double-quote-string-fixer
diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 4990537..55c6f73 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -10,6 +10,7 @@
     -   id: check-yaml
     -   id: debug-statements
     -   id: name-tests-test
+    -   id: double-quote-string-fixer
     -   id: requirements-txt-fixer
 -   repo: https://gitlab.com/pycqa/flake8
     rev: 3.7.1
diff --git a/pre_commit_hooks/fix_encoding_pragma.py b/pre_commit_hooks/fix_encoding_pragma.py
index dbe9c6c..bde4e78 100644
--- a/pre_commit_hooks/fix_encoding_pragma.py
+++ b/pre_commit_hooks/fix_encoding_pragma.py
@@ -147,5 +147,5 @@
     return retv
 
 
-if __name__ == "__main__":
+if __name__ == '__main__':
     exit(main())
diff --git a/pre_commit_hooks/sort_simple_yaml.py b/pre_commit_hooks/sort_simple_yaml.py
index 3c8ef16..a381679 100755
--- a/pre_commit_hooks/sort_simple_yaml.py
+++ b/pre_commit_hooks/sort_simple_yaml.py
@@ -115,9 +115,9 @@
             new_lines = sort(lines)
 
             if lines != new_lines:
-                print("Fixing file `{filename}`".format(filename=filename))
+                print('Fixing file `{filename}`'.format(filename=filename))
                 f.seek(0)
-                f.write("\n".join(new_lines) + "\n")
+                f.write('\n'.join(new_lines) + '\n')
                 f.truncate()
                 retval = 1
 
diff --git a/pre_commit_hooks/trailing_whitespace_fixer.py b/pre_commit_hooks/trailing_whitespace_fixer.py
index b2b6418..2ccc003 100644
--- a/pre_commit_hooks/trailing_whitespace_fixer.py
+++ b/pre_commit_hooks/trailing_whitespace_fixer.py
@@ -69,7 +69,7 @@
     for ext in md_exts:
         if any(c in ext[1:] for c in r'./\:'):
             parser.error(
-                "bad --markdown-linebreak-ext extension {!r} (has . / \\ :)\n"
+                'bad --markdown-linebreak-ext extension {!r} (has . / \\ :)\n'
                 "  (probably filename; use '--markdown-linebreak-ext=EXT')"
                 .format(ext),
             )
diff --git a/tests/check_builtin_literals_test.py b/tests/check_builtin_literals_test.py
index dbb9cc4..19263b7 100644
--- a/tests/check_builtin_literals_test.py
+++ b/tests/check_builtin_literals_test.py
@@ -47,36 +47,36 @@
         # see #285
         ('x[0]()', []),
         # complex
-        ("0j", []),
-        ("complex()", [Call('complex', 1, 0)]),
-        ("complex(0, 0)", []),
+        ('0j', []),
+        ('complex()', [Call('complex', 1, 0)]),
+        ('complex(0, 0)', []),
         ("complex('0+0j')", []),
         ('builtins.complex()', []),
         # float
-        ("0.0", []),
-        ("float()", [Call('float', 1, 0)]),
+        ('0.0', []),
+        ('float()', [Call('float', 1, 0)]),
         ("float('0.0')", []),
         ('builtins.float()', []),
         # int
-        ("0", []),
-        ("int()", [Call('int', 1, 0)]),
+        ('0', []),
+        ('int()', [Call('int', 1, 0)]),
         ("int('0')", []),
         ('builtins.int()', []),
         # list
-        ("[]", []),
-        ("list()", [Call('list', 1, 0)]),
+        ('[]', []),
+        ('list()', [Call('list', 1, 0)]),
         ("list('abc')", []),
         ("list([c for c in 'abc'])", []),
         ("list(c for c in 'abc')", []),
         ('builtins.list()', []),
         # str
         ("''", []),
-        ("str()", [Call('str', 1, 0)]),
+        ('str()', [Call('str', 1, 0)]),
         ("str('0')", []),
         ('builtins.str()', []),
         # tuple
-        ("()", []),
-        ("tuple()", [Call('tuple', 1, 0)]),
+        ('()', []),
+        ('tuple()', [Call('tuple', 1, 0)]),
         ("tuple('abc')", []),
         ("tuple([c for c in 'abc'])", []),
         ("tuple(c for c in 'abc')", []),
@@ -91,9 +91,9 @@
 @pytest.mark.parametrize(
     ('expression', 'calls'),
     [
-        ("{}", []),
-        ("dict()", [Call('dict', 1, 0)]),
-        ("dict(a=1, b=2, c=3)", []),
+        ('{}', []),
+        ('dict()', [Call('dict', 1, 0)]),
+        ('dict(a=1, b=2, c=3)', []),
         ("dict(**{'a': 1, 'b': 2, 'c': 3})", []),
         ("dict([(k, v) for k, v in [('a', 1), ('b', 2), ('c', 3)]])", []),
         ("dict((k, v) for k, v in [('a', 1), ('b', 2), ('c', 3)])", []),
@@ -108,8 +108,8 @@
 @pytest.mark.parametrize(
     ('expression', 'calls'),
     [
-        ("dict()", [Call('dict', 1, 0)]),
-        ("dict(a=1, b=2, c=3)", [Call('dict', 1, 0)]),
+        ('dict()', [Call('dict', 1, 0)]),
+        ('dict(a=1, b=2, c=3)', [Call('dict', 1, 0)]),
         ("dict(**{'a': 1, 'b': 2, 'c': 3})", [Call('dict', 1, 0)]),
         ('builtins.dict()', []),
     ],
diff --git a/tests/detect_aws_credentials_test.py b/tests/detect_aws_credentials_test.py
index 31ba33e..777fb48 100644
--- a/tests/detect_aws_credentials_test.py
+++ b/tests/detect_aws_credentials_test.py
@@ -123,7 +123,7 @@
     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()
@@ -143,7 +143,7 @@
     mock_secrets_file.return_value = set()
     ret = main((
         get_resource_path('aws_config_without_secrets.ini'),
-        "--credentials-file=testing/resources/credentailsfilethatdoesntexist",
-        "--allow-missing-credentials",
+        '--credentials-file=testing/resources/credentailsfilethatdoesntexist',
+        '--allow-missing-credentials',
     ))
     assert ret == 0
diff --git a/tests/pretty_format_json_test.py b/tests/pretty_format_json_test.py
index bf7a16f..3b7b9a2 100644
--- a/tests/pretty_format_json_test.py
+++ b/tests/pretty_format_json_test.py
@@ -41,7 +41,7 @@
     assert ret == expected_retval
 
 
-@pytest.mark.skipif(PY2, reason="Requires Python3")
+@pytest.mark.skipif(PY2, reason='Requires Python3')
 @pytest.mark.parametrize(
     ('filename', 'expected_retval'), (
         ('not_pretty_formatted_json.json', 1),
diff --git a/tests/sort_simple_yaml_test.py b/tests/sort_simple_yaml_test.py
index 72f5bec..4261d5d 100644
--- a/tests/sort_simple_yaml_test.py
+++ b/tests/sort_simple_yaml_test.py
@@ -45,7 +45,7 @@
     file_path = os.path.join(tmpdir.strpath, 'foo.yaml')
 
     with open(file_path, 'w') as f:
-        f.write("\n".join(bad_lines) + "\n")
+        f.write('\n'.join(bad_lines) + '\n')
 
     assert main([file_path]) == retval