Issue #19607: Use specific asserts in weakref tests.

Lib/test/test_weakref.py

@@ -97,11 +97,9 @@ def test_multiple_callbacks(self):
         ref1 = weakref.ref(o, self.callback)
         ref2 = weakref.ref(o, self.callback)
         del o
-        self.assertTrue(ref1() is None,
+        self.assertIsNone(ref1(), "expected reference to be invalidated")
-                     "expected reference to be invalidated")
+        self.assertIsNone(ref2(), "expected reference to be invalidated")
-        self.assertTrue(ref2() is None,
+        self.assertEqual(self.cbcalled, 2,
-                     "expected reference to be invalidated")
-        self.assertTrue(self.cbcalled == 2,
                      "callback not called the right number of times")
 
     def test_multiple_selfref_callbacks(self):
@@ -140,10 +138,10 @@ def check(proxy):
     def check_basic_ref(self, factory):
         o = factory()
         ref = weakref.ref(o)
-        self.assertTrue(ref() is not None,
+        self.assertIsNotNone(ref(),
                      "weak reference to live object should be live")
         o2 = ref()
-        self.assertTrue(o is o2,
+        self.assertIs(o, o2,
                      "<ref>() should return original object if live")
 
     def check_basic_callback(self, factory):
@@ -151,9 +149,9 @@ def check_basic_callback(self, factory):
         o = factory()
         ref = weakref.ref(o, self.callback)
         del o
-        self.assertTrue(self.cbcalled == 1,
+        self.assertEqual(self.cbcalled, 1,
                      "callback did not properly set 'cbcalled'")
-        self.assertTrue(ref() is None,
+        self.assertIsNone(ref(),
                      "ref2 should be dead after deleting object reference")
 
     def test_ref_reuse(self):
@@ -163,19 +161,19 @@ def test_ref_reuse(self):
         # between these two; it should make no difference
         proxy = weakref.proxy(o)
         ref2 = weakref.ref(o)
-        self.assertTrue(ref1 is ref2,
+        self.assertIs(ref1, ref2,
                      "reference object w/out callback should be re-used")
 
         o = C()
         proxy = weakref.proxy(o)
         ref1 = weakref.ref(o)
         ref2 = weakref.ref(o)
-        self.assertTrue(ref1 is ref2,
+        self.assertIs(ref1, ref2,
                      "reference object w/out callback should be re-used")
-        self.assertTrue(weakref.getweakrefcount(o) == 2,
+        self.assertEqual(weakref.getweakrefcount(o), 2,
                      "wrong weak ref count for object")
         del proxy
-        self.assertTrue(weakref.getweakrefcount(o) == 1,
+        self.assertEqual(weakref.getweakrefcount(o), 1,
                      "wrong weak ref count for object after deleting proxy")
 
     def test_proxy_reuse(self):
@@ -183,7 +181,7 @@ def test_proxy_reuse(self):
         proxy1 = weakref.proxy(o)
         ref = weakref.ref(o)
         proxy2 = weakref.proxy(o)
-        self.assertTrue(proxy1 is proxy2,
+        self.assertIs(proxy1, proxy2,
                      "proxy object w/out callback should have been re-used")
 
     def test_basic_proxy(self):
@@ -263,19 +261,19 @@ def check_shared_without_callback(self, makeref):
         o = Object(1)
         p1 = makeref(o, None)
         p2 = makeref(o, None)
-        self.assertTrue(p1 is p2, "both callbacks were None in the C API")
+        self.assertIs(p1, p2, "both callbacks were None in the C API")
         del p1, p2
         p1 = makeref(o)
         p2 = makeref(o, None)
-        self.assertTrue(p1 is p2, "callbacks were NULL, None in the C API")
+        self.assertIs(p1, p2, "callbacks were NULL, None in the C API")
         del p1, p2
         p1 = makeref(o)
         p2 = makeref(o)
-        self.assertTrue(p1 is p2, "both callbacks were NULL in the C API")
+        self.assertIs(p1, p2, "both callbacks were NULL in the C API")
         del p1, p2
         p1 = makeref(o, None)
         p2 = makeref(o)
-        self.assertTrue(p1 is p2, "callbacks were None, NULL in the C API")
+        self.assertIs(p1, p2, "callbacks were None, NULL in the C API")
 
     def test_callable_proxy(self):
         o = Callable()
@@ -283,13 +281,13 @@ def test_callable_proxy(self):
 
         self.check_proxy(o, ref1)
 
