From b32f9ac7893e31beeaf37349117c6afb4f19ab15 Mon Sep 17 00:00:00 2001
From: Ryan Downing <26515643+r-downing@users.noreply.github.com>
Date: Wed, 29 Nov 2023 23:59:33 -0500
Subject: [PATCH 1/3] include tuples in b018 useless-statement check

---
 bugbear.py              | 1 +
 tests/b018_classes.py   | 3 +++
 tests/b018_functions.py | 3 +++
 tests/b018_modules.py   | 3 +++
 tests/test_bugbear.py   | 6 +++++-
 5 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/bugbear.py b/bugbear.py
index 54a13a8..81e619d 100644
--- a/bugbear.py
+++ b/bugbear.py
@@ -1173,6 +1173,7 @@ def check_for_b018(self, node):
                     ast.List,
                     ast.Set,
                     ast.Dict,
+                    ast.Tuple,
                 ),
             ) or (
                 isinstance(subnode.value, ast.Constant)
diff --git a/tests/b018_classes.py b/tests/b018_classes.py
index 4dc9ca2..742e1bb 100644
--- a/tests/b018_classes.py
+++ b/tests/b018_classes.py
@@ -30,3 +30,6 @@ class Foo3:
     a = 2
     "str"
     1
+    (1,)
+    (2, 3)
+    t = (4, 5)
diff --git a/tests/b018_functions.py b/tests/b018_functions.py
index a4c2b49..582e7c5 100644
--- a/tests/b018_functions.py
+++ b/tests/b018_functions.py
@@ -29,3 +29,6 @@ def foo3():
     a = 2
     "str"
     3
+    (1,)
+    (2, 3)
+    t = (4, 5)
diff --git a/tests/b018_modules.py b/tests/b018_modules.py
index 70d6e59..69ce85e 100644
--- a/tests/b018_modules.py
+++ b/tests/b018_modules.py
@@ -16,3 +16,6 @@
 [1, 2]  # list
 {1, 2}  # set
 {"foo": "bar"}  # dict
+(1,)
+(2, 3)
+t = (4, 5)
diff --git a/tests/test_bugbear.py b/tests/test_bugbear.py
index 3ea3e42..aa20b69 100644
--- a/tests/test_bugbear.py
+++ b/tests/test_bugbear.py
@@ -270,6 +270,8 @@ def test_b018_functions(self):
         expected = [B018(line, 4) for line in range(15, 25)]
         expected.append(B018(28, 4))
         expected.append(B018(31, 4))
+        expected.append(B018(32, 4))
+        expected.append(B018(33, 4))
         self.assertEqual(errors, self.errors(*expected))
 
     def test_b018_classes(self):
@@ -280,6 +282,8 @@ def test_b018_classes(self):
         expected = [B018(line, 4) for line in range(16, 26)]
         expected.append(B018(29, 4))
         expected.append(B018(32, 4))
+        expected.append(B018(33, 4))
+        expected.append(B018(34, 4))
         self.assertEqual(errors, self.errors(*expected))
 
     def test_b018_modules(self):
@@ -287,7 +291,7 @@ def test_b018_modules(self):
         bbc = BugBearChecker(filename=str(filename))
         errors = list(bbc.run())
 
-        expected = [B018(line, 0) for line in range(9, 19)]
+        expected = [B018(line, 0) for line in range(9, 21)]
         self.assertEqual(errors, self.errors(*expected))
 
     def test_b019(self):

From 1a14418842bf329c8b3083d3361eaa303edd3cba Mon Sep 17 00:00:00 2001
From: Ryan Downing <26515643+r-downing@users.noreply.github.com>
Date: Thu, 30 Nov 2023 17:09:07 -0500
Subject: [PATCH 2/3] annotate the bad and good test lines

---
 tests/b018_classes.py   | 6 +++---
 tests/b018_functions.py | 6 +++---
 tests/b018_modules.py   | 6 +++---
 3 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/tests/b018_classes.py b/tests/b018_classes.py
index 742e1bb..8150a33 100644
--- a/tests/b018_classes.py
+++ b/tests/b018_classes.py
@@ -30,6 +30,6 @@ class Foo3:
     a = 2
     "str"
     1
-    (1,)
-    (2, 3)
-    t = (4, 5)
+    (1,)  # bad
+    (2, 3)  # bad
+    t = (4, 5)  # good
diff --git a/tests/b018_functions.py b/tests/b018_functions.py
index 582e7c5..c3e5440 100644
--- a/tests/b018_functions.py
+++ b/tests/b018_functions.py
@@ -29,6 +29,6 @@ def foo3():
     a = 2
     "str"
     3
-    (1,)
-    (2, 3)
-    t = (4, 5)
+    (1,)  # bad
+    (2, 3)  # bad
+    t = (4, 5)  # good
diff --git a/tests/b018_modules.py b/tests/b018_modules.py
index 69ce85e..eb94008 100644
--- a/tests/b018_modules.py
+++ b/tests/b018_modules.py
@@ -16,6 +16,6 @@
 [1, 2]  # list
 {1, 2}  # set
 {"foo": "bar"}  # dict
-(1,)
-(2, 3)
-t = (4, 5)
+(1,)  # bad
+(2, 3)  # bad
+t = (4, 5)  # good

From 4cd8b6ae9ac9fa22be8288e7e97e50d9e759101c Mon Sep 17 00:00:00 2001
From: Ryan Downing <26515643+r-downing@users.noreply.github.com>
Date: Thu, 30 Nov 2023 23:53:04 -0500
Subject: [PATCH 3/3] update readme w/ notes about comma

---
 README.rst | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/README.rst b/README.rst
index d7a4c0f..be5c7df 100644
--- a/README.rst
+++ b/README.rst
@@ -137,6 +137,9 @@ using ``pytest.raises``), or use the context manager form with a target
 (e.g. ``with self.assertRaises(Exception) as ex:``).
 
 **B018**: Found useless expression. Either assign it to a variable or remove it.
+Note that dangling commas will cause things to be interpreted as useless tuples.
+For example, in the statement ``print(".."),`` is the same as ``(print(".."),)``
+which is an unassigned tuple. Simply remove the comma to clear the error.
 
 **B019**: Use of ``functools.lru_cache`` or ``functools.cache`` on methods
 can lead to memory leaks. The cache may retain instance references, preventing