Coverage for src/lexigram/features/constants.py: 87%

1"""Constants for the feature-flag subsystem. 

2 

3Defines typed defaults and environment variable prefixes used across the 

4feature-flag system. Configuration models reference these to avoid 

5hard-coding values in multiple places. 

6""" 

7 

8from __future__ import annotations 

9 

10import importlib.metadata 

11 

12# -- Version ------------------------------------------------------------------- 

13 

14try: 

15 __version__: str = importlib.metadata.version("lexigram-features") 

16except ImportError: 

17 __version__ = "0.0.0" 

18 

19# -- Environment Variable Prefixes ------------------------------------------- 

20 

21ENV_PREFIX: str = "LEX_FLAG_" 

22"""Default prefix for environment variable flag definitions.""" 

23 

24ENV_NESTED_DELIMITER: str = "__" 

25"""Nested delimiter for environment variable configuration.""" 

26 

27 

28# -- Default Configuration Values -------------------------------------------- 

29 

30DEFAULT_CACHE_TTL: int = 300 

31"""Default TTL in seconds for cached flag evaluations (5 minutes).""" 

32 

33DEFAULT_ENABLED: bool = False 

34"""Default evaluation result when a flag is not found, or when a rule is 

35unconfigured (fail-closed).""" 

36 

37__all__ = [ 

38 "DEFAULT_CACHE_TTL", 

39 "DEFAULT_ENABLED", 

40 "ENV_NESTED_DELIMITER", 

41 "ENV_PREFIX", 

42]