Commit eb82fb0a authored by Loic Bistuer's avatar Loic Bistuer
Browse files

Refactored color_style() and no_style() to improve testability. Refs #23663. 

This includes the following improvements:

- The type of the style object is now called 'Style' rather than 'dummy'.
- The new make_style() function allows generating a Style object directly
  from a config string. Before the only way to get a style object was
  through the environ and it also required that the terminal supported
  colors which isn't necessarily the case when testing.
- The output of no_style() is now cached with @lru_cache.
- The output of no_style() now has the same set of attributes as the
  other Style objects. Previously it allowed anything to pass through
  with __getattr__.
parent bdb4118b

django/core/management/color.py

+45 −29
Original line number Diff line number Diff line
@@ -5,17 +5,18 @@ Sets up the terminal color scheme. 
import os

import sys



from django.utils import lru_cache

from django.utils import termcolors





def supports_color():

    """

    Returns True if the running system's terminal supports color, and False

    otherwise.

    Returns True if the running system's terminal supports color,

    and False otherwise.

    """

    plat = sys.platform

    supported_platform = plat != 'Pocket PC' and (plat != 'win32' or

                                                  'ANSICON' in os.environ)

    supported_platform = plat != 'Pocket PC' and (plat != 'win32' or 'ANSICON' in os.environ)



    # isatty is not always implemented, #6223.

    is_a_tty = hasattr(sys.stdout, 'isatty') and sys.stdout.isatty()

    if not supported_platform or not is_a_tty:
@@ -23,34 +24,49 @@ def supports_color(): 
    return True





def color_style():

    """Returns a Style object with the Django color scheme."""

    if not supports_color():

        style = no_style()

    else:

        DJANGO_COLORS = os.environ.get('DJANGO_COLORS', '')

        color_settings = termcolors.parse_color_setting(DJANGO_COLORS)

        if color_settings:

            class dummy:

def make_style(config_string=''):

    """

    Create a Style object from the given config_string.



    If config_string is empty django.utils.termcolors.DEFAULT_PALETTE is used.

    """

    class Style(object):

        pass

            style = dummy()



    style = Style()



    color_settings = termcolors.parse_color_setting(config_string)



    # The nocolor palette has all available roles.

    # Use that palette as the basis for populating

    # the palette as defined in the environment.

    for role in termcolors.PALETTES[termcolors.NOCOLOR_PALETTE]:

        if color_settings:

            format = color_settings.get(role, {})

                setattr(style, role, termcolors.make_style(**format))

            style_func = termcolors.make_style(**format)

        else:

            style_func = lambda x: x

        setattr(style, role, style_func)



    # For backwards compatibility,

    # set style for ERROR_OUTPUT == ERROR

    style.ERROR_OUTPUT = style.ERROR

        else:

            style = no_style()



    return style





@lru_cache.lru_cache(maxsize=None)

def no_style():

    """Returns a Style object that has no colors."""

    class dummy:

        def __getattr__(self, attr):

            return lambda x: x

    return dummy()
 
    """

    Returns a Style object with no color scheme.

    """

    return make_style('nocolor')





def color_style():

    """

    Returns a Style object from the Django color scheme.

    """

    if not supports_color():

        return no_style()

    return make_style(os.environ.get('DJANGO_COLORS', ''))

tests/admin_scripts/tests.py

+16 −0
Original line number Diff line number Diff line
@@ -1392,6 +1392,22 @@ class CommandTypes(AdminScriptTestCase): 
        self.assertOutput(out, "Prints the CREATE TABLE, custom SQL and CREATE INDEX SQL statements for the\ngiven model module name(s).")

        self.assertEqual(out.count('optional arguments'), 1)



    def test_color_style(self):

        style = color.no_style()

        self.assertEqual(style.ERROR('Hello, world!'), 'Hello, world!')



        style = color.make_style('nocolor')

        self.assertEqual(style.ERROR('Hello, world!'), 'Hello, world!')



        style = color.make_style('dark')

        self.assertIn('Hello, world!', style.ERROR('Hello, world!'))

        self.assertNotEqual(style.ERROR('Hello, world!'), 'Hello, world!')



        # Default palette has color.

        style = color.make_style('')

        self.assertIn('Hello, world!', style.ERROR('Hello, world!'))

        self.assertNotEqual(style.ERROR('Hello, world!'), 'Hello, world!')



    def test_command_color(self):

        class Command(BaseCommand):

            requires_system_checks = False