anchor.diff:  
     // - - - - - - - - - - - - - - - - - - - - - - - -
   
  -  const makeDiffDeletedCount = (diff) => {
  -    return makeDiffCount(diff, 'deleted_line_count', 'deleted');
  -  };
  -
  -  const makeDiffAddedCount = (diff) => {
  -    return makeDiffCount(diff, 'added_line_count', 'added');
  -  };
  -
  -  const makeDiffCount = (diff, propertyName, cssName) => {
  +  const makeDiffDeletedCount = (showCounts, diff) => {
  +    return makeDiffCount(showCounts, diff, 'deleted_line_count', 'deleted');
  +  };
  +
  +  const makeDiffAddedCount = (showCounts, diff) => {
  +    return makeDiffCount(showCounts, diff, 'added_line_count', 'added');
  +  };
  +
  +  const makeDiffCount = (showCounts, diff, propertyName, cssName) => {
       if (!inDiffMode()) {
         return '';
       }
  
positive.code:       'class': `diff-${cssName}-line-count button`,
        'data-filename': diff.filename
      });
      const count = diff[propertyName];
      if (count !== 0) {
        div.append(count);
      }
      return outerHTML(div);
    };
  
negative.code:     let html = '';
      $.each(sortedDiffs(diffs), (_, diff) => {
        html += '<div class="diff-filename-box">';
        const deletedLineCount = diff['delete_line_count'];
        const addedLineCount = diff['added_line_count'];
        const showCounts = (deletedLineCount > 0 || addedLineCount > 0);
        html += makeDiffDeletedCount(showCounts, diff);
        html += makeDiffAddedCount(showCounts, diff);
        html += makeDiffFilename(diff);
        html += '</div>';
      });
  