conftest: introduce disable_subp_usage autouse fixture (#304)

This mirrors the behaviour of CiTestCase.allowed_subp, by causing all
calls to util.subp to raise an AssertionError.

1 files changed, 18 insertions, 0 deletions

diff --git a/cloudinit/tests/test_conftest.py b/cloudinit/tests/test_conftest.py
new file mode 100644
index 00000000..62a5361d
--- /dev/null
+++ b/cloudinit/tests/test_conftest.py
@@ -0,0 +1,18 @@
+import pytest
+
+from cloudinit import util
+
+
+class TestDisableSubpUsage:
+
+    def test_using_subp_raises_assertion_error(self):
+        with pytest.raises(AssertionError):
+            util.subp(["some", "args"])
+
+    def test_typeerrors_on_incorrect_usage(self):
+        with pytest.raises(TypeError):
+            util.subp()
+
+    @pytest.mark.parametrize('disable_subp_usage', [False], indirect=True)
+    def test_subp_usage_can_be_reenabled(self):
+        util.subp(['whoami'])