Fix Vale false positives on context lines in PR diffs (#181)

* Update Vale sticky comment behavior

Keep the Vale PR comment stable by updating it in place and skipping no-op updates when the rendered report is unchanged.

Co-authored-by: OpenAI GPT-5.5 <noreply@openai.com>
Co-authored-by: Cursor <cursoragent@cursor.com>

* Fix Vale false positives on context lines in PR diffs

The line-range filter was extracting hunk headers (@@ -x,y +a,b @@) and
treating the entire hunk span as "modified." Context lines within a hunk
(e.g. mapped_pages at line 3 when only a description was added at line 2)
were wrongly flagged.

Fix: walk the full patch per-file and record only actual '+' lines, one
entry per added line. Change the Python filter to exclusive upper bound
(start <= line < end) so a count=1 entry for line N matches exactly N.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

---------

Co-authored-by: OpenAI GPT-5.5 <noreply@openai.com>
Co-authored-by: Cursor <cursoragent@cursor.com>
Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: 4 people

vale/lint/action.yml

@@ -512,19 +512,25 @@ runs:
               '.[] | select(.filename == $f) | .patch // empty')
 
             if [ -n "$patch" ]; then
-              echo "$patch" | { grep '^@@' || true; } | while read -r hunk; do
-                # Extract start line and count from @@ -x,y +a,b @@
-                range=$(echo "$hunk" | sed -n 's/^@@ -[0-9,]* +\([0-9]*\),*\([0-9]*\).*/\1 \2/p')
-                start=$(echo "$range" | awk '{print $1}')
-                count=$(echo "$range" | awk '{print $2}')
-
-                # If count is empty, exactly 1 line was changed
-                if [ -z "$count" ]; then
-                  count=1
-                fi
-
-                echo "$file|$start|$count" >> "$TEMP_DIR/line_ranges.txt"
-              done
+              new_line=0
+              while IFS= read -r pline; do
+                case "$pline" in
+                  @@*)
+                    new_line=$(printf '%s\n' "$pline" | sed -n 's/^@@ -[0-9,]* +\([0-9]*\).*/\1/p')
+                    ;;
+                  +++*|---*)
+                    ;;
+                  +*)
+                    echo "$file|$new_line|1" >> "$TEMP_DIR/line_ranges.txt"
+                    new_line=$((new_line + 1))
+                    ;;
+                  -*)
+                    ;;
+                  *)
+                    new_line=$((new_line + 1))
+                    ;;
+                esac
+              done <<< "$patch"
             fi
           done < files_to_lint.txt
 

vale/lint/vale_reporter.py

@@ -155,7 +155,7 @@ def filter_issues_to_modified_lines(
             if modified_ranges:
                 if normalized_file in modified_ranges:
                     ranges = modified_ranges[normalized_file]
-                    is_modified = any(start <= line_num <= end for start, end in ranges)
+                    is_modified = any(start <= line_num < end for start, end in ranges)
                     if not is_modified:
                         stats['filtered_no_line_match'] += 1
                         if debug: