Allow disabling color

knack/arguments.py

@@ -265,6 +265,7 @@ def _get_preview_arg_message(self):
             object_type = 'positional argument'
 
         preview_info = PreviewItem(
+            cli_ctx=self.command_loader.cli_ctx,
             target=target,
             object_type=object_type,
             message_func=_get_preview_arg_message

knack/cli.py

@@ -91,6 +91,7 @@ def __init__(self,
         self.output = self.output_cls(cli_ctx=self)
         self.result = None
         self.query = query_cls(cli_ctx=self)
+        self.enable_color = not self.config.get('core', 'no_color', fallback=False)
 
     @staticmethod
     def _should_show_version(args):
@@ -187,6 +188,13 @@ def invoke(self, args, initial_invocation_data=None, out_file=None):
             raise TypeError('args should be a list or tuple.')
         exit_code = 0
         try:
+            if self.enable_color:
+                import colorama
+                colorama.init()
+                if self.out_file == sys.__stdout__:
+                    # point out_file to the new sys.stdout which is overwritten by colorama
+                    self.out_file = sys.stdout
+
             args = self.completion.get_completion_args() or args
             out_file = out_file or self.out_file
 
@@ -218,6 +226,7 @@ def invoke(self, args, initial_invocation_data=None, out_file=None):
             exit_code = self.exception_handler(ex)
             self.result = CommandResultItem(None, error=ex)
         finally:
-            pass
+            if self.enable_color:
+                colorama.deinit()
         self.result.exit_code = exit_code
         return exit_code

knack/commands.py

@@ -302,6 +302,7 @@ def __init__(self, command_loader, group_name, operations_tmpl, **kwargs):
             kwargs['deprecate_info'].target = group_name
         if kwargs.get('is_preview', False):
             kwargs['preview_info'] = PreviewItem(
+                cli_ctx=self.command_loader.cli_ctx,
                 target=group_name,
                 object_type='command group'
             )

knack/help.py

@@ -684,8 +684,6 @@ def show_welcome(self, parser):
         self.print_description_list(help_file.children)
 
     def show_help(self, cli_name, nouns, parser, is_group):
-        import colorama
-        colorama.init(autoreset=True)
         delimiters = ' '.join(nouns)
         help_file = self.command_help_cls(self, delimiters, parser) if not is_group \
             else self.group_help_cls(self, delimiters, parser)

knack/invocation.py

@@ -127,7 +127,6 @@ def execute(self, args):
         :return: The command result
         :rtype: knack.util.CommandResultItem
         """
-        import colorama
 
         self.cli_ctx.raise_event(EVENT_INVOKER_PRE_CMD_TBL_CREATE, args=args)
         cmd_tbl = self.commands_loader.load_command_table(args)
@@ -198,12 +197,10 @@ def execute(self, args):
             preview_kwargs['object_type'] = 'command'
             previews.append(ImplicitPreviewItem(**preview_kwargs))
 
-        colorama.init()
         for d in deprecations:
             print(d.message, file=sys.stderr)
         for p in previews:
             print(p.message, file=sys.stderr)
-        colorama.deinit()
 
         cmd_result = parsed_args.func(params)
         cmd_result = todict(cmd_result)

knack/log.py

@@ -54,24 +54,10 @@ def wrap_msg_with_color(msg):
 
         return cls.COLOR_MAP.get(level, None)
 
-    def _should_enable_color(self):
-        try:
-            # Color if tty stream available
-            if self.stream.isatty():
-                return True
-        except AttributeError:
-            pass
-        return False
-
-    def __init__(self, log_level_config, log_format):
-        import platform
-        import colorama
-
+    def __init__(self, log_level_config, log_format, enable_color):
         logging.StreamHandler.__init__(self)
         self.setLevel(log_level_config)
-        if platform.system() == 'Windows':
-            self.stream = colorama.AnsiToWin32(self.stream).stream
-        self.enable_color = self._should_enable_color()
+        self.enable_color = enable_color
         self.setFormatter(logging.Formatter(log_format[self.enable_color]))
 
