fluent-object-stream/lib/transform-factory.js

Facilitate transformation on nodeJS streams

"use strict";
var __importDefault = (this && this.__importDefault) || function (mod) {
    return (mod && mod.__esModule) ? mod : { "default": mod };
};
Object.defineProperty(exports, "__esModule", { value: true });
exports.createTransform = void 0;
const stream_1 = require("stream");
const stream_error_1 = __importDefault(require("./stream-error"));
/**
 * Utility function to create {@link Transform} stream. It handles error to propagate them.
 *
 * @param objectTransform {@link ObjectTransform} representing the transformation to apply.
 * @param options options to create the {@link Transform} stream.
 * @return the created {@link Transform} stream.
 */
function createTransform(objectTransform, options) {
    return new stream_1.Transform({
        objectMode: true,
        highWaterMark: options?.highWaterMark,
        transform: async function (value, encoding, callback) {
            try {
                await objectTransform.transformElement(value, (data) => this.push(data));
                callback();
            }
            catch (e) {
                if (e instanceof Error)
                    callback(e);
                else
                    callback(new stream_error_1.default(e));
            }
        },
        flush(callback) {
            try {
                objectTransform.onEnd?.((data) => this.push(data));
                callback();
            }
            catch (e) {
                if (e instanceof Error)
                    callback(e);
                else
                    callback(new stream_error_1.default(e));
            }
        },
    });
}
exports.createTransform = createTransform;