Wrong verbosity level when specified in both config file and command line.

[mrolle45]

Bug Report

The verbosity level can be specified either on the command line (-v or -vv, etc.) or in the config file (verbosity = {number}). However, if specified in both places, what you get is the sum of the two levels.

To Reproduce

Place verbosity = 1 in the config file.
Call mypy -v ...

Expected Behavior

Verbosity 1, stderr shows LOG messages only.
Actual Behavior

Verbosity 2, stderr shows LOG messages and TRACE messages.

Your Environment

• Mypy version used: 0.931
• Mypy command-line flags: -v
• Mypy configuration options from mypy.ini (and other config files): verbosity = 1

How to fix the bug
This is in main.py process_options().

497    general_group.add_argument(
498        '-v', '--verbose', action='count', dest='verbosity',
499        help="More verbose messages")
923    # Parse config file first, so command line can override.
924    parse_config_file(options, set_strict_flags, config_file, stdout, stderr)
937    # Parse command line for real, using a split namespace.
938    special_opts = argparse.Namespace()
939    parser.parse_args(args, SplitNamespace(options, special_opts, 'special-opts:'))

Before line 939, save options.verbosity, then set it to 0.
After line 939, if options.verbosity is 0 (meaning -v was not present), then set it to the earlier saved value.

Note: if verbosity is specified nonzero in the config file, there is no way to override this with verbosity 0 on the command line. You could add a no-verbose command line option to accomplish this.

[mrolle45]

I have a code patch for you to use.
Applies to version 0.931.

In main.py:
492,498c492,494
<     verbose_group = parser.add_mutually_exclusive_group()
<     verbose_group.add_argument(
<         '-v', '--verbose', action='count', dest='special-opts:verbosity',
<         help="More verbose messages (cumulative, overrides 'verbosity' in config file)")
<     verbose_group.add_argument(
<         '--no-verbose', action='store_const', const=0, dest='special-opts:verbosity',
<         help="No verbose messages (overrides 'verbosity' in config file)")
---
>     general_group.add_argument(
>         '-v', '--verbose', action='count', dest='verbosity',
>         help="More verbose messages")
1032,1035d1027
<
<     # -v or --verbosity or --no-verbosity on command line overrides config file
<     if special_opts.verbosity is not None:
<         options.verbosity = special_opts.verbosity

This does two things.

1. New option --no-verbose for the command line only. Note: this option is exclusive with -v/--verbose.
2. If either -v/--verbose or --no-verbose appears on the command line, this overrides the verbosity setting in the config file. Note: -v/--verbose sets verbosity level to the number of times either option appears, and --no-verbose sets it to 0.

Please add this to your docs.

[mrolle45]

Add this to the diff, to change the 'usage' line:

293c293
< HEADER: Final = """%(prog)s [-h] [-v | --no-verbose] [-V] [more options; see below]
---
> HEADER: Final = """%(prog)s [-h] [-v] [-V] [more options; see below]

[mrolle45]

Here's the change I actually made. If you decide this is OK, please apply it to the code. The mypy - Orig directory is the 0.931 version.

The change in behavior is:

1. New --no-verbose option on the command line, mutually exclusive with -v / --verbose.
2. Better usage messages for the above.
3. Either of these options will override verbosity in the config file. -v / --verbose will use the number of appearances of either of them, and no-verbose will use 0.

*** /sp/Mypy/mypy/main.py       2022-04-30 14:01:47.638885800 -0700
--- "mypy - Orig/main.py"       2022-03-27 23:36:56.822717200 -0700
***************
*** 290,296 ****
      options.python_executable = python_executable


! HEADER: Final = """%(prog)s [-h] [-v | --no-verbose] [-V] [more options; see below]
              [-m MODULE] [-p PACKAGE] [-c PROGRAM_TEXT] [files ...]"""


--- 290,296 ----
      options.python_executable = python_executable


! HEADER: Final = """%(prog)s [-h] [-v] [-V] [more options; see below]
              [-m MODULE] [-p PACKAGE] [-c PROGRAM_TEXT] [files ...]"""


***************
*** 489,501 ****
      general_group.add_argument(
          '-h', '--help', action='help',
          help="Show this help message and exit")
!     verbose_group = general_group.add_mutually_exclusive_group()
!     verbose_group.add_argument(
!         '-v', '--verbose', action='count', dest='special-opts:verbosity',
!         help="More verbose messages (cumulative, overrides 'verbosity' in config file)")
!     verbose_group.add_argument(
!         '--no-verbose', action='store_const', const=0, dest='special-opts:verbosity',
!         help="No verbose messages (overrides 'verbosity' in config file)")
      general_group.add_argument(
          '-V', '--version', action=CapturableVersionAction,
          version='%(prog)s ' + __version__,
--- 489,497 ----
      general_group.add_argument(
          '-h', '--help', action='help',
          help="Show this help message and exit")
!     general_group.add_argument(
!         '-v', '--verbose', action='count', dest='verbosity',
!         help="More verbose messages")
      general_group.add_argument(
          '-V', '--version', action=CapturableVersionAction,
          version='%(prog)s ' + __version__,
***************
*** 1030,1039 ****
      if options.logical_deps:
          options.cache_fine_grained = True

-     # -v or --verbose or --no-verbose on command line overrides config file
-     if special_opts.verbosity is not None:
-         options.verbosity = special_opts.verbosity
-
      # Set target.
      if special_opts.modules + special_opts.packages:
          options.build_type = BuildType.MODULE
--- 1026,1031 ----