preview()

function preview(
   templateBuffer, 
   sourceBuffer, 
options?): Promise<PreviewResult>;

Defined in: impl/js/src/index.ts:380

Preview what conversion will produce without generating full files.

Returns the planned filenames, sheet names, row counts, declared inputs, and warnings the host should surface to the operator. Cheaper than convert() because it does not serialize output workbooks.

Parameters

Parameter	Type
templateBuffer	ArrayBuffer
sourceBuffer	ArrayBuffer
options?	ConvertOptions

Returns

Promise<PreviewResult>

Stable

Frozen at 1.0.

Example

const result = await preview(templateBuffer, sourceBuffer, {
  inputs: { month: '2026-05' },
});
console.log(result.files, result.warnings);