1 files changed, 76 insertions, 0 deletions
diff --git a/pylint/test/functional/unidiomatic_typecheck.py b/pylint/test/functional/unidiomatic_typecheck.py
new file mode 100644
index 0000000..008456b
--- /dev/null
+++ b/pylint/test/functional/unidiomatic_typecheck.py
@@ -0,0 +1,76 @@
+"""Warnings for using type(x) == Y or type(x) is Y instead of isinstance(x, Y)."""
+# pylint: disable=missing-docstring,expression-not-assigned,redefined-builtin,invalid-name
+
+def simple_positives():
+    type(42) is int # [unidiomatic-typecheck]
+    type(42) is not int # [unidiomatic-typecheck]
+    type(42) == int # [unidiomatic-typecheck]
+    type(42) != int # [unidiomatic-typecheck]
+    type(42) in [int] # [unidiomatic-typecheck]
+    type(42) not in [int] # [unidiomatic-typecheck]
+
+def simple_inference_positives():
+    alias = type
+    alias(42) is int # [unidiomatic-typecheck]
+    alias(42) is not int # [unidiomatic-typecheck]
+    alias(42) == int # [unidiomatic-typecheck]
+    alias(42) != int # [unidiomatic-typecheck]
+    alias(42) in [int] # [unidiomatic-typecheck]
+    alias(42) not in [int] # [unidiomatic-typecheck]
+
+def type_creation_negatives():
+    type('Q', (object,), dict(a=1)) is int
+    type('Q', (object,), dict(a=1)) is not int
+    type('Q', (object,), dict(a=1)) == int
+    type('Q', (object,), dict(a=1)) != int
+    type('Q', (object,), dict(a=1)) in [int]
+    type('Q', (object,), dict(a=1)) not in [int]
+
+def invalid_type_call_negatives(**kwargs):
+    type(bad=7) is int
+    type(bad=7) is not int
+    type(bad=7) == int
+    type(bad=7) != int
+    type(bad=7) in [int]
+    type(bad=7) not in [int]
+    type('bad', 7) is int
+    type('bad', 7) is not int
+    type('bad', 7) == int
+    type('bad', 7) != int
+    type('bad', 7) in [int]
+    type('bad', 7) not in [int]
+    type(**kwargs) is int
+    type(**kwargs) is not int
+    type(**kwargs) == int
+    type(**kwargs) != int
+    type(**kwargs) in [int]
+    type(**kwargs) not in [int]
+
+def local_var_shadowing_inference_negatives():
+    type = lambda dummy: 7
+    type(42) is int
+    type(42) is not int
+    type(42) == int
+    type(42) != int
+    type(42) in [int]
+    type(42) not in [int]
+
+def parameter_shadowing_inference_negatives(type):
+    type(42) is int
+    type(42) is not int
+    type(42) == int
+    type(42) != int
+    type(42) in [int]
+    type(42) not in [int]
+
+def deliberate_subclass_check_negatives(b):
+    type(42) is type(b)
+    type(42) is not type(b)
+
+def type_of_literals_positives(a):
+    type(a) is type([]) # [unidiomatic-typecheck]
+    type(a) is not type([]) # [unidiomatic-typecheck]
+    type(a) is type({}) # [unidiomatic-typecheck]
+    type(a) is not type({}) # [unidiomatic-typecheck]
+    type(a) is type("") # [unidiomatic-typecheck]
+    type(a) is not type("") # [unidiomatic-typecheck]