Function processFlexibleSizeGroup

core/nextEdit/diff/diff.ts:421–439

* Process a changed area with flexible sizing.

(
  diffLines: DiffLine[],
  start: number,
  end: number,
  offset: number,
)

 * Process a changed area with flexible sizing.
 */
function processFlexibleSizeGroup(
  diffLines: DiffLine[],
  start: number,
  end: number,
  offset: number,
): DiffGroup {
  // Calculate the starting line in old content.
  let oldContentLineStart = countOldContentLines(diffLines, 0, start - 1);

  // Calculate the end line in old content.
  let oldContentLineEnd =
    oldContentLineStart + countOldContentLines(diffLines, start, end) - 1;

  return {
    startLine: oldContentLineStart + offset,
    endLine: oldContentLineEnd + offset,
    lines: diffLines.slice(start, end + 1),
  };
}