Only count obviously non-terminating while-loops as return-ended (#8292)

4 files changed, 61 insertions, 4 deletions

diff --git a/doc/whatsnew/fragments/8280.false_negative b/doc/whatsnew/fragments/8280.false_negative
new file mode 100644
index 000000000..848b71d7c
--- /dev/null
+++ b/doc/whatsnew/fragments/8280.false_negative
@@ -0,0 +1,3 @@
+Fix false negative for inconsistent-returns with while-loops.
+
+Closes #8280
diff --git a/pylint/checkers/refactoring/refactoring_checker.py b/pylint/checkers/refactoring/refactoring_checker.py
index 0caa2fbb5..5aaedf794 100644
--- a/pylint/checkers/refactoring/refactoring_checker.py
+++ b/pylint/checkers/refactoring/refactoring_checker.py
@@ -20,6 +20,7 @@ from astroid.util import Uninferable
 
 from pylint import checkers
 from pylint.checkers import utils
+from pylint.checkers.base.basic_error_checker import _loop_exits_early
 from pylint.checkers.utils import node_frame_class
 from pylint.interfaces import HIGH, INFERENCE, Confidence
 
@@ -1945,10 +1946,12 @@ class RefactoringChecker(checkers.BaseTokenChecker):
                     return True
             except astroid.InferenceError:
                 pass
-        # Avoid the check inside while loop as we don't know
-        # if they will be completed
         if isinstance(node, nodes.While):
-            return True
+            # A while-loop is considered return-ended if it has a
+            # truthy test and no break statements
+            return (node.test.bool_value() and not _loop_exits_early(node)) or any(
+                self._is_node_return_ended(child) for child in node.orelse
+            )
         if isinstance(node, nodes.Raise):
             return self._is_raise_node_return_ended(node)
         if isinstance(node, nodes.If):
diff --git a/tests/functional/i/inconsistent/inconsistent_returns.py b/tests/functional/i/inconsistent/inconsistent_returns.py
index c1183b288..4e9a68377 100644
--- a/tests/functional/i/inconsistent/inconsistent_returns.py
+++ b/tests/functional/i/inconsistent/inconsistent_returns.py
@@ -1,5 +1,5 @@
 #pylint: disable=missing-docstring, no-else-return, no-else-break, invalid-name, unused-variable, superfluous-parens, try-except-raise
-#pylint: disable=disallowed-name
+#pylint: disable=disallowed-name,too-few-public-methods,no-member,useless-else-on-loop
 """Testing inconsistent returns"""
 import math
 import sys
@@ -353,3 +353,52 @@ def bug_pylint_4019_wrong(x):  # [inconsistent-return-statements]
     if x == 1:
         return 42
     assert True
+
+
+# https://github.com/PyCQA/pylint/issues/8280
+class A:
+    def get_the_answer(self):  # [inconsistent-return-statements]
+        while self.is_running:
+            self.read_message()
+            if self.comunication_finished():
+                return "done"
+
+
+def bug_1772_break():  # [inconsistent-return-statements]
+    counter = 1
+    while True:
+        counter += 1
+        if counter == 100:
+            return 7
+        if counter is None:
+            break
+
+
+def while_break_in_for():
+    counter = 1
+    while True:
+        counter += 1
+        if counter == 100:
+            return 7
+        for i in range(10):
+            if i == 5:
+                break
+
+
+def while_break_in_while():
+    counter = 1
+    while True:
+        counter += 1
+        if counter == 100:
+            return 7
+        while True:
+            if counter == 5:
+                break
+
+
+def wait_for_apps_ready(event, main_thread):
+    while main_thread.is_alive():
+        if event.wait(timeout=0.1):
+            return True
+    else:
+        return False
diff --git a/tests/functional/i/inconsistent/inconsistent_returns.txt b/tests/functional/i/inconsistent/inconsistent_returns.txt
index 8e67a83f8..125f3dec7 100644
--- a/tests/functional/i/inconsistent/inconsistent_returns.txt
+++ b/tests/functional/i/inconsistent/inconsistent_returns.txt
@@ -15,3 +15,5 @@ inconsistent-return-statements:267:0:267:12:bug_3468:Either all return statement
 inconsistent-return-statements:277:0:277:20:bug_3468_variant:Either all return statements in a function should return an expression, or none of them should.:UNDEFINED
 inconsistent-return-statements:322:0:322:21:bug_pylint_3873_1:Either all return statements in a function should return an expression, or none of them should.:UNDEFINED
 inconsistent-return-statements:349:0:349:25:bug_pylint_4019_wrong:Either all return statements in a function should return an expression, or none of them should.:UNDEFINED
+inconsistent-return-statements:360:4:360:22:A.get_the_answer:Either all return statements in a function should return an expression, or none of them should.:UNDEFINED
+inconsistent-return-statements:367:0:367:18:bug_1772_break:Either all return statements in a function should return an expression, or none of them should.:UNDEFINED