Re: [PATCH v1] dts: strip whitespaces from stdout and stderr

[Jeremy Spewock <jspewock@iol.unh.edu>]

On Wed, Feb 7, 2024 at 7:16 AM Juraj Linkeš <juraj.linkes@pantheon.tech> wrote:
>
> There could be a newline at the end of stdout or stderr of a remotely
> executed command. These cause issues when used later, such as when
> joining paths from such commands - a newline in the middle of a path is
> not valid.
>
> Fixes: ad80f550dbc5 ("dts: add SSH command verification")
> Signed-off-by: Juraj Linkeš <juraj.linkes@pantheon.tech>
> ---
>  .../remote_session/remote_session.py          | 24 +++++++++++++++----
>  1 file changed, 20 insertions(+), 4 deletions(-)
>
> diff --git a/dts/framework/remote_session/remote_session.py b/dts/framework/remote_session/remote_session.py
> index 2059f9a981..6bea1a2306 100644
> --- a/dts/framework/remote_session/remote_session.py
> +++ b/dts/framework/remote_session/remote_session.py
> @@ -10,8 +10,8 @@
>  """
>
>
> -import dataclasses
>  from abc import ABC, abstractmethod
> +from dataclasses import InitVar, dataclass, field
>  from pathlib import PurePath
>
>  from framework.config import NodeConfiguration
> @@ -20,7 +20,7 @@
>  from framework.settings import SETTINGS
>
>
> -@dataclasses.dataclass(slots=True, frozen=True)
> +@dataclass(slots=True, frozen=True)
>  class CommandResult:
>      """The result of remote execution of a command.
>
> @@ -34,9 +34,25 @@ class CommandResult:
>
>      name: str
>      command: str
> -    stdout: str
> -    stderr: str
> +    init_stdout: InitVar[str]
> +    init_stderr: InitVar[str]
>      return_code: int
> +    stdout: str = field(init=False)
> +    stderr: str = field(init=False)
> +
> +    def __post_init__(self, init_stdout, init_stderr):

Are the typehints skipped deliberately here because it's redundant? We
might want to include them anyway just for better typehint coverage.

> +        """Strip the whitespaces from stdout and stderr.
> +
> +        The generated __init__ method uses object.__setattr__() when the dataclass is frozen,
> +        so that's what we use here as well.
> +
> +        In order to get access to dataclass fields in the __post_init__ method,
> +        we have to type them as InitVars. These InitVars are included in the __init__ method's
> +        signature, so we have to exclude the actual stdout and stderr fields
> +        from the __init__ method's signature, so that we have the proper number of arguments.
> +        """
> +        object.__setattr__(self, "stdout", init_stdout.strip())
> +        object.__setattr__(self, "stderr", init_stderr.strip())
>
>      def __str__(self) -> str:
>          """Format the command outputs."""
> --
> 2.34.1
>