     def format(self, record):
@@ -153,9 +139,11 @@ def _determine_verbose_level(self, args):
 
     def _init_console_handlers(self, root_logger, cli_logger, log_level_config):
         root_logger.addHandler(_CustomStreamHandler(log_level_config['root'],
-                                                    self.console_log_format['root']))
+                                                    self.console_log_format['root'],
+                                                    self.cli_ctx.enable_color))
         cli_logger.addHandler(_CustomStreamHandler(log_level_config[CLI_LOGGER_NAME],
-                                                   self.console_log_format[CLI_LOGGER_NAME]))
+                                                   self.console_log_format[CLI_LOGGER_NAME],
+                                                   self.cli_ctx.enable_color))
 
     def _init_logfile_handlers(self, root_logger, cli_logger):
         ensure_dir(self.log_dir)

knack/output.py

@@ -146,11 +146,6 @@ def out(self, obj, formatter=None, out_file=None):  # pylint: disable=no-self-us
         if not isinstance(obj, CommandResultItem):
             raise TypeError('Expected {} got {}'.format(CommandResultItem.__name__, type(obj)))
 
-        import platform
-        import colorama
-
-        if platform.system() == 'Windows':
-            out_file = colorama.AnsiToWin32(out_file).stream
         output = formatter(obj)
         try:
             print(output, file=out_file, end='')

knack/preview.py

@@ -32,7 +32,7 @@ def _get_command_group(name):
 # pylint: disable=too-many-instance-attributes
 class PreviewItem(StatusTag):
 
-    def __init__(self, cli_ctx=None, object_type='', target=None, tag_func=None, message_func=None, **kwargs):
+    def __init__(self, cli_ctx, object_type='', target=None, tag_func=None, message_func=None, **kwargs):
         """ Create a collection of preview metadata.
 
         :param cli_ctx: The CLI context associated with the preview item.

knack/util.py

@@ -9,6 +9,8 @@
 from datetime import date, time, datetime, timedelta
 from enum import Enum
 
+NO_COLOR_VARIABLE_NAME = 'KNACK_NO_COLOR'
+
 
 class CommandResultItem(object):  # pylint: disable=too-few-public-methods
     def __init__(self, result, table_transformer=None, is_query_active=False,
@@ -90,12 +92,13 @@ def show_in_help(self):
     @property
     def tag(self):
         """ Returns a tag object. """
-        return ColorizedString(self._get_tag(self), self._color)
+        return ColorizedString(self._get_tag(self), self._color) if self.cli_ctx.enable_color else self._get_tag(self)
 
     @property
     def message(self):
         """ Returns a tuple with the formatted message string and the message length. """
-        return ColorizedString(self._get_message(self), self._color)
+        return ColorizedString(self._get_message(self), self._color) if self.cli_ctx.enable_color \
+            else "WARNING: " + self._get_message(self)
 
 
 def ensure_dir(d):

tests/test_deprecation.py

@@ -15,7 +15,7 @@
 from knack.arguments import ArgumentsContext
 from knack.commands import CLICommand, CLICommandsLoader, CommandGroup
 
-from tests.util import DummyCLI, redirect_io
+from tests.util import DummyCLI, redirect_io, disable_color
 
 
 def example_handler(arg1, arg2=None, arg3=None):
@@ -128,13 +128,32 @@ def test_deprecate_command_expiring_execute(self):
         expected = "This command has been deprecated and will be removed in version '1.0.0'. Use 'alt-cmd4' instead."
         self.assertIn(expected, actual)
 
