Function myersDiff

core/diff/myers.ts:29–57

(oldContent: string, newContent: string)

// [ { type: "old", line: "foo" }, { type: "new", line: "foo" } ], we
// pass ignoreNewlineAtEof: true.
export function myersDiff(oldContent: string, newContent: string): DiffLine[] {
  const theirFormat = diffLines(oldContent, newContent, {
    ignoreNewlineAtEof: true,
  });
  let ourFormat = theirFormat.flatMap(convertMyersChangeToDiffLines);

  // Combine consecutive old/new pairs that are identical after trimming
  for (let i = 0; i < ourFormat.length - 1; i++) {
    if (
      ourFormat[i]?.type === "old" &&
      ourFormat[i + 1]?.type === "new" &&
      ourFormat[i].line.trim() === ourFormat[i + 1].line.trim()
    ) {
      ourFormat[i] = { type: "same", line: ourFormat[i].line };
      ourFormat.splice(i + 1, 1);
    }
  }

  // Remove trailing empty old lines
  while (
    ourFormat.length > 0 &&
    ourFormat[ourFormat.length - 1].type === "old" &&
    ourFormat[ourFormat.length - 1].line === ""
  ) {
    ourFormat.pop();
  }

  return ourFormat;
}

export function myersCharDiff(
  oldContent: string,