360979eb
 https://conda.anaconda.org/conda-forge/noarch/alabaster-0.7.12-py_0.tar.bz2#2489a97287f90176ecdc3ca982b4b0a0
+https://conda.anaconda.org/conda-forge/noarch/attrs-21.4.0-pyhd8ed1ab_0.tar.bz2#f70280205d7044c8b8358c8de3190e5d
 https://conda.anaconda.org/conda-forge/noarch/cfgv-3.3.1-pyhd8ed1ab_0.tar.bz2#ebb5f5f7dc4f1a3780ef7ea7738db08c
 https://conda.anaconda.org/conda-forge/noarch/charset-normalizer-2.0.12-pyhd8ed1ab_0.tar.bz2#1f5b32dabae0f1893ae3283dac7f799e
 https://conda.anaconda.org/conda-forge/noarch/cloudpickle-2.0.0-pyhd8ed1ab_0.tar.bz2#3a8fc8b627d5fb6af827e126a10a86c6
 https://conda.anaconda.org/conda-forge/noarch/colorama-0.4.4-pyh9f0ad1d_0.tar.bz2#c08b4c1326b880ed44f3ffb04803332f
 https://conda.anaconda.org/conda-forge/linux-64/curl-7.83.0-h7bff187_0.tar.bz2#81e39fb3ae82be7e8d2dd7046f393588
 https://conda.anaconda.org/conda-forge/noarch/cycler-0.11.0-pyhd8ed1ab_0.tar.bz2#a50559fad0affdbb33729a68669ca1cb
 https://conda.anaconda.org/conda-forge/noarch/distlib-0.3.4-pyhd8ed1ab_0.tar.bz2#7b50d840543d9cdae100e91582c33035
+https://conda.anaconda.org/conda-forge/noarch/execnet-1.9.0-pyhd8ed1ab_0.tar.bz2#0e521f7a5e60d508b121d38b04874fb2
 https://conda.anaconda.org/conda-forge/noarch/filelock-3.6.0-pyhd8ed1ab_0.tar.bz2#6e03ca6c7b47a4152a2b12c6eee3bd32
 https://conda.anaconda.org/conda-forge/linux-64/fontconfig-2.14.0-h8e229c2_0.tar.bz2#f314f79031fec74adc9bff50fbaffd89
 https://conda.anaconda.org/conda-forge/noarch/fsspec-2022.3.0-pyhd8ed1ab_0.tar.bz2#960b78685ccbedb992886fc4ce37bf6e
 https://conda.anaconda.org/conda-forge/linux-64/gst-plugins-base-1.20.2-hcf0ee16_0.tar.bz2#79d7fca692d224dc29a72bda90f78a7b
 https://conda.anaconda.org/conda-forge/linux-64/hdf5-1.12.1-mpi_mpich_h08b82f9_4.tar.bz2#975d5635b158c1b3c5c795f9d0a430a1
 https://conda.anaconda.org/conda-forge/noarch/idna-3.3-pyhd8ed1ab_0.tar.bz2#40b50b8b030f5f2f22085c062ed013dd
 https://conda.anaconda.org/conda-forge/noarch/imagesize-1.3.0-pyhd8ed1ab_0.tar.bz2#be807e7606fff9436e5e700f6bffb7c6
+https://conda.anaconda.org/conda-forge/noarch/iniconfig-1.1.1-pyh9f0ad1d_0.tar.bz2#39161f81cc5e5ca45b8226fbb06c6905
 https://conda.anaconda.org/conda-forge/noarch/iris-sample-data-2.4.0-pyhd8ed1ab_0.tar.bz2#18ee9c07cf945a33f92caf1ee3d23ad9
 https://conda.anaconda.org/conda-forge/noarch/locket-1.0.0-pyhd8ed1ab_0.tar.bz2#91e27ef3d05cc772ce627e51cff111c4
 https://conda.anaconda.org/conda-forge/noarch/munkres-1.1.4-pyh9f0ad1d_0.tar.bz2#2ba8498c1018c1e9c61eb99b973dfe19
-https://conda.anaconda.org/conda-forge/noarch/nose-1.3.7-py_1006.tar.bz2#382019d5f8e9362ef6f60a8d4e7bce8f
 https://conda.anaconda.org/conda-forge/noarch/olefile-0.46-pyh9f0ad1d_1.tar.bz2#0b2e68acc8c78c8cc392b90983481f58
 https://conda.anaconda.org/conda-forge/noarch/platformdirs-2.5.1-pyhd8ed1ab_0.tar.bz2#d5df87964a39f67c46a5448f4e78d9b6
 https://conda.anaconda.org/conda-forge/linux-64/proj-9.0.0-h93bde94_1.tar.bz2#cf908994f24ea526afc59f295d5b07c1
