Disable color if TERM=dumb is detected

pre_commit/color.py

@@ -49,6 +49,10 @@ def use_color(setting):
  raise InvalidColorSetting(setting)
 
  return (
- setting == 'always' or
- (setting == 'auto' and sys.stdout.isatty() and terminal_supports_color)
+ setting == 'always' or (
+ setting == 'auto' and
+ sys.stdout.isatty() and
+ terminal_supports_color and
+ os.getenv('TERM') != 'dumb'
+ )
  )

tests/color_test.py

@@ -5,6 +5,7 @@
 import mock
 import pytest
 
+from pre_commit import envcontext
 from pre_commit.color import format_color
 from pre_commit.color import GREEN
 from pre_commit.color import InvalidColorSetting
@@ -38,13 +39,22 @@ def test_use_color_no_tty():
 def test_use_color_tty_with_color_support():
  with mock.patch.object(sys.stdout, 'isatty', return_value=True):
  with mock.patch('pre_commit.color.terminal_supports_color', True):
- assert use_color('auto') is True
+ with envcontext.envcontext([('TERM', envcontext.UNSET)]):
+ assert use_color('auto') is True
 
 
 def test_use_color_tty_without_color_support():
  with mock.patch.object(sys.stdout, 'isatty', return_value=True):
  with mock.patch('pre_commit.color.terminal_supports_color', False):
- assert use_color('auto') is False
+ with envcontext.envcontext([('TERM', envcontext.UNSET)]):
+ assert use_color('auto') is False
+
+
+def test_use_color_dumb_term():
+ with mock.patch.object(sys.stdout, 'isatty', return_value=True):
+ with mock.patch('pre_commit.color.terminal_supports_color', True):
+ with envcontext.envcontext([('TERM', 'dumb')]):
+ assert use_color('auto') is False
 
 
 def test_use_color_raises_if_given_shenanigans():