Streamline the test to check one expectation (the standard dist-info …

…expectation is handled by other tests above.

tests/test_main.py

@@ -401,29 +401,15 @@ def test_packages_distributions_all_module_types(self):
 
 
 class PackagesDistributionsDistTest(
-    fixtures.DistInfoPkg,
     fixtures.DistInfoSymlinkedPkg,
     unittest.TestCase,
 ):
-    def test_packages_distributions_on_dist_info(self):
+    def test_packages_distributions_symlinked_top_level(self):
         """
-        Test _top_level_inferred() on various dist-info packages.
+        Distribution is resolvable from a simple top-level symlink in RECORD.
+        See #452.
         """
-        distributions = packages_distributions()
-
-        def import_names_from_package(package_name):
-            return {
-                import_name
-                for import_name, package_names in distributions.items()
-                if package_name in package_names
-            }
-
-        # distinfo-pkg has one import ('mod') inferred from RECORD
-        assert import_names_from_package('distinfo-pkg') == {'mod'}
-
-        # symlinked-pkg has one import ('symlinked') inderred from RECORD which
-        # references a symlink to the real package dir elsewhere.
-        assert import_names_from_package('symlinked-pkg') == {'symlinked'}
+        assert packages_distributions()['symlinked'] == ['symlinked-pkg']
 
 
 class PackagesDistributionsEggTest(