Function checkOutputCollisions

packages/cli/src/commands/batchRender.ts:173–192

(rows: readonly PreparedBatchRow[], manifestPath: string)

}

function checkOutputCollisions(rows: readonly PreparedBatchRow[], manifestPath: string): void {
  const seen = new Map<string, number>();
  for (const row of rows) {
    const previous = seen.get(row.outputPath);
    if (previous !== undefined) {
      throw new BatchRenderInputError(
        "Batch output collision",
        `Rows ${previous} and ${row.index} both resolve to ${row.outputPath}.`,
        "Use placeholders such as {index} or a unique row key in --output.",
      );
    }
    if (row.outputPath === manifestPath) {
      throw new BatchRenderInputError(
        "Batch output collision",
        `Row ${row.index} resolves to the manifest path: ${manifestPath}.`,
      );
    }
    seen.set(row.outputPath, row.index);
  }
}

function validateBatchVariables(
  rows: readonly Record<string, unknown>[],