add test__core_watcher.py

greentest/test__core_watcher.py

+import sys
+import gevent
+import unittest
+
+
+class Test(unittest.TestCase):
+
+    def test_types(self):
+        loop = gevent.core.loop()
+        lst = []
+
+        io = loop.timer(0.01)
+
+        # test that cannot pass non-callable thing to start()
+        self.assertRaises(TypeError, io.start, None)
+        self.assertRaises(TypeError, io.start, 5)
+        # test that cannot set 'callback' to non-callable thing later either
+        io.start(lambda *args: lst.append(args))
+        self.assertEqual(io.args, ())
+        try:
+            io.callback = None
+            raise AssertionError('"io.callback = None" must raise TypeError')
+        except TypeError:
+            pass
+        try:
+            io.callback = 5
+            raise AssertionError('"io.callback = 5" must raise TypeError')
+        except TypeError:
+            pass
+        # test that args can be changed later
+        io.args = (1, 2, 3)
+        # test that only tuple and None are accepted by 'args' attribute
+        try:
+            io.args = 5
+            raise AssertionError('"io.args = 5" must raise TypeError')
+        except TypeError:
+            pass
+        self.assertEqual(io.args, (1, 2, 3))
+        try:
+            io.args = [4, 5]
+            raise AssertionError('"io.args = [4, 5]" must raise TypeError')
+        except TypeError:
+            pass
+        self.assertEqual(io.args, (1, 2, 3))
+        # None also works, means empty tuple
+        io.args = None
+        loop.run()
+        self.assertEqual(lst, [()])
+
+
+if __name__ == '__main__':
+    unittest.main()