-        self.assertTrue(type(ref1) is weakref.CallableProxyType,
+        self.assertIs(type(ref1), weakref.CallableProxyType,
                      "proxy is not of callable type")
         ref1('twinkies!')
-        self.assertTrue(o.bar == 'twinkies!',
+        self.assertEqual(o.bar, 'twinkies!',
                      "call through proxy not passed through to original")
         ref1(x='Splat.')
-        self.assertTrue(o.bar == 'Splat.',
+        self.assertEqual(o.bar, 'Splat.',
                      "call through proxy not passed through to original")
 
         # expect due to too few args
@@ -300,24 +298,23 @@ def test_callable_proxy(self):
 
     def check_proxy(self, o, proxy):
         o.foo = 1
-        self.assertTrue(proxy.foo == 1,
+        self.assertEqual(proxy.foo, 1,
                      "proxy does not reflect attribute addition")
         o.foo = 2
-        self.assertTrue(proxy.foo == 2,
+        self.assertEqual(proxy.foo, 2,
                      "proxy does not reflect attribute modification")
         del o.foo
-        self.assertTrue(not hasattr(proxy, 'foo'),
+        self.assertFalse(hasattr(proxy, 'foo'),
                      "proxy does not reflect attribute removal")
 
         proxy.foo = 1
-        self.assertTrue(o.foo == 1,
+        self.assertEqual(o.foo, 1,
                      "object does not reflect attribute addition via proxy")
         proxy.foo = 2
-        self.assertTrue(
+        self.assertEqual(o.foo, 2,
-            o.foo == 2,
             "object does not reflect attribute modification via proxy")
         del proxy.foo
-        self.assertTrue(not hasattr(o, 'foo'),
+        self.assertFalse(hasattr(o, 'foo'),
                      "object does not reflect attribute removal via proxy")
 
     def test_proxy_deletion(self):
@@ -341,21 +338,21 @@ def test_getweakrefcount(self):
         o = C()
         ref1 = weakref.ref(o)
         ref2 = weakref.ref(o, self.callback)
-        self.assertTrue(weakref.getweakrefcount(o) == 2,
+        self.assertEqual(weakref.getweakrefcount(o), 2,
                      "got wrong number of weak reference objects")
 
         proxy1 = weakref.proxy(o)
         proxy2 = weakref.proxy(o, self.callback)
-        self.assertTrue(weakref.getweakrefcount(o) == 4,
+        self.assertEqual(weakref.getweakrefcount(o), 4,
                      "got wrong number of weak reference objects")
 
         del ref1, ref2, proxy1, proxy2
-        self.assertTrue(weakref.getweakrefcount(o) == 0,
+        self.assertEqual(weakref.getweakrefcount(o), 0,
                      "weak reference objects not unlinked from"
                      " referent when discarded.")
 
         # assumes ints do not support weakrefs
-        self.assertTrue(weakref.getweakrefcount(1) == 0,
+        self.assertEqual(weakref.getweakrefcount(1), 0,
                      "got wrong number of weak reference objects for int")
 
     def test_getweakrefs(self):
@@ -363,22 +360,22 @@ def test_getweakrefs(self):
         ref1 = weakref.ref(o, self.callback)
         ref2 = weakref.ref(o, self.callback)
         del ref1
-        self.assertTrue(weakref.getweakrefs(o) == [ref2],
+        self.assertEqual(weakref.getweakrefs(o), [ref2],
                      "list of refs does not match")
 
         o = C()
         ref1 = weakref.ref(o, self.callback)
         ref2 = weakref.ref(o, self.callback)
         del ref2
-        self.assertTrue(weakref.getweakrefs(o) == [ref1],
+        self.assertEqual(weakref.getweakrefs(o), [ref1],
                      "list of refs does not match")
 
         del ref1
-        self.assertTrue(weakref.getweakrefs(o) == [],
+        self.assertEqual(weakref.getweakrefs(o), [],
                      "list of refs not cleared")
 
