Coverage for lintro / tools / core / install_strategies / environment.py: 60%

1"""Install environment detection for strategy-based tool installation. 

2 

3Provides a slim, frozen data object describing what package managers are 

4available on the current system. Strategy classes receive this instead of 

5the full ``RuntimeContext`` so they stay decoupled from CI detection, 

6platform labels, and other unrelated concerns. 

7""" 

8 

9from __future__ import annotations 

10 

11import shutil 

12from dataclasses import dataclass 

13 

14from lintro.enums.install_context import InstallContext, PackageManager 

15 

16 

17@dataclass(frozen=True) 

18class InstallEnvironment: 

19 """Available package managers and install context. 

20 

21 Attributes: 

22 install_context: How lintro was installed. 

23 available_managers: Set of package manager identifiers found on PATH. 

24 """ 

25 

26 install_context: InstallContext 

27 available_managers: frozenset[PackageManager] 

28 

29 def has(self, manager: PackageManager) -> bool: 

30 """Check if a package manager is available. 

31 

32 Args: 

33 manager: Package manager to check. 

34 

35 Returns: 

36 True if the manager was found on PATH. 

37 """ 

38 return manager in self.available_managers 

39 

40 @classmethod 

41 def detect(cls, install_context: InstallContext) -> InstallEnvironment: 

42 """Detect available package managers from PATH. 

43 

44 Args: 

45 install_context: How lintro was installed (passed in from 

46 the existing ``_detect_install_context`` helper). 

47 

48 Returns: 

49 InstallEnvironment with detected values. 

50 """ 

51 managers: set[PackageManager] = set() 

52 for pm in PackageManager: 

53 if pm == PackageManager.PIP: 

54 # Accept pip3 as pip fallback 

55 if shutil.which("pip") is not None or shutil.which("pip3") is not None: 

56 managers.add(pm) 

57 elif shutil.which(pm) is not None: 

58 managers.add(pm) 

59 return cls( 

60 install_context=install_context, 

61 available_managers=frozenset(managers), 

62 )