crossbench/compat.py

# Copyright 2023 The Chromium Authors
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
""" A collection of helpers that rely on non-crossbench code."""

from __future__ import annotations

import enum
import os
import sys
import textwrap
from typing import List, NamedTuple, Optional, Tuple, Type, TypeVar, cast

import tabulate

from crossbench import path as pth

if sys.version_info >= (3, 11):
  from enum import StrEnum  # pylint: disable=unused-import
else:

  class StrEnum(str, enum.Enum):

    def __str__(self) -> str:
      return str(self.value)


if sys.version_info >= (3, 9):

  def is_relative_to(path_a: pth.AnyPath, path_b: pth.AnyPath) -> bool:
    return path_a.is_relative_to(path_b)

  def readlink(path: pth.LocalPath) -> pth.LocalPath:
    return path.readlink()
else:

  def is_relative_to(path_a: pth.AnyPath, path_b: pth.AnyPath) -> bool:
    try:
      path_a.relative_to(path_b)
      return True
    except ValueError:
      return False

  def readlink(path: pth.LocalPath) -> pth.LocalPath:
    return pth.LocalPath(os.readlink(path))


class StrHelpDataMixin(NamedTuple):
  value: str
  help: str


StrEnumWithHelpT = TypeVar("StrEnumWithHelpT", bound="StrEnumWithHelp")

class StrEnumWithHelp(StrHelpDataMixin, enum.Enum):

  @classmethod
  def _missing_(cls: Type[StrEnumWithHelpT],
                value) -> Optional[StrEnumWithHelpT]:
    value = str(value).lower()
    for member in cls:  # pytype: disable=missing-parameter
      if member.value == value:
        return member
    return None

  @classmethod
  def help_text_items(cls) -> List[Tuple[str, str]]:
    return [
        (repr(instance.value), instance.help) for instance in cls  # pytype: disable=missing-parameter
    ]

  @classmethod
  def help_text(cls, indent: int = 0) -> str:
    text: str = tabulate.tabulate(cls.help_text_items(), tablefmt="plain")
    if indent:
      return textwrap.indent(text, " " * indent)
    return text

  def __str__(self) -> str:
    return cast(str, self.value)