@iwsio/json-csv-node/dist/exporter.cjs

ESM/CJS module that easily converts JSON to CSV. This package supports streaming and buffered conversion to CSV.

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.stream = exports.buffered = exports.checkOptions = void 0;
const nodeStream = require("stream");
const core = require("@iwsio/json-csv-core");
const { buffered: baseBuffered, exporter: { getHeaderRow, getBodyRow, checkOptions: baseCheckOptions } } = core;
const { Transform } = nodeStream;
/**
 * Check the options; ensure defaults. This extends core's check options with new, encoding option for streams.
 * @param opts
 * @returns
 */
const checkOptions = (opts) => {
    var _a;
    const options = baseCheckOptions(opts);
    options.encoding = (_a = opts.encoding) !== null && _a !== void 0 ? _a : 'utf8';
    return options;
};
exports.checkOptions = checkOptions;
/**
 * Same as the core's buffered function except this returns a promise for async callers rather than classic callback.
 * @param data Array of objects to be transformed.
 * @param options CSV Options
 * @returns Promise resulting in CSV output
 */
const buffered = (data, options) => {
    return new Promise((resolve, reject) => {
        try {
            const result = baseBuffered(data, options);
            resolve(result);
        }
        catch (err) {
            reject(err);
        }
    });
};
exports.buffered = buffered;
/**
 * Creates a transform stream that can be uses to pipe readable objects into for conversion to CSV.
 * @param opts CSV options
 * @returns Tranform stream that converts readable objects to csv string
 */
const stream = (opts) => {
    let writtenHeader = false;
    const options = (0, exports.checkOptions)(opts);
    const { ignoreHeader, fields, encoding } = options;
    const transformer = new Transform({
        writableObjectMode: true,
        transform(chunk, _encoding, callback) {
            // debug(`incoming chunk: ${require('util').inspect(chunk)}`)
            // debug(encoding)
            if (!writtenHeader && !ignoreHeader) {
                writtenHeader = true;
                const header = getHeaderRow(fields, options.fieldSeparator);
                // debug(`writing header ${header}`)
                this.push(header);
            }
            const row = getBodyRow(chunk, fields, options.fieldSeparator);
            // debug(`writing row ${require("util").inspect(row)}`)
            this.push(row);
            callback();
        }
    });
    transformer.setEncoding(encoding);
    return transformer;
};
exports.stream = stream;