@naturalcycles/nodejs-lib/dist/csv/transformToCSV.js

Standard library for Node.js

import { Transform } from 'node:stream';
import { CSVWriter } from './csvWriter.js';
/**
 * Transforms objects (objectMode=true) into chunks \n-terminated CSV strings (readableObjectMode=false).
 */
export function transformToCSV(opt) {
    const { strict = true } = opt;
    const writer = new CSVWriter(opt);
    let firstRow = true;
    return new Transform({
        writableObjectMode: true,
        readableObjectMode: false,
        readableHighWaterMark: 64 * 1024,
        transform(chunk, _, cb) {
            try {
                let s = '';
                if (firstRow) {
                    s = writer.writeHeader() + '\n';
                    firstRow = false;
                }
                cb(null, s + writer.writeRow(chunk) + '\n');
            }
            catch (err) {
                console.error(err);
                if (strict) {
                    cb(err); // emit error
                }
                else {
                    cb(); // emit no error, but no result neither
                }
            }
        },
    });
}