+https://conda.anaconda.org/conda-forge/noarch/py-1.11.0-pyh6c4a22f_0.tar.bz2#b4613d7e7a493916d867842a6a148054
 https://conda.anaconda.org/conda-forge/noarch/pycparser-2.21-pyhd8ed1ab_0.tar.bz2#076becd9e05608f8dc72757d5f3a91ff
 https://conda.anaconda.org/conda-forge/noarch/pyparsing-3.0.8-pyhd8ed1ab_0.tar.bz2#7f5738c49fdccd0fc755bfd25a5ea66c
 https://conda.anaconda.org/conda-forge/noarch/pyshp-2.3.0-pyhd8ed1ab_0.tar.bz2#0158f62cae46ad1fb77c522c4e7ecc90
@@ -148,6 +151,7 @@ https://conda.anaconda.org/conda-forge/noarch/sphinxcontrib-jsmath-1.0.1-py_0.ta
 https://conda.anaconda.org/conda-forge/noarch/sphinxcontrib-qthelp-1.0.3-py_0.tar.bz2#d01180388e6d1838c3e1ad029590aa7a
 https://conda.anaconda.org/conda-forge/noarch/sphinxcontrib-serializinghtml-1.1.5-pyhd8ed1ab_2.tar.bz2#9ff55a0901cf952f05c654394de76bf7
 https://conda.anaconda.org/conda-forge/noarch/toml-0.10.2-pyhd8ed1ab_0.tar.bz2#f832c45a477c78bebd107098db465095
+https://conda.anaconda.org/conda-forge/noarch/tomli-2.0.1-pyhd8ed1ab_0.tar.bz2#5844808ffab9ebdb694585b50ba02a96
 https://conda.anaconda.org/conda-forge/noarch/toolz-0.11.2-pyhd8ed1ab_0.tar.bz2#f348d1590550371edfac5ed3c1d44f7e
 https://conda.anaconda.org/conda-forge/noarch/wheel-0.37.1-pyhd8ed1ab_0.tar.bz2#1ca02aaf78d9c70d9a81a3bed5752022
 https://conda.anaconda.org/conda-forge/noarch/zipp-3.8.0-pyhd8ed1ab_0.tar.bz2#050b94cf4a8c760656e51d2d44e4632c
@@ -168,7 +172,9 @@ https://conda.anaconda.org/conda-forge/linux-64/numpy-1.22.3-py38h99721a1_2.tar.
 https://conda.anaconda.org/conda-forge/noarch/packaging-21.3-pyhd8ed1ab_0.tar.bz2#71f1ab2de48613876becddd496371c85
 https://conda.anaconda.org/conda-forge/noarch/partd-1.2.0-pyhd8ed1ab_0.tar.bz2#0c32f563d7f22e3a34c95cad8cc95651
 https://conda.anaconda.org/conda-forge/linux-64/pillow-6.2.2-py38h9776b28_0.tar.bz2#bd527d652ba06fb2aae61640bcf7c435
+https://conda.anaconda.org/conda-forge/linux-64/pluggy-1.0.0-py38h578d9bd_3.tar.bz2#6ce4ce3d4490a56eb33b52c179609193
 https://conda.anaconda.org/conda-forge/noarch/pockets-0.9.1-py_0.tar.bz2#1b52f0c42e8077e5a33e00fe72269364
+https://conda.anaconda.org/conda-forge/linux-64/psutil-5.9.0-py38h0a891b7_1.tar.bz2#92045570d1da14b3f90621c54f8afb12
 https://conda.anaconda.org/conda-forge/linux-64/pyqt5-sip-4.19.18-py38h709712a_8.tar.bz2#11b72f5b1cc15427c89232321172a0bc
 https://conda.anaconda.org/conda-forge/linux-64/pysocks-1.7.1-py38h578d9bd_5.tar.bz2#11113c7e50bb81f30762fe8325f305e1
 https://conda.anaconda.org/conda-forge/noarch/python-dateutil-2.8.2-pyhd8ed1ab_0.tar.bz2#dd999d1cc9f79e67dbb855c8924c7984
@@ -194,6 +200,7 @@ https://conda.anaconda.org/conda-forge/noarch/pip-22.0.4-pyhd8ed1ab_0.tar.bz2#b1
 https://conda.anaconda.org/conda-forge/noarch/pygments-2.12.0-pyhd8ed1ab_0.tar.bz2#cb27e2ded147e5bcc7eafc1c6d343cb3
 https://conda.anaconda.org/conda-forge/linux-64/pyproj-3.3.1-py38h5b5ac8f_0.tar.bz2#5d91e0c583547eb69345c3acf4d753ee