         # assumes ints do not support weakrefs
-        self.assertTrue(weakref.getweakrefs(1) == [],
+        self.assertEqual(weakref.getweakrefs(1), [],
                      "list of refs does not match for int")
 
     def test_newstyle_number_ops(self):
@@ -386,8 +383,8 @@ class F(float):
             pass
         f = F(2.0)
         p = weakref.proxy(f)
-        self.assertTrue(p + 1.0 == 3.0)
+        self.assertEqual(p + 1.0, 3.0)
-        self.assertTrue(1.0 + p == 3.0)  # this used to SEGV
+        self.assertEqual(1.0 + p, 3.0)  # this used to SEGV
 
     def test_callbacks_protected(self):
         # Callbacks protected from already-set exceptions?
@@ -640,7 +637,7 @@ def cb(self, ignore):
         c.wr = weakref.ref(d, callback)     # this won't trigger
         d.wr = weakref.ref(callback, d.cb)  # ditto
         external_wr = weakref.ref(callback, safe_callback)  # but this will
-        self.assertTrue(external_wr() is callback)
+        self.assertIs(external_wr(), callback)
 
         # The weakrefs attached to c and d should get cleared, so that
         # C.cb is never called.  But external_wr isn't part of the cyclic
@@ -843,11 +840,11 @@ def __call__(self):
                 return super().__call__()
         o = Object("foo")
         mr = MyRef(o, value=24)
-        self.assertTrue(mr() is o)
+        self.assertIs(mr(), o)
         self.assertTrue(mr.called)
         self.assertEqual(mr.value, 24)
         del o
-        self.assertTrue(mr() is None)
+        self.assertIsNone(mr())
         self.assertTrue(mr.called)
 
     def test_subclass_refs_dont_replace_standard_refs(self):
@@ -856,14 +853,14 @@ class MyRef(weakref.ref):
         o = Object(42)
         r1 = MyRef(o)
         r2 = weakref.ref(o)
-        self.assertTrue(r1 is not r2)
+        self.assertIsNot(r1, r2)
         self.assertEqual(weakref.getweakrefs(o), [r2, r1])
         self.assertEqual(weakref.getweakrefcount(o), 2)
         r3 = MyRef(o)
         self.assertEqual(weakref.getweakrefcount(o), 3)
         refs = weakref.getweakrefs(o)
         self.assertEqual(len(refs), 3)
-        self.assertTrue(r2 is refs[0])
+        self.assertIs(r2, refs[0])
         self.assertIn(r1, refs[1:])
         self.assertIn(r3, refs[1:])
 
