Re: [PATCH v6 05/23] dts: settings docstring update

["Juraj Linkeš" <juraj.linkes@pantheon.tech>]

On Wed, Nov 8, 2023 at 5:17 PM Yoan Picchi <yoan.picchi@foss.arm.com> wrote:
>
> On 11/8/23 12:53, Juraj Linkeš wrote:
> > Format according to the Google format and PEP257, with slight
> > deviations.
> >
> > Signed-off-by: Juraj Linkeš <juraj.linkes@pantheon.tech>
> > ---
> >   dts/framework/settings.py | 101 +++++++++++++++++++++++++++++++++++++-
> >   1 file changed, 100 insertions(+), 1 deletion(-)
> >
> > diff --git a/dts/framework/settings.py b/dts/framework/settings.py
> > index 7f5841d073..787db7c198 100644
> > --- a/dts/framework/settings.py
> > +++ b/dts/framework/settings.py
> > @@ -3,6 +3,70 @@
> >   # Copyright(c) 2022-2023 PANTHEON.tech s.r.o.
> >   # Copyright(c) 2022 University of New Hampshire
> >
> > +"""Environment variables and command line arguments parsing.
> > +
> > +This is a simple module utilizing the built-in argparse module to parse command line arguments,
> > +augment them with values from environment variables and make them available across the framework.
> > +
> > +The command line value takes precedence, followed by the environment variable value,
> > +followed by the default value defined in this module.
> > +
> > +The command line arguments along with the supported environment variables are:
> > +
> > +.. option:: --config-file
> > +.. envvar:: DTS_CFG_FILE
> > +
> > +    The path to the YAML test run configuration file.
> > +
> > +.. option:: --output-dir, --output
> > +.. envvar:: DTS_OUTPUT_DIR
> > +
> > +    The directory where DTS logs and results are saved.
> > +
> > +.. option:: --compile-timeout
> > +.. envvar:: DTS_COMPILE_TIMEOUT
> > +
> > +    The timeout for compiling DPDK.
> > +
> > +.. option:: -t, --timeout
> > +.. envvar:: DTS_TIMEOUT
> > +
> > +    The timeout for all DTS operation except for compiling DPDK.
> > +
> > +.. option:: -v, --verbose
> > +.. envvar:: DTS_VERBOSE
> > +
> > +    Set to any value to enable logging everything to the console.
> > +
> > +.. option:: -s, --skip-setup
> > +.. envvar:: DTS_SKIP_SETUP
> > +
> > +    Set to any value to skip building DPDK.
> > +
> > +.. option:: --tarball, --snapshot, --git-ref
> > +.. envvar:: DTS_DPDK_TARBALL
> > +
> > +    The path to a DPDK tarball, git commit ID, tag ID or tree ID to test.
> > +
> > +.. option:: --test-cases
> > +.. envvar:: DTS_TESTCASES
> > +
> > +    A comma-separated list of test cases to execute. Unknown test cases will be silently ignored.
> > +
> > +.. option:: --re-run, --re_run
> > +.. envvar:: DTS_RERUN
> > +
> > +    Re-run each test case this many times in case of a failure.
> > +
> > +Attributes:
> > +    SETTINGS: The module level variable storing framework-wide DTS settings.
>
> In the generated doc, "Attributes" doesn't appear. It ends up looking
> like SETTINGS is just another environment variable, with no separation
> with the above list.
>

Yes, the Attributes: section is just a syntactical way to tell the
parser to render the attributes in a certain way.
We could add some delimiter or an extra paragraph explaining that what
comes next are module attributes. I'll try to add something.

> > +
> > +Typical usage example::
> > +
> > +  from framework.settings import SETTINGS
> > +  foo = SETTINGS.foo
> > +"""
> > +
> >   import argparse
> >   import os
> >   from collections.abc import Callable, Iterable, Sequence
> > @@ -16,6 +80,23 @@
> >
> >
> >   def _env_arg(env_var: str) -> Any:
> > +    """A helper method augmenting the argparse Action with environment variable
> > +
> > +    If the supplied environment variable is defined, then the default value
> > +    of the argument is modified. This satisfies the priority order of
> > +    command line argument > environment variable > default value.
> > +
> > +    Arguments with no values (flags) should be defined using the const keyword argument
> > +    (True or False). When the argument is specified, it will be set to const, if not specified,
> > +    the default will be stored (possibly modified by the corresponding environment variable).
> > +
> > +    Other arguments work the same as default argparse arguments, that is using
> > +    the default 'store' action.
> > +
> > +    Returns:
> > +          The modified argparse.Action.
> > +    """
> > +
> >       class _EnvironmentArgument(argparse.Action):
> >           def __init__(
> >               self,
> > @@ -68,14 +149,28 @@ def __call__(
> >
> >   @dataclass(slots=True)
> >   class Settings:
> > +    """Default framework-wide user settings.
> > +
> > +    The defaults may be modified at the start of the run.
> > +    """
> > +
> > +    #:
> >       config_file_path: Path = Path(__file__).parent.parent.joinpath("conf.yaml")
> > +    #:
> >       output_dir: str = "output"
> > +    #:
> >       timeout: float = 15
> > +    #:
> >       verbose: bool = False
> > +    #:
> >       skip_setup: bool = False
> > +    #:
> >       dpdk_tarball_path: Path | str = "dpdk.tar.xz"
> > +    #:
> >       compile_timeout: float = 1200
> > +    #:
> >       test_cases: list[str] = field(default_factory=list)
> > +    #:
> >       re_run: int = 0
>
> For some reason in the doc, __init__ also appears :
> __init__(config_file_path: ~pathlib.Path = PosixPath('/ho...
>

Yes, the @dataclass decorator adds the constructor so it gets
documented. This is useful so that we see the default values.

> >
> >
> > @@ -169,7 +264,7 @@ def _get_parser() -> argparse.ArgumentParser:
> >           action=_env_arg("DTS_RERUN"),
> >           default=SETTINGS.re_run,
> >           type=int,
> > -        help="[DTS_RERUN] Re-run each test case the specified amount of times "
> > +        help="[DTS_RERUN] Re-run each test case the specified number of times "
> >           "if a test failure occurs",
> >       )
> >
> > @@ -177,6 +272,10 @@ def _get_parser() -> argparse.ArgumentParser:
> >
> >
> >   def get_settings() -> Settings:
> > +    """Create new settings with inputs from the user.
> > +
> > +    The inputs are taken from the command line and from environment variables.
> > +    """
> >       parsed_args = _get_parser().parse_args()
> >       return Settings(
> >           config_file_path=parsed_args.config_file,
>