Use asottile/add-trailing-comma
diff --git a/tests/check_docstring_first_test.py b/tests/check_docstring_first_test.py
index f14880b..aa9898d 100644
--- a/tests/check_docstring_first_test.py
+++ b/tests/check_docstring_first_test.py
@@ -19,7 +19,7 @@
         '"foo"\n',
         1,
         '{filename}:2 Module docstring appears after code '
-        '(code seen on line 1).\n'
+        '(code seen on line 1).\n',
     ),
     # Test double docstring
     (
@@ -28,7 +28,7 @@
         '"fake docstring"\n',
         1,
         '{filename}:3 Multiple module docstrings '
-        '(first docstring on line 1).\n'
+        '(first docstring on line 1).\n',
     ),
     # Test multiple lines of code above
     (
diff --git a/tests/check_merge_conflict_test.py b/tests/check_merge_conflict_test.py
index 5a2e82a..a999aca 100644
--- a/tests/check_merge_conflict_test.py
+++ b/tests/check_merge_conflict_test.py
@@ -45,7 +45,7 @@
             'child\n'
             '=======\n'
             'parent\n'
-            '>>>>>>>'
+            '>>>>>>>',
         ) or f1.startswith(
             '<<<<<<< HEAD\n'
             'child\n'
@@ -53,7 +53,7 @@
             '||||||| merged common ancestors\n'
             '=======\n'
             'parent\n'
-            '>>>>>>>'
+            '>>>>>>>',
         ) or f1.startswith(
             # .gitconfig with [pull] rebase = preserve causes a rebase which
             # flips parent / child
@@ -61,7 +61,7 @@
             'parent\n'
             '=======\n'
             'child\n'
-            '>>>>>>>'
+            '>>>>>>>',
         )
         assert os.path.exists(os.path.join('.git', 'MERGE_MSG'))
         yield
diff --git a/tests/debug_statement_hook_test.py b/tests/debug_statement_hook_test.py
index c318346..7891eac 100644
--- a/tests/debug_statement_hook_test.py
+++ b/tests/debug_statement_hook_test.py
@@ -46,7 +46,7 @@
     visitor = ImportStatementParser()
     visitor.visit(ast_with_debug_import_form_1)
     assert visitor.debug_import_statements == [
-        DebugStatement('ipdb', 3, 0)
+        DebugStatement('ipdb', 3, 0),
     ]
 
 
@@ -54,7 +54,7 @@
     visitor = ImportStatementParser()
     visitor.visit(ast_with_debug_import_form_2)
     assert visitor.debug_import_statements == [
-        DebugStatement('pudb', 3, 0)
+        DebugStatement('pudb', 3, 0),
     ]
 
 
diff --git a/tests/detect_aws_credentials_test.py b/tests/detect_aws_credentials_test.py
index 943a3f8..beb382f 100644
--- a/tests/detect_aws_credentials_test.py
+++ b/tests/detect_aws_credentials_test.py
@@ -21,14 +21,14 @@
         (
             {
                 'AWS_DUMMY_KEY': '/foo', 'AWS_CONFIG_FILE': '/bar',
-                'AWS_CREDENTIAL_FILE': '/baz'
+                'AWS_CREDENTIAL_FILE': '/baz',
             },
             {'/bar', '/baz'}
         ),
         (
             {
                 'AWS_CONFIG_FILE': '/foo', 'AWS_CREDENTIAL_FILE': '/bar',
-                'AWS_SHARED_CREDENTIALS_FILE': '/baz'
+                'AWS_SHARED_CREDENTIALS_FILE': '/baz',
             },
             {'/foo', '/bar', '/baz'}
         ),
@@ -51,7 +51,7 @@
         ({'AWS_DUMMY_KEY': 'foo', 'AWS_SECRET_ACCESS_KEY': 'bar'}, {'bar'}),
         (
             {'AWS_SECRET_ACCESS_KEY': 'foo', 'AWS_SECURITY_TOKEN': 'bar'},
-            {'foo', 'bar'}
+            {'foo', 'bar'},
         ),
     ),
 )
@@ -66,7 +66,7 @@
     (
         (
             'aws_config_with_secret.ini',
-            {'z2rpgs5uit782eapz5l1z0y2lurtsyyk6hcfozlb'}
