1 files changed, 162 insertions, 0 deletions
diff --git a/tests/functional/u/unbalanced/unbalanced_tuple_unpacking.py b/tests/functional/u/unbalanced/unbalanced_tuple_unpacking.py
new file mode 100644
index 000000000..21e497be8
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+++ b/tests/functional/u/unbalanced/unbalanced_tuple_unpacking.py
@@ -0,0 +1,162 @@
+"""Check possible unbalanced tuple unpacking """
+from __future__ import absolute_import
+from typing import NamedTuple
+from functional.u.unpacking.unpacking import unpack
+
+# pylint: disable=missing-class-docstring, missing-function-docstring, using-constant-test, import-outside-toplevel
+
+
+def do_stuff():
+    """This is not right."""
+    first, second = 1, 2, 3  # [unbalanced-tuple-unpacking]
+    return first + second
+
+
+def do_stuff1():
+    """This is not right."""
+    first, second = [1, 2, 3]  # [unbalanced-tuple-unpacking]
+    return first + second
+
+
+def do_stuff2():
+    """This is not right."""
+    (first, second) = 1, 2, 3  # [unbalanced-tuple-unpacking]
+    return first + second
+
+
+def do_stuff3():
+    """This is not right."""
+    first, second = range(100)
+    return first + second
+
+
+def do_stuff4():
+    """This is right"""
+    first, second = 1, 2
+    return first + second
+
+
+def do_stuff5():
+    """This is also right"""
+    first, second = (1, 2)
+    return first + second
+
+
+def do_stuff6():
+    """This is right"""
+    (first, second) = (1, 2)
+    return first + second
+
+
+def temp():
+    """This is not weird"""
+    if True:
+        return [1, 2]
+    return [2, 3, 4]
+
+
+def do_stuff7():
+    """This is not right, but we're not sure"""
+    first, second = temp()
+    return first + second
+
+
+def temp2():
+    """This is weird, but correct"""
+    if True:
+        return (1, 2)
+
+    if True:
+        return (2, 3)
+    return (4, 5)
+
+
+def do_stuff8():
+    """This is correct"""
+    first, second = temp2()
+    return first + second
+
+
+def do_stuff9():
+    """This is not correct"""
+    first, second = unpack()  # [unbalanced-tuple-unpacking]
+    return first + second
+
+
+class UnbalancedUnpacking:
+    """Test unbalanced tuple unpacking in instance attributes."""
+
+    # pylint: disable=attribute-defined-outside-init, invalid-name, too-few-public-methods
+    def test(self):
+        """unpacking in instance attributes"""
+        # we're not sure if temp() returns two or three values
+        # so we shouldn't emit an error
+        self.a, self.b = temp()
+        self.a, self.b = temp2()
+        self.a, self.b = unpack()  # [unbalanced-tuple-unpacking]
+
+
+def issue329(*args):
+    """Don't emit unbalanced tuple unpacking if the
+    rhs of the assignment is a variable-length argument,
+    because we don't know the actual length of the tuple.
+    """
+    first, second, third = args
+    return first, second, third
+
+
+def test_decimal():
+    """Test a false positive with decimal.Decimal.as_tuple
+
+    See astroid https://bitbucket.org/logilab/astroid/issues/92/
+    """
+    from decimal import Decimal
+
+    dec = Decimal(2)
+    first, second, third = dec.as_tuple()
+    return first, second, third
+
+
+def test_issue_559():
+    """Test that we don't have a false positive wrt to issue #559."""
+    from ctypes import c_int
+
+    root_x, root_y, win_x, win_y = [c_int()] * 4
+    return root_x, root_y, win_x, win_y
+
+
+class MyClass(NamedTuple):
+    first: float
+    second: float
+    third: float = 1.0
+
+    def my_sum(self):
+        """Unpack 3 variables"""
+        first, second, third = self
+        return first + second + third
+
+    def sum_unpack_3_into_4(self):
+        """Attempt to unpack 3 variables into 4"""
+        first, second, third, fourth = self  # [unbalanced-tuple-unpacking]
+        return first + second + third + fourth
+
+    def sum_unpack_3_into_2(self):
+        """Attempt to unpack 3 variables into 2"""
+        first, second = self  # [unbalanced-tuple-unpacking]
+        return first + second
+
+
+def my_function(mystring):
+    """The number of items on the right-hand-side of the assignment to this function is not known"""
+    mylist = []
+    for item in mystring:
+        mylist.append(item)
+    return mylist
+
+
+a, b = my_function("12")  # [unbalanced-tuple-unpacking]
+c = my_function("12")
+d, *_ = my_function("12")
+
+# https://github.com/pylint-dev/pylint/issues/5998
+x, y, z = (1, 2)  # [unbalanced-tuple-unpacking]