 https://conda.anaconda.org/conda-forge/linux-64/pyqt-impl-5.12.3-py38h0ffb2e6_8.tar.bz2#acfc7625a212c27f7decdca86fdb2aba
+https://conda.anaconda.org/conda-forge/linux-64/pytest-7.1.2-py38h578d9bd_0.tar.bz2#626d2b8f96c8c3d20198e6bd84d1cfb7
 https://conda.anaconda.org/conda-forge/linux-64/python-stratify-0.2.post0-py38h71d37f0_2.tar.bz2#cdef2f7b0e263e338016da4b77ae4c0b
 https://conda.anaconda.org/conda-forge/linux-64/pywavelets-1.3.0-py38h71d37f0_1.tar.bz2#704f1776af689de568514b0ff9dd0fbe
 https://conda.anaconda.org/conda-forge/linux-64/scipy-1.8.0-py38h56a6a73_1.tar.bz2#86073932d9e675c5929376f6f8b79b97
@@ -210,13 +217,15 @@ https://conda.anaconda.org/conda-forge/linux-64/pango-1.50.7-hbd2fdc8_0.tar.bz2#
 https://conda.anaconda.org/conda-forge/noarch/pyopenssl-22.0.0-pyhd8ed1ab_0.tar.bz2#1d7e241dfaf5475e893d4b824bb71b44
 https://conda.anaconda.org/conda-forge/linux-64/pyqtchart-5.12-py38h7400c14_8.tar.bz2#78a2a6cb4ef31f997c1bee8223a9e579
 https://conda.anaconda.org/conda-forge/linux-64/pyqtwebengine-5.12.1-py38h7400c14_8.tar.bz2#857894ea9c5e53c962c3a0932efa71ea
+https://conda.anaconda.org/conda-forge/noarch/pytest-forked-1.4.0-pyhd8ed1ab_0.tar.bz2#95286e05a617de9ebfe3246cecbfb72f
 https://conda.anaconda.org/conda-forge/linux-64/cartopy-0.20.2-py38h51d8e34_4.tar.bz2#9f23c80d08456c02ab284f974719b013
 https://conda.anaconda.org/conda-forge/linux-64/esmpy-8.2.0-mpi_mpich_py38h9147699_101.tar.bz2#5a9de1dec507b6614150a77d1aabf257
 https://conda.anaconda.org/conda-forge/linux-64/gtk2-2.24.33-h90689f9_2.tar.bz2#957a0255ab58aaf394a91725d73ab422
 https://conda.anaconda.org/conda-forge/linux-64/librsvg-2.52.5-h0a9e6e8_3.tar.bz2#a08562889b985d021550e22443cf0fce
 https://conda.anaconda.org/conda-forge/noarch/nc-time-axis-1.4.1-pyhd8ed1ab_0.tar.bz2#281b58948bf60a2582de9e548bcc5369
 https://conda.anaconda.org/conda-forge/linux-64/pre-commit-2.19.0-py38h578d9bd_0.tar.bz2#aa6a241a741c27c9560fd3cebb3f43ce
 https://conda.anaconda.org/conda-forge/linux-64/pyqt-5.12.3-py38h578d9bd_8.tar.bz2#88368a5889f31dff922a2d57bbfc3f5b
+https://conda.anaconda.org/conda-forge/noarch/pytest-xdist-2.5.0-pyhd8ed1ab_0.tar.bz2#1fdd1f3baccf0deb647385c677a1a48e
 https://conda.anaconda.org/conda-forge/noarch/urllib3-1.26.9-pyhd8ed1ab_0.tar.bz2#0ea179ee251aa7100807c35bc0252693
 https://conda.anaconda.org/conda-forge/linux-64/graphviz-3.0.0-h5abf519_1.tar.bz2#fcaf13b2713335ff871ba551d5bda679
 https://conda.anaconda.org/conda-forge/linux-64/matplotlib-3.5.2-py38h578d9bd_0.tar.bz2#b15039e7f67b5f91c35f9b6d27c2775c

requirements/ci/py38.yml

@@ -34,9 +34,11 @@ dependencies:
 # Test dependencies.
   - filelock
   - imagehash >=4.0
-  - nose
   - pillow <7
   - pre-commit
+  - psutil
+  - pytest
+  - pytest-xdist
   - requests
 
 # Documentation dependencies.

setup.cfg

@@ -75,10 +75,11 @@ docs =
 test =
     filelock
     imagehash>=4.0
-    nose
     pillow<7
     pre-commit
     requests
+    pytest
+    pytest-xdist
 all =
     mo_pack
     nc-time-axis>=1.4