refactor: tidy codes

Signed-off-by: Jack Cherng <jfcherng@gmail.com>
Signed-off-by: Jun-Fei Cherng <jfcherng@realtek.com>

plugin/utils.py

@@ -1,9 +1,50 @@
 from __future__ import annotations
 
+import io
 import os
-import re
 import subprocess
-from typing import Any
+import sys
+from collections.abc import Generator, Iterable
+from typing import Any, TypeVar
+
+_T = TypeVar("_T")
+
+
+def camel_to_snake(s: str) -> str:
+    """Converts "CamelCase" to "snake_case"."""
+    return "".join((f"_{c}" if c.isupper() else c) for c in s).strip("_").lower()
+
+
+def snake_to_camel(s: str, *, upper_first: bool = True) -> str:
+    """Converts "snake_case" to "CamelCase"."""
+    first, *others = s.split("_")
+    return (first.title() if upper_first else first.lower()) + "".join(map(str.title, others))
+
+
+if sys.version_info >= (3, 9):
+    remove_prefix = str.removeprefix
+    remove_suffix = str.removesuffix
+else:
+
+    def remove_prefix(s: str, prefix: str) -> str:
+        """Remove the prefix from the string. I.e., str.removeprefix in Python 3.9."""
+        return s[len(prefix) :] if s.startswith(prefix) else s
+
+    def remove_suffix(s: str, suffix: str) -> str:
+        """Remove the suffix from the string. I.e., str.removesuffix in Python 3.9."""
+        # suffix="" should not call s[:-0]
+        return s[: -len(suffix)] if suffix and s.endswith(suffix) else s
+
+
+def drop_falsy(iterable: Iterable[_T | None]) -> Generator[_T, None, None]:
+    """Drops falsy values from the iterable."""
+    yield from filter(None, iterable)
+
+
+def iterate_by_line(s: str) -> Generator[str, None, None]:
+    """Iterates over lines of the string."""
+    with io.StringIO(s) as f:
+        yield from f
 
 
 def get_default_startupinfo() -> Any:
@@ -14,7 +55,3 @@ def get_default_startupinfo() -> Any:
         STARTUPINFO.wShowWindow = subprocess.SW_HIDE  # type: ignore
         return STARTUPINFO
     return None
-
-
-def lowercase_drive_letter(path: str) -> str:
-    return re.sub(r"^[A-Z]+(?=:\\)", lambda m: m.group(0).lower(), path)

plugin/venv_finder.py

@@ -2,7 +2,6 @@
 
 import configparser
 import os
-import re
 import shutil
 import subprocess
 from abc import ABC, abstractmethod
@@ -16,6 +15,7 @@
 from typing_extensions import Self
 
 from .log import log_error
+from .utils import camel_to_snake, get_default_startupinfo, iterate_by_line, remove_suffix
 
 
 def find_venv_by_finder_names(finder_names: Sequence[str], *, project_dir: Path) -> VenvInfo | None:
@@ -152,32 +152,15 @@ def from_pyvenv_cfg_file(cls, pyvenv_cfg_file: str | Path) -> Self | None:
         return cls.from_venv_dir(venv_dir)
 
     @staticmethod
-    def parse_pyvenv_cfg(pyvenv_cfg: Path) -> dict[str, Any]:
+    def parse_pyvenv_cfg(pyvenv_cfg: Path) -> dict[str, str]:
         # value of these keys are expected to be a string
-        str_attr = {"command", "executable", "home", "implementation", "prompt", "uv", "version", "version_info"}
-
-        def _cast(key: str, val: str) -> Any:
-            if key in str_attr:
-                return val
-            if val.lower() == "true":
-                return True
-            if val.lower() == "false":
-                return False
-            if val.isdigit():
-                return int(val)
-            try:
-                return float(val)
-            except ValueError:
-                pass
-            return val
-
         config = configparser.ConfigParser()
         try:
             content = pyvenv_cfg.read_text(encoding="utf-8")
             config.read_string(f"[USER]\n{content}")
         except Exception:
             return {}
-        return {k: _cast(k, v) for k, v in config.items("USER")}
+        return dict(config.items("USER"))
 
 
 class BaseVenvFinder(ABC):
@@ -188,12 +171,7 @@ def __init__(self, project_dir: Path) -> None:
     @final
     @classmethod
     def name(cls) -> str:
-        name = cls.__name__
-        # remove trailing "VenvFinder"
-        if name.endswith("VenvFinder"):
-            name = name[: -len("VenvFinder")]
-        # CamelCase to snake_case
-        return "".join(f"_{c.lower()}" if c.isupper() else c for c in name).lstrip("_")
+        return camel_to_snake(remove_suffix(cls.__name__, "VenvFinder"))
 
     @final
     @classmethod
@@ -227,33 +205,25 @@ def _find_venv(self) -> VenvInfo | None:
         """Find the virtual environment. Implement this method by the subclass."""
 
