Coverage for backend/django/core/auxiliary/formula_units.py: 75%

1from __future__ import annotations 

2 

3import re 

4 

5 

6_UNIT_TOKEN_ALIASES = { 

7 # ``min`` is a supported formula function, so bare minute units need the 

8 # unambiguous Pint spelling before the expression reaches the solver. 

9 "min": "minute", 

10} 

11_UNIT_TOKEN_PATTERN = re.compile( 

12 r"\b(" + "|".join(re.escape(token) for token in _UNIT_TOKEN_ALIASES) + r")\b" 

13) 

14 

15 

16def formula_unit_expression(unit: str) -> str | None: 

17 """Render a project unit string in the syntax accepted by formula expressions.""" 

18 

19 cleaned = unit.strip() 

20 if not cleaned: 20 ↛ 21line 20 didn't jump to line 21 because the condition on line 20 was never true

21 return "" 

22 if not all(char.isalnum() or char in {"_", "/", "*", "^", ".", " "} for char in cleaned): 22 ↛ 23line 22 didn't jump to line 23 because the condition on line 22 was never true

23 return None 

24 expression = cleaned.replace("^", "**").replace("/", " / ") 

25 return _UNIT_TOKEN_PATTERN.sub(lambda match: _UNIT_TOKEN_ALIASES[match.group(0)], expression)