Merge pull request #86 from gforcada/builtins-whitelist

Builtins ignorelist

CHANGES.rst

@@ -18,6 +18,8 @@ Changelog
 
 - Overhaul GitHub actions to test on actual supported python versions. [gforcada]
 
+- New flake8 option `--builtins-ignorelist` to specify a list of builtins to ignore. [gsingh93]
+
 1.5.3 (2020-05-14)
 ------------------
 

README.rst

@@ -73,6 +73,14 @@ Install with pip::
 
     $ pip install flake8-builtins
 
+Options
+-------
+
+One can use `--builtins-ignorelist` option, or configuration option,
+to ignore a custom list of builtins::
+
+    $ flake8 --builtins-ignorelist id,copyright *.py
+
 Requirements
 ------------
 - Python 3.7, 3.8, 3.9

flake8_builtins.py

@@ -5,15 +5,16 @@
 
 from flake8 import utils as stdin_utils
 
-WHITE_LIST = {
+IGNORE_LIST = {
     '__name__',
     '__doc__',
     'credits',
     '_',
 }
 
 
-BUILTINS = [a[0] for a in inspect.getmembers(builtins) if a[0] not in WHITE_LIST]
+# Will be initialized in `BuiltinsChecker.parse_options`
+BUILTINS = None
 
 if sys.version_info >= (3, 8):
     NamedExpr = ast.NamedExpr
@@ -32,6 +33,25 @@ def __init__(self, tree, filename):
         self.tree = tree
         self.filename = filename
 
+    def add_options(option_manager):
+        option_manager.add_option(
+            '--builtins-ignorelist',
+            metavar='builtins',
+            parse_from_config=True,
+            comma_separated_list=True,
+            help='A comma separated list of builtins to skip checking',
+        )
+
+    def parse_options(option_manager, options, args):
+        global BUILTINS
+
+        if options.builtins_ignorelist is not None:
+            IGNORE_LIST.update(options.builtins_ignorelist)
+
+        BUILTINS = [
+            a[0] for a in inspect.getmembers(builtins) if a[0] not in IGNORE_LIST
+        ]
+
     def run(self):
         tree = self.tree
 

run_tests.py

@@ -9,19 +9,33 @@
 from flake8_builtins import BuiltinsChecker
 
 
+class FakeOptions:
+    builtins_ignorelist = []
+
+    def __init__(self, ignore_list=''):
+        if ignore_list:
+            self.builtins_ignorelist = ignore_list
+
+
 class TestBuiltins(unittest.TestCase):
-    def check_code(self, source, expected_codes=None):
+    def check_code(self, source, expected_codes=None, ignore_list=None):
         """Check if the given source code generates the given flake8 errors
 
         If `expected_codes` is a string is converted to a list,
         if it is not given, then it is expected to **not** generate any error.
+
+        If `ignore_list` is provided, it should be a list of names
+        that will be ignored if found, as if they were a builtin.
         """
         if isinstance(expected_codes, str):
             expected_codes = [expected_codes]
         elif expected_codes is None:
             expected_codes = []
+        if ignore_list is None:
+            ignore_list = []
         tree = ast.parse(textwrap.dedent(source))
         checker = BuiltinsChecker(tree, '/home/script.py')
+        checker.parse_options(FakeOptions(ignore_list=ignore_list), None)
         return_statements = list(checker.run())
 
         self.assertEqual(
@@ -169,13 +183,17 @@ def bla():
         """
         self.check_code(source, ['A001', 'A001'])
 
-    def test_ignore_whitelisted_names(self):
+    def test_default_ignored_names(self):
         source = """
         class MyClass(object):
             __name__ = 4
         """
         self.check_code(source)
 
+    def test_custom_ignored_names(self):
+        source = 'copyright = 4'
+        self.check_code(source, ignore_list=('copyright',))
+
     def test_for_loop_variable(self):
         source = """
         for format in (1, 2, 3):