     @staticmethod
-    def _find_from_venv_dir_candidates(candidates: Iterable[Path]) -> VenvInfo | None:
+    def _find_from_venv_dirs(venv_dirs: Iterable[Path]) -> VenvInfo | None:
         def _filtered_candidates() -> Generator[Path, None, None]:
-            for candidate in candidates:
+            for venv_dir in venv_dirs:
                 try:
-                    if candidate.is_dir():
-                        yield candidate
+                    if venv_dir.is_dir():
+                        yield venv_dir
                 except PermissionError:
                     pass
 
         return first_true(map(VenvInfo.from_venv_dir, _filtered_candidates()))
 
     @staticmethod
     def _run_shell_command(command: str, *, cwd: Path | None = None) -> tuple[str, str, int] | None:
-        if os.name == "nt":
-            # do not create a window for the process
-            startupinfo = subprocess.STARTUPINFO()  # type: ignore
-            startupinfo.dwFlags |= subprocess.STARTF_USESHOWWINDOW  # type: ignore
-            startupinfo.wShowWindow = subprocess.SW_HIDE  # type: ignore
-        else:
-            startupinfo = None
-
         try:
             proc = subprocess.Popen(
                 command,
                 cwd=cwd,
                 shell=True,
-                startupinfo=startupinfo,
+                startupinfo=get_default_startupinfo(),
                 stdout=subprocess.PIPE,
                 stderr=subprocess.PIPE,
                 universal_newlines=True,
@@ -277,7 +247,7 @@ def _can_support(cls, project_dir: Path) -> bool:
         return True
 
     def _find_venv(self) -> VenvInfo | None:
-        return self._find_from_venv_dir_candidates(self.project_dir.iterdir())
+        return self._find_from_venv_dirs(self.project_dir.iterdir())
 
 
 class EnvVarCondaPrefixVenvFinder(BaseVenvFinder):
@@ -289,12 +259,10 @@ class EnvVarCondaPrefixVenvFinder(BaseVenvFinder):
 
     @classmethod
     def _can_support(cls, project_dir: Path) -> bool:
-        return True
+        return "CONDA_PREFIX" in os.environ
 
     def _find_venv(self) -> VenvInfo | None:
-        if conda_prefix := os.environ.get("CONDA_PREFIX", ""):
-            return VenvInfo.from_venv_dir(conda_prefix)
-        return None
+        return VenvInfo.from_venv_dir(os.environ["CONDA_PREFIX"])
 
 
 class EnvVarVirtualEnvVenvFinder(BaseVenvFinder):
@@ -306,12 +274,10 @@ class EnvVarVirtualEnvVenvFinder(BaseVenvFinder):
 
     @classmethod
     def _can_support(cls, project_dir: Path) -> bool:
-        return True
+        return "VIRTUAL_ENV" in os.environ
 
     def _find_venv(self) -> VenvInfo | None:
-        if virtual_env := os.environ.get("VIRTUAL_ENV", ""):
-            return VenvInfo.from_venv_dir(virtual_env)
-        return None
+        return VenvInfo.from_venv_dir(os.environ["VIRTUAL_ENV"])
 
 
 class LocalDotVenvVenvFinder(BaseVenvFinder):
@@ -326,7 +292,7 @@ def _can_support(cls, project_dir: Path) -> bool:
         return True
 
     def _find_venv(self) -> VenvInfo | None:
-        return self._find_from_venv_dir_candidates((
+        return self._find_from_venv_dirs((
             self.project_dir / ".venv",
             self.project_dir / "venv",
         ))
@@ -452,7 +418,8 @@ def _find_venv(self) -> VenvInfo | None:
             return None
         stdout, _, _ = output
 
-        if m := re.search(r"^venv: (.*)$", stdout, re.MULTILINE):
-            venv_dir = m.group(1)
-            return VenvInfo.from_venv_dir(venv_dir)
+        for line in iterate_by_line(stdout):
+            pre, sep, post = line.partition(":")
+            if sep and pre == "venv":
+                return VenvInfo.from_venv_dir(post.strip())
         return None