python: tests: use more targeted assert*() functions/checks

- use assertIsInstance, assertNotEqual, and assertIsNotNone as more
  specific checks (will produce better logging)
- use assertRaises when expecting exceptions being thrown
- when testing internal_test_rhashtable, instead of checking type and
  elements of the return values just check the return value as a whole
  (easier and already getting all the work needed by unittest)

python/t/080-version.py

@@ -34,13 +34,13 @@ class Test080Version (unittest.TestCase):
         self.assertEqual (self.version['major'], 1)
 
     def test_minor (self):
-        self.assertTrue (isinstance (self.version['minor'], cl))
+        self.assertIsInstance (self.version['minor'], cl)
 
     def test_release (self):
-        self.assertTrue (isinstance (self.version['release'], cl))
+        self.assertIsInstance (self.version['release'], cl)
 
     def test_extra (self):
-        self.assertTrue (isinstance (self.version['extra'], str))
+        self.assertIsInstance (self.version['extra'], str)
 
 if __name__ == '__main__':
     unittest.main ()

python/t/420-log-messages.py

@@ -51,7 +51,7 @@ class Test420LogMessages (unittest.TestCase):
 
         g.close ()
 
-        self.assertFalse (log_invoked == 0)
+        self.assertNotEqual (log_invoked, 0)
 
 if __name__ == '__main__':
     unittest.main ()

python/t/800-explicit-close.py

@@ -37,11 +37,7 @@ class Test800ExplicitClose (unittest.TestCase):
         # Expect an exception if we call a method on a closed handle.
         g = guestfs.GuestFS (python_return_dict=True)
         g.close ()
-        try:
-            g.set_memsize (512)
-            raise Exception("expected an exception from previous statement")
-        except guestfs.ClosedHandle:
-            pass
+        self.assertRaises (guestfs.ClosedHandle, g.set_memsize, 512)
         del g
 
         # Verify that the handle is really being closed by g.close, by

python/t/810-rhbz811650.py

@@ -31,10 +31,7 @@ class Test810RHBZ811650 (unittest.TestCase):
         # Because error() wasn't being called, guestfs_last_error
         # would return NULL, causing a segfault in the Python bindings
         # (RHBZ#811650).
-        try:
-            g.launch ()
-        except:
-            pass
+        self.assertRaises (RuntimeError, g.launch)
 
     def tearDown (self):
         os.unlink ("rhbz811650.img")

python/t/820-rhbz912499.py

@@ -89,7 +89,7 @@ class Test820RHBZ912499 (unittest.TestCase):
     def test_rhbz912499 (self):
         dom = conn.createXML (self.xml,
                               libvirt.VIR_DOMAIN_START_AUTODESTROY)
-        self.assertFalse (dom == None)
+        self.assertIsNotNone (dom)
 
         print ("temporary domain %s is running" % self.domname)
 

python/t/900-python-dict.py

@@ -27,7 +27,6 @@ class Test900PythonDict (unittest.TestCase):
         g = guestfs.GuestFS (python_return_dict=False)
 
         r = g.internal_test_rhashtable ("5")
-        self.assertTrue (isinstance (r, list))
         self.assertEqual (r, [ ("0","0"), ("1","1"), ("2","2"),
                                ("3","3"), ("4","4") ])
 
@@ -35,13 +34,7 @@ class Test900PythonDict (unittest.TestCase):
         g = guestfs.GuestFS (python_return_dict=True)
 
         r = g.internal_test_rhashtable ("5")
-        self.assertTrue (isinstance (r, dict))
-        self.assertEqual (sorted (r.keys()), ["0","1","2","3","4"])
-        self.assertEqual (r["0"], "0")
-        self.assertEqual (r["1"], "1")
-        self.assertEqual (r["2"], "2")
-        self.assertEqual (r["3"], "3")
-        self.assertEqual (r["4"], "4")
+        self.assertEqual (r, {"0": "0", "1": "1", "2": "2", "3": "3", "4": "4"})
 
 if __name__ == '__main__':
     unittest.main ()