@naturalcycles/nodejs-lib/dist/stream/ndjson/transformToNDJson.js

Standard library for Node.js

import { Transform } from 'node:stream';
import { _sortObjectDeep } from '@naturalcycles/js-lib/object';
/**
 * Transforms objects (objectMode=true) into chunks \n-terminated JSON strings (readableObjectMode=false).
 */
export function transformToNDJson(opt = {}) {
    const { strict = true, separator = '\n', sortObjects = false } = opt;
    return new Transform({
        writableObjectMode: true,
        readableObjectMode: false,
        readableHighWaterMark: 64 * 1024,
        transform(chunk, _, cb) {
            try {
                if (sortObjects) {
                    chunk = _sortObjectDeep(chunk);
                }
                cb(null, JSON.stringify(chunk) + separator);
            }
            catch (err) {
                console.error(err);
                if (strict) {
                    cb(err); // emit error
                }
                else {
                    cb(); // emit no error, but no result neither
                }
            }
        },
    });
}