Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.10/site-packages/astroid/brain/brain_hypothesis.py: 50%

1# Licensed under the LGPL: https://www.gnu.org/licenses/old-licenses/lgpl-2.1.en.html 

2# For details: https://github.com/pylint-dev/astroid/blob/main/LICENSE 

3# Copyright (c) https://github.com/pylint-dev/astroid/blob/main/CONTRIBUTORS.txt 

4 

5""" 

6Astroid hook for the Hypothesis library. 

7 

8Without this hook pylint reports no-value-for-parameter for use of strategies 

9defined using the `@hypothesis.strategies.composite` decorator. For example: 

10 

11 from hypothesis import strategies as st 

12 

13 @st.composite 

14 def a_strategy(draw): 

15 return draw(st.integers()) 

16 

17 a_strategy() 

18""" 

19from astroid.manager import AstroidManager 

20from astroid.nodes.scoped_nodes import FunctionDef 

21 

22COMPOSITE_NAMES = ( 

23 "composite", 

24 "st.composite", 

25 "strategies.composite", 

26 "hypothesis.strategies.composite", 

27) 

28 

29 

30def is_decorated_with_st_composite(node: FunctionDef) -> bool: 

31 """Return whether a decorated node has @st.composite applied.""" 

32 if node.decorators and node.args.args and node.args.args[0].name == "draw": 

33 for decorator_attribute in node.decorators.nodes: 

34 if decorator_attribute.as_string() in COMPOSITE_NAMES: 

35 return True 

36 return False 

37 

38 

39def remove_draw_parameter_from_composite_strategy(node: FunctionDef) -> FunctionDef: 

40 """Given that the FunctionDef is decorated with @st.composite, remove the 

41 first argument (`draw`) - it's always supplied by Hypothesis so we don't 

42 need to emit the no-value-for-parameter lint. 

43 """ 

44 assert isinstance(node.args.args, list) 

45 del node.args.args[0] 

46 del node.args.annotations[0] 

47 del node.args.type_comment_args[0] 

48 return node 

49 

50 

51def register(manager: AstroidManager) -> None: 

52 manager.register_transform( 

53 node_class=FunctionDef, 

54 transform=remove_draw_parameter_from_composite_strategy, 

55 predicate=is_decorated_with_st_composite, 

56 )