Try to detect borked package installations. (#12244)

* Try to detect borked package installations.

Fixes #12223.

Co-authored-by: Sean Quah <8349537+squahtx@users.noreply.github.com>

1 files changed, 14 insertions, 1 deletions

diff --git a/tests/util/test_check_dependencies.py b/tests/util/test_check_dependencies.py

index 38e9f58ac6..5d1aa025d1 100644
--- a/tests/util/test_check_dependencies.py
+++ b/tests/util/test_check_dependencies.py
@@ -12,7 +12,7 @@ from tests.unittest import TestCase
 
 
 class DummyDistribution(metadata.Distribution):
-    def __init__(self, version: str):
+    def __init__(self, version: object):
         self._version = version
 
     @property
@@ -30,6 +30,7 @@ old = DummyDistribution("0.1.2")
 old_release_candidate = DummyDistribution("0.1.2rc3")
 new = DummyDistribution("1.2.3")
 new_release_candidate = DummyDistribution("1.2.3rc4")
+distribution_with_no_version = DummyDistribution(None)
 
 # could probably use stdlib TestCase --- no need for twisted here
 
@@ -67,6 +68,18 @@ class TestDependencyChecker(TestCase):
                 # should not raise
                 check_requirements()
 
+    def test_version_reported_as_none(self) -> None:
+        """Complain if importlib.metadata.version() returns None.
+
+        This shouldn't normally happen, but it was seen in the wild (#12223).
+        """
+        with patch(
+            "synapse.util.check_dependencies.metadata.requires",
+            return_value=["dummypkg >= 1"],
+        ):
+            with self.mock_installed_package(distribution_with_no_version):
+                self.assertRaises(DependencyException, check_requirements)
+
     def test_checks_ignore_dev_dependencies(self) -> None:
         """Bot generic and per-extra checks should ignore dev dependencies."""
         with patch(