def test_consider_env_plugin_instantiation(self, testdir, monkeypatch): pluginmanager = PluginManager() testdir.syspathinsert() testdir.makepyfile(xy123="#") monkeypatch.setitem(os.environ, 'PYTEST_PLUGINS', 'xy123') l1 = len(pluginmanager.getplugins()) pluginmanager.consider_env() l2 = len(pluginmanager.getplugins()) assert l2 == l1 + 1 assert pluginmanager.getplugin('xy123') pluginmanager.consider_env() l3 = len(pluginmanager.getplugins()) assert l2 == l3