Merged in vtemian/pylint/redundant-assert (pull request #202)

Added check for redundant assert #ropython-sprints

1 files changed, 24 insertions, 6 deletions

diff --git a/checkers/stdlib.py b/checkers/stdlib.py
index fadb58678..8f1965eaf 100644
--- a/checkers/stdlib.py
+++ b/checkers/stdlib.py
@@ -93,16 +93,26 @@ class StdlibChecker(BaseChecker):
                   'midnight UTC. This behaviour was fixed in Python 3.5. '
                   'See http://bugs.python.org/issue13936 for reference.',
                   {'maxversion': (3, 5)}),
-        }
-
-    @utils.check_messages('bad-open-mode')
+        'W1503': ('Redundant use of assertTrue or assertFalse with constant '
+                  'value %r',
+                  'redundant-unittest-assert',
+                  'The first argument of assertTrue and assertFalse is'
+                  'a condition. If a constant is passed as parameter, that'
+                  'condition will be always true. In this case a warning '
+                  'should be emited.')
+    }
+
+    @utils.check_messages('bad-open-mode', 'redundant-unittest-assert')
     def visit_callfunc(self, node):
         """Visit a CallFunc node."""
         if hasattr(node, 'func'):
             infer = utils.safe_infer(node.func)
-            if infer and infer.root().name == OPEN_MODULE:
-                if getattr(node.func, 'name', None) in ('open', 'file'):
-                    self._check_open_mode(node)
+            if infer:
+                if infer.root().name == OPEN_MODULE:
+                    if getattr(node.func, 'name', None) in ('open', 'file'):
+                        self._check_open_mode(node)
+                if infer.root().name == 'unittest.case':
+                    self._check_redundant_assert(node, infer)
 
     @utils.check_messages('boolean-datetime')
     def visit_unaryop(self, node):
@@ -122,6 +132,14 @@ class StdlibChecker(BaseChecker):
         for value in node.values:
             self._check_datetime(value)
 
+    def _check_redundant_assert(self, node, infer):
+        if (isinstance(infer, astroid.BoundMethod) and
+                isinstance(node.args[0], astroid.Const) and
+                infer.name in ['assertTrue', 'assertFalse']):
+            self.add_message('redundant-unittest-assert',
+                             args=(node.args[0].value, ),
+                             node=node)
+
     def _check_datetime(self, node):
         """ Check that a datetime was infered.
         If so, emit boolean-datetime warning.