Function processLimitedSizeGroup

core/nextEdit/diff/diff.ts:365–416

* Process a changed area with a limited group size.

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

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

  // Track how many lines we have left in our group size budget.
  let remainingGroupSize = maxGroupSize;
  let currentLine = start;
  const lines: DiffLine[] = [];

  // Process lines until we hit our size limit or reach the end.
  while (currentLine <= end && remainingGroupSize > 0) {
    // Add current line to results if we haven't seen it yet.
    if (
      lines.length === 0 ||
      (lines.length > 0 &&
        lines[lines.length - 1].line !== diffLines[currentLine].line)
    ) {
      lines.push(diffLines[currentLine]);
    }

    if (diffLines[currentLine].type === "old") {
      currentLine++;
    } else if (diffLines[currentLine].type === "same") {
      remainingGroupSize--;
      currentLine++;
    } else if (diffLines[currentLine].type === "new") {
      remainingGroupSize--;
      currentLine++;
    }
  }

  // Adjust for the last increment.
  currentLine--;

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

  return {
    startLine: oldContentLineStart + offset,
    endLine: oldContentLineEnd + offset,
    lines,
  };
}

/**
 * Process a changed area with flexible sizing.