Coverage for src / rtflite / type_guards.py: 87%

1"""Type guards for RTF components to handle Union types safely.""" 

2 

3from collections.abc import Sequence 

4from typing import Any, TypeGuard 

5 

6from .input import RTFBody, RTFColumnHeader 

7 

8 

9def is_single_header( 

10 header: RTFColumnHeader | Sequence[RTFColumnHeader | None] | None, 

11) -> TypeGuard[RTFColumnHeader]: 

12 """Check if header is a single RTFColumnHeader instance.""" 

13 return header is not None and not isinstance(header, (list, tuple)) 

14 

15 

16def is_single_body(body: RTFBody | list[RTFBody] | None) -> TypeGuard[RTFBody]: 

17 """Check if body is a single RTFBody instance.""" 

18 return isinstance(body, RTFBody) 

19 

20 

21def is_list_header( 

22 header: RTFColumnHeader | Sequence[RTFColumnHeader | None] | None, 

23) -> TypeGuard[Sequence[RTFColumnHeader | None]]: 

24 """Check if header is a sequence of RTFColumnHeader instances.""" 

25 return isinstance(header, (list, tuple)) 

26 

27 

28def is_list_body(body: RTFBody | list[RTFBody] | None) -> TypeGuard[list[RTFBody]]: 

29 """Check if body is a list of RTFBody instances.""" 

30 return isinstance(body, list) 

31 

32 

33def is_nested_header_list( 

34 header: Any, 

35) -> TypeGuard[list[list[RTFColumnHeader | None]]]: 

36 """Check if header is a nested list of RTFColumnHeader instances.""" 

37 return isinstance(header, list) and len(header) > 0 and isinstance(header[0], list) 

38 

39 

40def is_flat_header_list( 

41 header: Any, 

42) -> TypeGuard[list[RTFColumnHeader | None]]: 

43 """Check if header is a flat list of RTFColumnHeader instances.""" 

44 return isinstance(header, list) and ( 

45 len(header) == 0 or not isinstance(header[0], list) 

46 )