@@ -873,7 +870,7 @@ class MyRef(weakref.ref):
         o = Object(42)
         r1 = MyRef(o, id)
         r2 = MyRef(o, str)
-        self.assertTrue(r1 is not r2)
+        self.assertIsNot(r1, r2)
         refs = weakref.getweakrefs(o)
         self.assertIn(r1, refs)
         self.assertIn(r2, refs)
@@ -1135,7 +1132,7 @@ def test_weak_values(self):
         dict, objects = self.make_weak_valued_dict()
         for o in objects:
             self.assertEqual(weakref.getweakrefcount(o), 1)
-            self.assertTrue(o is dict[o.arg],
+            self.assertIs(o, dict[o.arg],
                          "wrong object returned by weak dict!")
         items1 = list(dict.items())
         items2 = list(dict.copy().items())
@@ -1164,9 +1161,9 @@ def test_weak_keys(self):
         #
         dict, objects = self.make_weak_keyed_dict()
         for o in objects:
-            self.assertTrue(weakref.getweakrefcount(o) == 1,
+            self.assertEqual(weakref.getweakrefcount(o), 1,
                          "wrong number of weak references to %r!" % o)
-            self.assertTrue(o.arg is dict[o],
+            self.assertIs(o.arg, dict[o],
                          "wrong object returned by weak dict!")
         items1 = dict.items()
         items2 = dict.copy().items()
@@ -1175,10 +1172,10 @@ def test_weak_keys(self):
         del items1, items2
         self.assertEqual(len(dict), self.COUNT)
         del objects[0]
-        self.assertTrue(len(dict) == (self.COUNT - 1),
+        self.assertEqual(len(dict), (self.COUNT - 1),
                      "deleting object did not cause dictionary update")
         del objects, o
-        self.assertTrue(len(dict) == 0,
+        self.assertEqual(len(dict), 0,
                      "deleting the keys did not clear the dictionary")
         o = Object(42)
         dict[o] = "What is the meaning of the universe?"
@@ -1388,15 +1385,15 @@ def check_popitem(self, klass, key1, value1, key2, value2):
         k, v = weakdict.popitem()
         self.assertEqual(len(weakdict), 1)
         if k is key1:
-            self.assertTrue(v is value1)
+            self.assertIs(v, value1)
         else:
-            self.assertTrue(v is value2)
+            self.assertIs(v, value2)
         k, v = weakdict.popitem()
         self.assertEqual(len(weakdict), 0)
         if k is key1:
-            self.assertTrue(v is value1)
+            self.assertIs(v, value1)
         else:
-            self.assertTrue(v is value2)
+            self.assertIs(v, value2)
 
     def test_weak_valued_dict_popitem(self):
         self.check_popitem(weakref.WeakValueDictionary,
@@ -1407,21 +1404,21 @@ def test_weak_keyed_dict_popitem(self):
                            C(), "value 1", C(), "value 2")
 
     def check_setdefault(self, klass, key, value1, value2):
-        self.assertTrue(value1 is not value2,
+        self.assertIsNot(value1, value2,
                      "invalid test"
                      " -- value parameters must be distinct objects")
         weakdict = klass()
         o = weakdict.setdefault(key, value1)
-        self.assertTrue(o is value1)
+        self.assertIs(o, value1)
         self.assertIn(key, weakdict)
-        self.assertTrue(weakdict.get(key) is value1)
+        self.assertIs(weakdict.get(key), value1)
-        self.assertTrue(weakdict[key] is value1)
+        self.assertIs(weakdict[key], value1)
 
         o = weakdict.setdefault(key, value2)
-        self.assertTrue(o is value1)
+        self.assertIs(o, value1)
         self.assertIn(key, weakdict)
-        self.assertTrue(weakdict.get(key) is value1)
+        self.assertIs(weakdict.get(key), value1)
-        self.assertTrue(weakdict[key] is value1)
+        self.assertIs(weakdict[key], value1)
 
     def test_weak_valued_dict_setdefault(self):
         self.check_setdefault(weakref.WeakValueDictionary,
@@ -1442,13 +1439,13 @@ def check_update(self, klass, dict):
         for k in weakdict.keys():
             self.assertIn(k, dict, "mysterious new key appeared in weak dict")
             v = dict.get(k)
-            self.assertTrue(v is weakdict[k])
+            self.assertIs(v, weakdict[k])
-            self.assertTrue(v is weakdict.get(k))
+            self.assertIs(v, weakdict.get(k))
         for k in dict.keys():
             self.assertIn(k, weakdict, "original key disappeared in weak dict")
             v = dict[k]
-            self.assertTrue(v is weakdict[k])
+            self.assertIs(v, weakdict[k])
-            self.assertTrue(v is weakdict.get(k))
+            self.assertIs(v, weakdict.get(k))
 
     def test_weak_valued_dict_update(self):
         self.check_update(weakref.WeakValueDictionary,
@@ -1478,7 +1475,7 @@ def test_weak_valued_delitem(self):
         self.assertEqual(len(d), 2)
         del d['something']
         self.assertEqual(len(d), 1)
-        self.assertTrue(list(d.items()) == [('something else', o2)])
+        self.assertEqual(list(d.items()), [('something else', o2)])
 
     def test_weak_keyed_bad_delitem(self):
         d = weakref.WeakKeyDictionary()