+            {'z2rpgs5uit782eapz5l1z0y2lurtsyyk6hcfozlb'},
         ),
         ('aws_config_with_session_token.ini', {'foo'}),
         ('aws_config_with_secret_and_session_token.ini',
@@ -77,8 +77,8 @@
                 '7xebzorgm5143ouge9gvepxb2z70bsb2rtrh099e',
                 'z2rpgs5uit782eapz5l1z0y2lurtsyyk6hcfozlb',
                 'ixswosj8gz3wuik405jl9k3vdajsnxfhnpui38ez',
-                'foo'
-            }
+                'foo',
+            },
         ),
         ('aws_config_without_secrets.ini', set()),
         ('nonsense.txt', set()),
@@ -121,7 +121,7 @@
     mock_secrets_file.return_value = set()
     ret = main((
         get_resource_path('aws_config_without_secrets.ini'),
-        "--credentials-file=testing/resources/credentailsfilethatdoesntexist"
+        "--credentials-file=testing/resources/credentailsfilethatdoesntexist",
     ))
     assert ret == 2
     out, _ = capsys.readouterr()
@@ -141,6 +141,6 @@
     ret = main((
         get_resource_path('aws_config_without_secrets.ini'),
         "--credentials-file=testing/resources/credentailsfilethatdoesntexist",
-        "--allow-missing-credentials"
+        "--allow-missing-credentials",
     ))
     assert ret == 0
diff --git a/tests/file_contents_sorter_test.py b/tests/file_contents_sorter_test.py
index 2c85c8a..1f9a14b 100644
--- a/tests/file_contents_sorter_test.py
+++ b/tests/file_contents_sorter_test.py
@@ -21,7 +21,7 @@
         (b'@\n-\n_\n#\n', FAIL, b'#\n-\n@\n_\n'),
         (b'extra\n\n\nwhitespace\n', FAIL, b'extra\nwhitespace\n'),
         (b'whitespace\n\n\nextra\n', FAIL, b'extra\nwhitespace\n'),
-    )
+    ),
 )
 def test_integration(input_s, expected_retval, output, tmpdir):
     path = tmpdir.join('file.txt')
diff --git a/tests/fix_encoding_pragma_test.py b/tests/fix_encoding_pragma_test.py
index d49f1ba..7288bfa 100644
--- a/tests/fix_encoding_pragma_test.py
+++ b/tests/fix_encoding_pragma_test.py
@@ -56,7 +56,7 @@
             b'# -*- coding: utf-8 -*-\n'
             b'foo = "bar"\n'
         ),
-    )
+    ),
 )
 def test_ok_inputs(input_str):
     bytesio = io.BytesIO(input_str)
@@ -100,7 +100,7 @@
         (b'#!/usr/bin/env python\n', b''),
         (b'#!/usr/bin/env python\n#coding: utf8\n', b''),
         (b'#!/usr/bin/env python\n# -*- coding: utf-8 -*-\n', b''),
-    )
+    ),
 )
 def test_not_ok_inputs(input_str, output):
     bytesio = io.BytesIO(input_str)
diff --git a/tests/requirements_txt_fixer_test.py b/tests/requirements_txt_fixer_test.py
index 3681cc6..dcf7a76 100644
--- a/tests/requirements_txt_fixer_test.py
+++ b/tests/requirements_txt_fixer_test.py
@@ -24,9 +24,9 @@
         (
             b'-e git+ssh://git_url@tag#egg=ocflib\nDjango\nPyMySQL\n',
             FAIL,
-            b'Django\n-e git+ssh://git_url@tag#egg=ocflib\nPyMySQL\n'
+            b'Django\n-e git+ssh://git_url@tag#egg=ocflib\nPyMySQL\n',
         ),
-    )
+    ),
 )
 def test_integration(input_s, expected_retval, output, tmpdir):
     path = tmpdir.join('file.txt')
diff --git a/tests/trailing_whitespace_fixer_test.py b/tests/trailing_whitespace_fixer_test.py
index eb2a1d0..a771e67 100644
--- a/tests/trailing_whitespace_fixer_test.py
+++ b/tests/trailing_whitespace_fixer_test.py
@@ -69,7 +69,7 @@
     path = tmpdir.join(filename)
     path.write(input_s)
     ret = fix_trailing_whitespace((
-        '--markdown-linebreak-ext=TxT', path.strpath
+        '--markdown-linebreak-ext=TxT', path.strpath,
     ))
     assert ret == 1
     assert path.read() == output