Reorganize unit test locations under tests/unittests (#1126)

This attempts to standardize unit test file location under test/unittests/
such that any source file located at cloudinit/path/to/file.py may have a
corresponding unit test file at test/unittests/path/to/test_file.py.

Noteworthy Comments:
====================
Four different duplicate test files existed:
test_{gpg,util,cc_mounts,cc_resolv_conf}.py
Each of these duplicate file pairs has been merged together. This is a
break in git history for these files.

The test suite appears to have a dependency on test order. Changing test
order causes some tests to fail. This should be rectified, but for now
some tests have been modified in
tests/unittests/config/test_set_passwords.py.

A helper class name starts with "Test" which causes pytest to try
executing it as a test case, which then throws warnings "due to Class
having __init__()".  Silence by changing the name of the class.

# helpers.py is imported in many test files, import paths change
cloudinit/tests/helpers.py -> tests/unittests/helpers.py

# Move directories:
cloudinit/distros/tests -> tests/unittests/distros
cloudinit/cmd/devel/tests -> tests/unittests/cmd/devel
cloudinit/cmd/tests -> tests/unittests/cmd/
cloudinit/sources/helpers/tests -> tests/unittests/sources/helpers
cloudinit/sources/tests -> tests/unittests/sources
cloudinit/net/tests -> tests/unittests/net
cloudinit/config/tests -> tests/unittests/config
cloudinit/analyze/tests/ -> tests/unittests/analyze/

# Standardize tests already in tests/unittests/
test_datasource -> sources
test_distros -> distros
test_vmware -> sources/vmware
test_handler -> config        # this contains cloudconfig module tests
test_runs -> runs

1 files changed, 60 insertions, 0 deletions

diff --git a/tests/unittests/test_features.py b/tests/unittests/test_features.py
new file mode 100644
index 00000000..d7a7226d
--- /dev/null
+++ b/tests/unittests/test_features.py
@@ -0,0 +1,60 @@
+# This file is part of cloud-init. See LICENSE file for license information.
+# pylint: disable=no-member,no-name-in-module
+"""
+This file is for testing the feature flag functionality itself,
+NOT for testing any individual feature flag
+"""
+import pytest
+import sys
+from pathlib import Path
+
+import cloudinit
+
+
+@pytest.yield_fixture()
+def create_override(request):
+    """
+    Create a feature overrides file and do some module wizardry to make
+    it seem like we're importing the features file for the first time.
+
+    After creating the override file with the values passed by the test,
+    we need to reload cloudinit.features
+    to get all of the current features (including the overridden ones).
+    Once the test is complete, we remove the file we created and set
+    features and feature_overrides modules to how they were before
+    the test started
+    """
+    override_path = Path(cloudinit.__file__).parent / 'feature_overrides.py'
+    if override_path.exists():
+        raise Exception("feature_overrides.py unexpectedly exists! "
+                        "Remove it to run this test.")
+    with override_path.open('w') as f:
+        for key, value in request.param.items():
+            f.write('{} = {}\n'.format(key, value))
+
+    sys.modules.pop('cloudinit.features', None)
+
+    yield
+
+    override_path.unlink()
+    sys.modules.pop('cloudinit.feature_overrides', None)
+
+
+class TestFeatures:
+    def test_feature_without_override(self):
+        from cloudinit.features import ERROR_ON_USER_DATA_FAILURE
+        assert ERROR_ON_USER_DATA_FAILURE is True
+
+    @pytest.mark.parametrize('create_override',
+                             [{'ERROR_ON_USER_DATA_FAILURE': False}],
+                             indirect=True)
+    def test_feature_with_override(self, create_override):
+        from cloudinit.features import ERROR_ON_USER_DATA_FAILURE
+        assert ERROR_ON_USER_DATA_FAILURE is False
+
+    @pytest.mark.parametrize('create_override',
+                             [{'SPAM': True}],
+                             indirect=True)
+    def test_feature_only_in_override(self, create_override):
+        from cloudinit.features import SPAM
+        assert SPAM is True