bpo-38530: Require 50% similarity in NameError and AttributeError suggestions (GH-25584)

1 files changed, 112 insertions, 0 deletions

diff --git a/Lib/test/test_exceptions.py b/Lib/test/test_exceptions.py
index b3c00b0..590935c 100644
--- a/Lib/test/test_exceptions.py
+++ b/Lib/test/test_exceptions.py
@@ -1507,6 +1507,61 @@ class NameErrorTests(unittest.TestCase):
 
         self.assertNotIn("somethingverywronghehe", err.getvalue())
 
+    def test_name_error_bad_suggestions_do_not_trigger_for_small_names(self):
+        vvv = mom = w = id = pytho = None
+
+        with self.subTest(name="b"):
+            try:
+                b
+            except NameError as exc:
+                with support.captured_stderr() as err:
+                    sys.__excepthook__(*sys.exc_info())
+            self.assertNotIn("you mean", err.getvalue())
+            self.assertNotIn("vvv", err.getvalue())
+            self.assertNotIn("mom", err.getvalue())
+            self.assertNotIn("'id'", err.getvalue())
+            self.assertNotIn("'w'", err.getvalue())
+            self.assertNotIn("'pytho'", err.getvalue())
+
+        with self.subTest(name="v"):
+            try:
+                v
+            except NameError as exc:
+                with support.captured_stderr() as err:
+                    sys.__excepthook__(*sys.exc_info())
+            self.assertNotIn("you mean", err.getvalue())
+            self.assertNotIn("vvv", err.getvalue())
+            self.assertNotIn("mom", err.getvalue())
+            self.assertNotIn("'id'", err.getvalue())
+            self.assertNotIn("'w'", err.getvalue())
+            self.assertNotIn("'pytho'", err.getvalue())
+
+        with self.subTest(name="m"):
+            try:
+                m
+            except NameError as exc:
+                with support.captured_stderr() as err:
+                    sys.__excepthook__(*sys.exc_info())
+            self.assertNotIn("you mean", err.getvalue())
+            self.assertNotIn("vvv", err.getvalue())
+            self.assertNotIn("mom", err.getvalue())
+            self.assertNotIn("'id'", err.getvalue())
+            self.assertNotIn("'w'", err.getvalue())
+            self.assertNotIn("'pytho'", err.getvalue())
+
+        with self.subTest(name="py"):
+            try:
+                py
+            except NameError as exc:
+                with support.captured_stderr() as err:
+                    sys.__excepthook__(*sys.exc_info())
+            self.assertNotIn("you mean", err.getvalue())
+            self.assertNotIn("vvv", err.getvalue())
+            self.assertNotIn("mom", err.getvalue())
+            self.assertNotIn("'id'", err.getvalue())
+            self.assertNotIn("'w'", err.getvalue())
+            self.assertNotIn("'pytho'", err.getvalue())
+
     def test_name_error_suggestions_do_not_trigger_for_too_many_locals(self):
         def f():
             # Mutating locals() is unreliable, so we need to do it by hand
@@ -1661,6 +1716,63 @@ class AttributeErrorTests(unittest.TestCase):
 
         self.assertNotIn("blech", err.getvalue())
 
+    def test_getattr_error_bad_suggestions_do_not_trigger_for_small_names(self):
+        class MyClass:
+            vvv = mom = w = id = pytho = None
+
+        with self.subTest(name="b"):
+            try:
+                MyClass.b
+            except AttributeError as exc:
+                with support.captured_stderr() as err:
+                    sys.__excepthook__(*sys.exc_info())
+            self.assertNotIn("you mean", err.getvalue())
+            self.assertNotIn("vvv", err.getvalue())
+            self.assertNotIn("mom", err.getvalue())
+            self.assertNotIn("'id'", err.getvalue())
+            self.assertNotIn("'w'", err.getvalue())
+            self.assertNotIn("'pytho'", err.getvalue())
+
+        with self.subTest(name="v"):
+            try:
+                MyClass.v
+            except AttributeError as exc:
+                with support.captured_stderr() as err:
+                    sys.__excepthook__(*sys.exc_info())
+            self.assertNotIn("you mean", err.getvalue())
+            self.assertNotIn("vvv", err.getvalue())
+            self.assertNotIn("mom", err.getvalue())
+            self.assertNotIn("'id'", err.getvalue())
+            self.assertNotIn("'w'", err.getvalue())
+            self.assertNotIn("'pytho'", err.getvalue())
+
+        with self.subTest(name="m"):
+            try:
+                MyClass.m
+            except AttributeError as exc:
+                with support.captured_stderr() as err:
+                    sys.__excepthook__(*sys.exc_info())
+            self.assertNotIn("you mean", err.getvalue())
+            self.assertNotIn("vvv", err.getvalue())
+            self.assertNotIn("mom", err.getvalue())
+            self.assertNotIn("'id'", err.getvalue())
+            self.assertNotIn("'w'", err.getvalue())
+            self.assertNotIn("'pytho'", err.getvalue())
+
+        with self.subTest(name="py"):
+            try:
+                MyClass.py
+            except AttributeError as exc:
+                with support.captured_stderr() as err:
+                    sys.__excepthook__(*sys.exc_info())
+            self.assertNotIn("you mean", err.getvalue())
+            self.assertNotIn("vvv", err.getvalue())
+            self.assertNotIn("mom", err.getvalue())
+            self.assertNotIn("'id'", err.getvalue())
+            self.assertNotIn("'w'", err.getvalue())
+            self.assertNotIn("'pytho'", err.getvalue())
+
+
     def test_getattr_suggestions_do_not_trigger_for_big_dicts(self):
         class A:
             blech = None