Remove hook proxy cache

Fix #2016

testing/test_conftest.py

@@ -423,3 +423,28 @@ def test_conftest_exception_handling(testdir):
     res = testdir.runpytest()
     assert res.ret == 4
     assert 'raise ValueError()' in [line.strip() for line in res.errlines]
+
+
+def test_hook_proxy(testdir):
+    """Session's gethookproxy() would cache conftests incorrectly (#2016).
+    It was decided to remove the cache altogether.
+    """
+    testdir.makepyfile(**{
+        'root/demo-0/test_foo1.py': "def test1(): pass",
+
+        'root/demo-a/test_foo2.py': "def test1(): pass",
+        'root/demo-a/conftest.py': """
+            def pytest_ignore_collect(path, config):
+                return True
+            """,
+
+        'root/demo-b/test_foo3.py': "def test1(): pass",
+        'root/demo-c/test_foo4.py': "def test1(): pass",
+    })
+    result = testdir.runpytest()
+    result.stdout.fnmatch_lines([
+        '*test_foo1.py*',
+        '*test_foo3.py*',
+        '*test_foo4.py*',
+        '*3 passed*',
+    ])

testing/test_pluginmanager.py

@@ -4,7 +4,8 @@ import py
 import os
 
 from _pytest.config import get_config, PytestPluginManager
-from _pytest.main import EXIT_NOTESTSCOLLECTED
+from _pytest.main import EXIT_NOTESTSCOLLECTED, Session
+
 
 @pytest.fixture
 def pytestpm():
@@ -133,6 +134,25 @@ class TestPytestPluginInteractions:
         finally:
             undo()
 
+    def test_hook_proxy(self, testdir):
+        """Test the gethookproxy function(#2016)"""
+        config = testdir.parseconfig()
+        session = Session(config)
+        testdir.makepyfile(**{
+            'tests/conftest.py': '',
+            'tests/subdir/conftest.py': '',
+        })
+
+        conftest1 = testdir.tmpdir.join('tests/conftest.py')
+        conftest2 = testdir.tmpdir.join('tests/subdir/conftest.py')
+
+        config.pluginmanager._importconftest(conftest1)
+        ihook_a = session.gethookproxy(testdir.tmpdir.join('tests'))
+        assert ihook_a is not None
+        config.pluginmanager._importconftest(conftest2)
+        ihook_b = session.gethookproxy(testdir.tmpdir.join('tests'))
+        assert ihook_a is not ihook_b
+
     def test_warn_on_deprecated_multicall(self, pytestpm):
         warnings = []