handle odd hunk headers

cpp_linter/common_fs.py

@@ -2,6 +2,7 @@
 from os.path import commonpath
 from pathlib import PurePath, Path
 from typing import List, Dict, Any, Union, Tuple, Optional
+from pygit2 import DiffHunk  # type: ignore
 from .loggers import logger, start_log_group
 
 #: A path to generated cache artifacts. (only used when verbosity is in debug mode)
@@ -98,13 +99,28 @@ def serialize(self) -> Dict[str, Any]:
             },
         }
 
-    def is_in_1_hunk(self, start: int, end: int) -> bool:
+    def is_hunk_contained(self, hunk: DiffHunk) -> Optional[Tuple[int, int]]:
         """Is a given ``start`` and ``end`` line numbers within a single diff hunk?"""
+        if hunk.old_lines > 0:
+            start = hunk.old_start
+            # span of old_lines is an inclusive range
+            end = hunk.old_start + hunk.old_lines - 1
+        else:  # if number of old lines is 0
+            # start hunk at new line number
+            start = hunk.new_start
+            # make it span 1 line
+            end = start
         for hunk in self.diff_chunks:
             chunk_range = range(hunk[0], hunk[1])
             if start in chunk_range and end in chunk_range:
-                return True
-        return False
+                return (start, end)
+        logger.warning(
+            "lines %d - %d are not within a single diff hunk for file %s.",
+            start,
+            end,
+            self.name,
+        )
+        return None
 
 
 def is_file_in_list(paths: List[str], file_name: str, prompt: str) -> bool:

cpp_linter/git/git_str.py

@@ -11,7 +11,7 @@
 DIFF_FILE_NAME = re.compile(r"^\+\+\+\sb?/(.*)$", re.MULTILINE)
 DIFF_RENAMED_FILE = re.compile(r"^rename to (.*)$", re.MULTILINE)
 DIFF_BINARY_FILE = re.compile(r"^Binary\sfiles\s", re.MULTILINE)
-HUNK_INFO = re.compile(r"@@\s\-\d+,\d+\s\+(\d+,\d+)\s@@", re.MULTILINE)
+HUNK_INFO = re.compile(r"^@@\s\-\d+,?\d*\s\+(\d+,?\d*)\s@@", re.MULTILINE)
 
 
 def _get_filename_from_diff(front_matter: str) -> Optional[re.Match]:
@@ -94,7 +94,11 @@ def _parse_patch(full_patch: str) -> Tuple[List[List[int]], List[int]]:
     for index, chunk in enumerate(chunks):
         if index % 2 == 1:
             # each odd element holds the starting line number and number of lines
-            start_line, hunk_length = [int(x) for x in chunk.split(",")]
+            if "," in chunk:
+                start_line, hunk_length = [int(x) for x in chunk.split(",")]
+            else:
+                start_line = int(chunk)
+                hunk_length = 1
             ranges.append([start_line, hunk_length + start_line])
             line_numb_in_diff = start_line
             continue

cpp_linter/rest_api/github_api.py

@@ -427,18 +427,10 @@ def create_review_comments(
             full_patch += patch.text
             for hunk in patch.hunks:
                 total += 1
-                start_lines, end_lines = (
-                    hunk.old_start,
-                    hunk.old_start + hunk.old_lines,
-                )
-                if not file.is_in_1_hunk(start_lines, end_lines):
-                    logger.warning(
-                        "lines %d - %d are not within a single diff hunk for file %s.",
-                        start_lines,
-                        end_lines,
-                        file.name,
-                    )
+                new_hunk_range = file.is_hunk_contained(hunk)
+                if new_hunk_range is None:
                     continue
+                start_lines, end_lines = new_hunk_range
                 comment: Dict[str, Any] = {"path": file.name}
                 body = ""
                 if isinstance(advice, TidyAdvice):

tests/test_git_str.py

@@ -75,3 +75,30 @@ def test_ignored_diff():
     files = parse_diff_str(TYPICAL_DIFF, ["hpp"], [], [], 0)
     # binary files are ignored during parsing
     assert not files
+
+
+def test_terse_hunk_header():
+    """For coverage completeness"""
+    diff_str = "\n".join(
+        [
+            "diff --git a/src/demo.cpp b/src/demo.cpp",
+            "--- a/src/demo.cpp",
+            "+++ b/src/demo.cpp",
+            "@@ -3 +3 @@",
+            "-#include <stdio.h>",
+            "+#include <cstdio>",
+            "@@ -4,0 +5,2 @@",
+            "+auto main() -> int",
+            "+{",
+            "@@ -18 +17,2 @@ int main(){",
+            "-    return 0;}",
+            "+    return 0;",
+            "+}",
+        ]
+    )
+    files = parse_diff_str(diff_str, ["cpp"], [], [], 0)
+    assert files
+    assert files[0].diff_chunks == [[3, 4], [5, 7], [17, 19]]
+    git_files = parse_diff(diff_str, ["cpp"], [], [], 0)
+    assert git_files
+    assert files[0].diff_chunks == git_files[0].diff_chunks