Coverage for src/pullapprove/trust/renames.py: 89%

1"""The file-level pure-rename rule. 

2 

3A pure rename — git found byte-identical content at a new path — produces no 

4hunks, only header metadata, so it never reaches the per-hunk rules. This rule 

5classifies the file itself, from its header lines alone. 

6 

7Default-deny like every hunk rule: the ONLY recognized shape is the exact 

8three metadata lines git emits for a same-content, same-mode rename. A rename 

9that also changes mode (`old mode`/`new mode` lines), a binary rename with 

10changes (`index` + `Binary files` lines), a copy (`copy from`/`copy to`), or 

11anything else adds or substitutes lines and is declined — those changes are 

12real and must be shown. 

13""" 

14 

15from __future__ import annotations 

16 

17from ..diff import DiffFile 

18from .labels import Trust 

19 

20 

21def trust_file_label(file: DiffFile) -> Trust | None: 

22 """Return the trust label for a hunkless file, or None when nothing matches.""" 

23 if file.hunks: 

24 return None 

25 if not file.is_move(): 

26 return None 

27 # After the `diff --git` line: exactly the pure-rename metadata, nothing 

28 # else. The paths themselves were already read from the `diff --git` line 

29 # (is_move above); prefix checks avoid re-parsing the C-quoted forms. 

30 meta = file.header_lines[1:] 

31 if len(meta) != 3: 

32 return None 

33 if meta[0] != "similarity index 100%": 

34 return None 

35 if not meta[1].startswith("rename from "): 

36 return None 

37 if not meta[2].startswith("rename to "): 

38 return None 

39 return Trust.FILE_RENAMED