+    @redirect_io
+    def test_deprecate_command_expiring_execute_no_color(self):
+        """ Ensure warning is displayed without color. """
+        self.cli_ctx.enable_color = False
+        self.cli_ctx.invoke('cmd4 -b b'.split())
+        actual = self.io.getvalue()
+        expected = "WARNING: This command has been deprecated and will be removed in version '1.0.0'"
+        self.assertIn(expected, actual)
+
     @redirect_io
     def test_deprecate_command_expired_execute(self):
         """ Ensure expired command cannot be reached. """
         with self.assertRaises(SystemExit):
             self.cli_ctx.invoke('cmd5 -h'.split())
         actual = self.io.getvalue()
-        expected = """The most similar choices to 'cmd5'"""
+        expected = """cli: 'cmd5' is not in the 'cli' command group."""
+        self.assertIn(expected, actual)
+
+    @redirect_io
+    @disable_color
+    def test_deprecate_command_expired_execute_no_color(self):
+        """ Ensure error is displayed without color. """
+        with self.assertRaises(SystemExit):
+            self.cli_ctx.invoke('cmd5 -h'.split())
+        actual = self.io.getvalue()
+        expected = """ERROR: cli: 'cmd5' is not in the 'cli' command group."""
         self.assertIn(expected, actual)
 
 
@@ -228,6 +247,21 @@ def test_deprecate_command_group_help_expiring(self):
 """.format(self.cli_ctx.name)
         self.assertIn(expected, actual)
 
+    @redirect_io
+    @disable_color
+    def test_deprecate_command_group_help_expiring_no_color(self):
+        """ Ensure warning is displayed without color. """
+        with self.assertRaises(SystemExit):
+            self.cli_ctx.invoke('group4 -h'.split())
+        actual = self.io.getvalue()
+        expected = """
+Group
+    cli group4
+        WARNING: This command group has been deprecated and will be removed in version \'1.0.0\'. Use
+        'alt-group4' instead.
+""".format(self.cli_ctx.name)
+        self.assertIn(expected, actual)
+
     @redirect_io
     def test_deprecate_command_group_expired(self):
         """ Ensure expired command cannot be reached. """
@@ -411,6 +445,15 @@ def test_deprecate_options_execute_expiring(self):
         expected = "Option '--alt4' has been deprecated and will be removed in version '1.0.0'. Use '--opt4' instead."
         self.assertIn(expected, actual)
 
+    @redirect_io
+    @disable_color
+    def test_deprecate_options_execute_expiring_no_color(self):
+        """ Ensure error is displayed without color. """
+        self.cli_ctx.invoke('arg-test --arg1 foo --opt1 bar --alt4 bar'.split())
+        actual = self.io.getvalue()
+        expected = "WARNING: Option '--alt4' has been deprecated and will be removed in version '1.0.0'. Use '--opt4' instead."
+        self.assertIn(expected, actual)
+
     @redirect_io
     def test_deprecate_options_execute_expiring_non_deprecated(self):
         """ Ensure non-expiring options can be used without warning. """

tests/test_preview.py

@@ -5,6 +5,7 @@
 
 from __future__ import unicode_literals, print_function
 
+import os
 import unittest
 try:
     import mock
@@ -17,7 +18,7 @@
 from knack.arguments import ArgumentsContext
 from knack.commands import CLICommandsLoader, CommandGroup
 
-from tests.util import DummyCLI, redirect_io
+from tests.util import DummyCLI, redirect_io, disable_color
 
 
 def example_handler(arg1, arg2=None, arg3=None):
@@ -87,6 +88,31 @@ def test_preview_command_plain_execute(self):
         expected = "This command is in preview. It may be changed/removed in a future release."
         self.assertIn(expected, actual)
 
+    @redirect_io
+    @disable_color
+    def test_preview_command_plain_execute_no_color(self):
+        """ Ensure warning is displayed without color. """
+        self.cli_ctx.invoke('cmd1 -b b'.split())
+        actual = self.io.getvalue()
+        self.assertIn("WARNING: This command is in preview. It may be changed/removed in a future release.", actual)
+
+    @redirect_io
+    def test_preview_command_implicitly_execute(self):
+        """ Ensure general warning displayed when running command from a preview parent group. """
+        self.cli_ctx.invoke('grp1 cmd1 -b b'.split())
+        actual = self.io.getvalue()
+        expected = "Command group 'grp1' is in preview. It may be changed/removed in a future release."
+        self.assertIn(expected, actual)
+
+    @redirect_io
+    @disable_color
+    def test_preview_command_implicitly_no_color(self):
+        """ Ensure warning is displayed without color. """
+        self.cli_ctx.invoke('grp1 cmd1 -b b'.split())
+        actual = self.io.getvalue()
+        expected = "WARNING: Command group 'grp1' is in preview. It may be changed/removed in a future release."
+        self.assertIn(expected, actual)
+
 
 class TestCommandGroupPreview(unittest.TestCase):
 
