Add tests for crash on assignment expressions in if statemenpytts

Author: DanielNoord

ChangeLog

@@ -114,6 +114,10 @@ Release date: TBA
 
   Closes #5222
 
+* ``pylint`` no longer crashes when checking assignment expressions within if-statements
+
+  Closes #5178
+
 * Update ``literal-comparison``` checker to ignore tuple literals
 
   Closes #3031

doc/whatsnew/2.12.rst

@@ -73,6 +73,10 @@ Other Changes
 
 * Fix ``install graphiz`` message which isn't needed for puml output format.
 
+* ``pylint`` no longer crashes when checking assignment expressions within if-statements
+
+  Closes #5178
+
 * Fix ``simplify-boolean-expression`` when condition can be inferred as False.
 
   Closes #5200

tests/functional/a/assign/assignment_expression.py

@@ -94,3 +94,20 @@ def func3():
 # Lambda and IfExp
 def func4():
     l = lambda x: y if (y := x) else None
+
+
+# Crash related to assignment expression in nested if statements
+# See https://github.com/PyCQA/pylint/issues/5178
+def func5(val):
+    variable = None
+
+    if val == 1:
+        variable = "value"
+        if variable := "value":
+            pass
+
+    elif val == 2:
+        variable = "value_two"
+        variable = "value_two"
+
+    return variable