Function buildDuplicateSplice

packages/cli/src/batch-transform.ts:1230–1260

(
  source: string,
  nodePath: any,
  reservedKeysByParent: Map<string, Set<string>>,
)

}

function buildDuplicateSplice(
  source: string,
  nodePath: any,
  reservedKeysByParent: Map<string, Set<string>>,
): SourceSplice | null {
  const node = nodePath.node;
  const start = node.start;
  const end = node.end;
  if (start == null || end == null) return null;
  const subtreeText = source.slice(start, end);
  const processedText = deduplicateKey(subtreeText, nodePath, reservedKeysByParent);

  // Determine if this is an inline child (e.g. <a> inside <p>) or a block-level sibling.
  // Check if the element is on its own line: if the text between the previous newline
  // and the element start is only whitespace, it's block-level and gets newline+indent.
  // Otherwise it's inline and gets inserted with the same separator that follows it.
  const lineStart = source.lastIndexOf("\n", start) + 1;
  const textBeforeOnLine = source.slice(lineStart, start);
  const isBlockLevel = textBeforeOnLine.trim() === "";

  if (isBlockLevel) {
    const indent = textBeforeOnLine;
    return { offset: end, insert: "\n" + indent + processedText };
  }

  // Inline element — reuse the separator that currently follows the element
  // so duplicates preserve punctuation and spacing within prose.
  const separator = extractInlineDuplicateSeparator(source, nodePath);

  return { offset: end, insert: separator + processedText };
}

export function executeBatch(
  operations: BatchOperation[],