@@ -129,6 +155,23 @@ def test_preview_command_group_help_plain(self):
 Commands:
     cmd1 : Short summary here.
 
+""".format(self.cli_ctx.name)
+        self.assertEqual(expected, actual)
+
+    @redirect_io
+    @disable_color
+    def test_preview_command_group_help_plain_no_color(self):
+        """ Ensure warning is displayed without color. """
+        with self.assertRaises(SystemExit):
+            self.cli_ctx.invoke('group1 -h'.split())
+        actual = self.io.getvalue()
+        expected = """
+Group
+    cli group1 : A group.
+        WARNING: This command group is in preview. It may be changed/removed in a future release.
+Commands:
+    cmd1 : Short summary here.
+
 """.format(self.cli_ctx.name)
         self.assertEqual(expected, actual)
 
@@ -190,6 +233,20 @@ def test_preview_arguments_command_help(self):
 """.format(self.cli_ctx.name)
         self.assertIn(expected, actual)
 
+    @redirect_io
+    @disable_color
+    def test_preview_arguments_command_help_no_color(self):
+        """ Ensure warning is displayed without color. """
+        with self.assertRaises(SystemExit):
+            self.cli_ctx.invoke('arg-test -h'.split())
+        actual = self.io.getvalue()
+        expected = """
+Arguments
+    --arg1 [Preview] [Required] : Arg1.
+        WARNING: Argument '--arg1' is in preview. It may be changed/removed in a future release.
+""".format(self.cli_ctx.name)
+        self.assertIn(expected, actual)
+
     @redirect_io
     def test_preview_arguments_execute(self):
         """ Ensure deprecated arguments can be used. """
@@ -201,6 +258,18 @@ def test_preview_arguments_execute(self):
         action_expected = "Side-effect from some original action!"
         self.assertIn(action_expected, actual)
 
+    @redirect_io
+    @disable_color
+    def test_preview_arguments_execute_no_color(self):
+        """ Ensure warning is displayed without color. """
+        self.cli_ctx.invoke('arg-test --arg1 foo --opt1 bar'.split())
+        actual = self.io.getvalue()
+        preview_expected = "WARNING: Argument '--arg1' is in preview. It may be changed/removed in a future release."
+        self.assertIn(preview_expected, actual)
+
+        action_expected = "Side-effect from some original action!"
+        self.assertIn(action_expected, actual)
+
 
 if __name__ == '__main__':
     unittest.main()

tests/util.py

@@ -12,6 +12,8 @@
 import shutil
 import os
 from six import StringIO
+import logging
+from knack.log import CLI_LOGGER_NAME
 
 from knack.cli import CLI, CLICommandsLoader, CommandInvoker
 
@@ -29,6 +31,21 @@ def wrapper(self):
         self.io.close()
         sys.stdout = original_stderr
         sys.stderr = original_stderr
+
+        # Remove the handlers added by CLI, so that the next invoke call init them again with the new stderr
+        # Otherwise, the handlers will write to a closed StringIO from a preview test
+        root_logger = logging.getLogger()
+        cli_logger = logging.getLogger(CLI_LOGGER_NAME)
+        root_logger.handlers = root_logger.handlers[:-1]
+        cli_logger.handlers = cli_logger.handlers[:-1]
+    return wrapper
+
+
+def disable_color(func):
+    def wrapper(self):
+        self.cli_ctx.enable_color = False
+        func(self)
+        self.cli_ctx.enable_color = True
     return wrapper