Only skip unit test on MacOS and only on Github Actions (#38)

This commit Closes #35.

We still don't know why the unit test `test_laplacian_embedding_elbowcut_none` fails on the MacOS Github Action instances, but not on any other MacOS system that we've tried.

This fix addresses the issue by effectively ignoring it as we can't reproduce it elsewhere, but it took steps to make the test be skipped only on Github Actions, only when using the .github/workflows/validate_on_push.yml workflow file, and only as long as the SKIP_TEST_35=true environment variable is used when running the test.

This means that developer/user testers of topologic with MacOS will still run this unit test, and we can also create a new branch to disable this flag and continue testing topologic + Github Actions on MacOS in an attempt to see when, or if, this is fixed (since it doesn't seem to be related to us so much as Github's CI instances).

Co-authored-by: Dwayne Pryce <dwpryce@microsoft.com>

.github/workflows/publish.yml

@@ -36,7 +36,9 @@ jobs:
         flake8 ./topologic ./tests --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics
     - name: Test with pytest
       run: |
-        pytest tests topologic --doctest-modules
+        pytest -v tests topologic --doctest-modules
+      env:
+        SKIP_TEST_35: true
     - name: Generate docs with Sphinx
       run: |
         sphinx-build -W -a docs/ docs/_build/html

.github/workflows/validate_on_push.yml

@@ -34,7 +34,9 @@ jobs:
         flake8 ./topologic ./tests --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics
     - name: Test with pytest
       run: |
-        pytest tests topologic --doctest-modules
+        pytest -v tests topologic --doctest-modules
+      env:
+        SKIP_TEST_35: true
     - name: Build with setuptools
       run: |
         python setup.py build sdist

tests/embedding/test_laplacian_spectral_embedding.py

@@ -2,12 +2,12 @@
 # Licensed under the MIT license.
 
 import pickle
+import os
 import sys
 import unittest
 
 import networkx as nx
 import numpy as np
-import pytest
 
 from topologic.embedding import laplacian_embedding
 
@@ -32,10 +32,11 @@ def test_laplacian_embedding(self):
         np.testing.assert_allclose(expected_matrix, matrix, rtol=1e-5)
         self.assertListEqual(expected_label, labels)
 
+    @unittest.skipIf(
+        sys.platform.startswith('darwin') and os.getenv("SKIP_TEST_35", "false") == "true",
+        "Test not supported on MacOS Github Actions, see: https://github.com/microsoft/topologic/issues/35"
+    )
     def test_laplacian_embedding_elbowcut_none(self):
-        if sys.platform.startswith('darwin'):
-            pytest.skip('Test not supported on Mac OS')
-
         graph = nx.Graph([('a', 'b', {'weight': 2.0}), ('b', 'c', {'weight': 2.0})])
         result = laplacian_embedding(
             graph,