json-csv/src/string-writer.js

Easily convert JSON array to CSV in Node.JS via buffered or streaming.

const { Writable } = require('stream')
const { StringDecoder } = require('string_decoder')

// from: https://nodejs.org/docs/latest-v14.x/api/stream.html#stream_decoding_buffers_in_a_writable_stream
module.exports = class StringWritable extends Writable {
	constructor(options) {
		super(options)
		this._decoder = new StringDecoder(options && options.defaultEncoding)
		this.data = ''
	}

	_write(chunk, encoding, callback) {
		if (encoding === 'buffer') {
			chunk = this._decoder.write(chunk)
		}
		this.data += chunk
		callback()
	}

	_final(callback) {
		this.data += this._decoder.end()
		callback()
	}
}