check if the type of a variable is redefined (at a function, class or module scope)

related to issue #674

5 files changed, 59 insertions, 3 deletions

diff --git a/pylint/test/functional/bad_continuation.py b/pylint/test/functional/bad_continuation.py
index 34292ab..c0918a6 100644
--- a/pylint/test/functional/bad_continuation.py
+++ b/pylint/test/functional/bad_continuation.py
@@ -1,5 +1,5 @@
 """Regression test case for bad-continuation."""
-# pylint: disable=print-statement,using-constant-test
+# pylint: disable=print-statement,using-constant-test, redefined-variable-type
 # Various alignment for brackets
 from __future__ import print_function
 
diff --git a/pylint/test/functional/member_checks.py b/pylint/test/functional/member_checks.py
index 50a0d97..9692e05 100644
--- a/pylint/test/functional/member_checks.py
+++ b/pylint/test/functional/member_checks.py
@@ -1,5 +1,5 @@
 # pylint: disable=print-statement,missing-docstring,no-self-use,too-few-public-methods,bare-except,broad-except
-# pylint: disable=using-constant-test,expression-not-assigned
+# pylint: disable=using-constant-test,expression-not-assigned, redefined-variable-type
 from __future__ import print_function
 
 class Provider(object):
diff --git a/pylint/test/functional/redefined_variable_type.py b/pylint/test/functional/redefined_variable_type.py
new file mode 100644
index 0000000..9851702
--- /dev/null
+++ b/pylint/test/functional/redefined_variable_type.py
@@ -0,0 +1,50 @@
+"""Checks variable types aren't redefined within a method or a function"""
+
+# pylint: disable=too-few-public-methods, missing-docstring, unused-variable
+
+_OK = True
+
+def my_func():
+    var = 'foo'
+    var = 'bar'
+    var = var.split()  # [redefined-variable-type]
+
+class MyClass(object):
+    def __init__(self):
+        self.var = True
+        self.var1 = 2
+        self.var2 = 1.
+        self.var1 = 2.  # [redefined-variable-type]
+        self.a_str = "hello"
+        a_str = False
+        (a_str, b_str) = (1, 2)
+        a_str = 2.0 if self.var else 1.0
+
+    def _getter(self):
+        return self.a_str
+    def _setter(self, val):
+        self.a_str = val
+    var2 = property(_getter, _setter)
+
+    def some_method(self):
+        self.var = 1
+        test = 'foo'
+        myint = 2
+        myint = False  # [redefined-variable-type]
+
+_OK = "This is OK"  # [redefined-variable-type]
+
+SOME_FLOAT = 1.
+
+def dummy_function():
+    return 2
+
+def other_function():
+    instance = MyClass()
+    instance = True  # [redefined-variable-type]
+
+SOME_FLOAT = dummy_function()  # [redefined-variable-type]
+
+A_GLOB = None
+A_GLOB = [1, 2, 3]
+
diff --git a/pylint/test/functional/redefined_variable_type.txt b/pylint/test/functional/redefined_variable_type.txt
new file mode 100644
index 0000000..329d4d6
--- /dev/null
+++ b/pylint/test/functional/redefined_variable_type.txt
@@ -0,0 +1,6 @@
+redefined-variable-type:10:my_func:Redefinition of var type from str to list
+redefined-variable-type:17:MyClass.__init__:Redefinition of self.var1 type from int to float
+redefined-variable-type:33:MyClass.some_method:Redefinition of myint type from int to bool
+redefined-variable-type:35::Redefinition of _OK type from bool to str
+redefined-variable-type:44:other_function:Redefinition of instance type from functional.redefined_variable_type.MyClass to bool
+redefined-variable-type:46::Redefinition of SOME_FLOAT type from float to int
diff --git a/pylint/test/functional/undefined_variable.py b/pylint/test/functional/undefined_variable.py
index 44a0652..538cff1 100644
--- a/pylint/test/functional/undefined_variable.py
+++ b/pylint/test/functional/undefined_variable.py
@@ -1,4 +1,4 @@
-# pylint: disable=missing-docstring, multiple-statements
+# pylint: disable=missing-docstring, multiple-statements, redefined-variable-type
 # pylint: disable=too-few-public-methods, no-init, no-self-use, old-style-class,bare-except,broad-except
 from __future__ import print_function
 DEFINED = 1