Add new checker `bad-chained-comparison` (#7990)

Co-authored-by: Pierre Sassoulas <pierre.sassoulas@gmail.com>

4 files changed, 64 insertions, 2 deletions

diff --git a/tests/functional/b/bad_chained_comparison.py b/tests/functional/b/bad_chained_comparison.py
new file mode 100644
index 000000000..c1bdab980
--- /dev/null
+++ b/tests/functional/b/bad_chained_comparison.py
@@ -0,0 +1,51 @@
+# pylint: disable=invalid-name
+"""Checks for chained comparisons with comparisons belonging to different groups"""
+
+primes = set(2, 3, 5, 7, 11)
+
+def valid(x, y, z):
+    """valid usage of chained comparisons"""
+    if x < y <= z:
+        pass
+    elif x > y >= z:
+        pass
+    elif x == y != z:
+        pass
+    elif x is y is not z:
+        pass
+    elif x in y not in z:
+        pass
+
+def id_comparison_invalid(*, left=None, right=None):
+    """identity mixed with comparison"""
+    if left is None != right is None:  # [bad-chained-comparison]
+        raise ValueError('Either both left= and right= need to be provided or none should.')
+    if left is not None == right is not None:  # [bad-chained-comparison]
+        pass
+
+def member_comparison_invalid(x:int, y:int, z:int):
+    """membership mixed with comparison"""
+    if x in primes == y in primes:  # [bad-chained-comparison]
+        pass
+    elif x in primes == z not in primes:  # [bad-chained-comparison]
+        pass
+    elif x not in primes == y in primes != z not in primes:  # [bad-chained-comparison]
+        pass
+    elif x not in primes <= y not in primes > z in primes:  # [bad-chained-comparison]
+        pass
+
+def id_member_invalid(x:int, y:int, z:int):
+    """identity mixed with membership"""
+    if x in primes is y in primes:  # [bad-chained-comparison]
+        pass
+    elif x in primes is z not in primes:  # [bad-chained-comparison]
+        pass
+    elif x not in primes is y in primes is not z not in primes:  # [bad-chained-comparison]
+        pass
+
+def complex_invalid(x:int, y:int, z:int):
+    """invalid complex chained comparisons"""
+    if x in primes == y not in primes is not z in primes:  # [bad-chained-comparison]
+        pass
+    elif x < y <= z != x not in primes is y in primes:  # [bad-chained-comparison]
+        pass
diff --git a/tests/functional/b/bad_chained_comparison.txt b/tests/functional/b/bad_chained_comparison.txt
new file mode 100644
index 000000000..276a1debc
--- /dev/null
+++ b/tests/functional/b/bad_chained_comparison.txt
@@ -0,0 +1,11 @@
+bad-chained-comparison:21:7:21:36:id_comparison_invalid:Suspicious 3-part chained comparison using semantically incompatible operators ('!=' and 'is'):HIGH
+bad-chained-comparison:23:7:23:44:id_comparison_invalid:Suspicious 3-part chained comparison using semantically incompatible operators ('==' and 'is not'):HIGH
+bad-chained-comparison:28:7:28:33:member_comparison_invalid:Suspicious 3-part chained comparison using semantically incompatible operators ('==' and 'in'):HIGH
+bad-chained-comparison:30:9:30:39:member_comparison_invalid:Suspicious 3-part chained comparison using semantically incompatible operators ('==', 'in' and 'not in'):HIGH
+bad-chained-comparison:32:9:32:58:member_comparison_invalid:Suspicious 5-part chained comparison using semantically incompatible operators ('!=', '==', 'in' and 'not in'):HIGH
+bad-chained-comparison:34:9:34:57:member_comparison_invalid:Suspicious 5-part chained comparison using semantically incompatible operators ('<=', '>', 'in' and 'not in'):HIGH
+bad-chained-comparison:39:7:39:33:id_member_invalid:Suspicious 3-part chained comparison using semantically incompatible operators ('in' and 'is'):HIGH
+bad-chained-comparison:41:9:41:39:id_member_invalid:Suspicious 3-part chained comparison using semantically incompatible operators ('in', 'is' and 'not in'):HIGH
+bad-chained-comparison:43:9:43:62:id_member_invalid:Suspicious 5-part chained comparison using semantically incompatible operators ('in', 'is', 'is not' and 'not in'):HIGH
+bad-chained-comparison:48:7:48:56:complex_invalid:Suspicious 5-part chained comparison using semantically incompatible operators ('==', 'in', 'is not' and 'not in'):HIGH
+bad-chained-comparison:50:9:50:53:complex_invalid:Suspicious 6-part chained comparison using semantically incompatible operators ('!=', '<', '<=', 'in', 'is' and 'not in'):HIGH
diff --git a/tests/functional/c/consider/consider_iterating_dictionary.py b/tests/functional/c/consider/consider_iterating_dictionary.py
index 8c75b4e3e..91402bf77 100644
--- a/tests/functional/c/consider/consider_iterating_dictionary.py
+++ b/tests/functional/c/consider/consider_iterating_dictionary.py
@@ -1,4 +1,4 @@
-# pylint: disable=missing-docstring, expression-not-assigned, too-few-public-methods
+# pylint: disable=missing-docstring, expression-not-assigned, too-few-public-methods, bad-chained-comparison
 # pylint: disable=no-member, import-error, line-too-long
 # pylint: disable=unnecessary-comprehension, use-dict-literal, use-implicit-booleaness-not-comparison
 
diff --git a/tests/functional/ext/set_membership/use_set_membership.py b/tests/functional/ext/set_membership/use_set_membership.py
index 7872d7f98..df5cd961b 100644
--- a/tests/functional/ext/set_membership/use_set_membership.py
+++ b/tests/functional/ext/set_membership/use_set_membership.py
@@ -1,4 +1,4 @@
-# pylint: disable=invalid-name,missing-docstring,pointless-statement,unnecessary-comprehension,undefined-variable
+# pylint: disable=invalid-name,missing-docstring,pointless-statement,unnecessary-comprehension,undefined-variable,bad-chained-comparison
 
 x = 1
 var = frozenset({1, 2, 3})