stromjs/dist/functions/concat.js

Dependency-free streams utils for Node.js

"use strict";
exports.__esModule = true;
exports.concat = void 0;
var stream_1 = require("stream");
function concat() {
    var streams = [];
    for (var _i = 0; _i < arguments.length; _i++) {
        streams[_i] = arguments[_i];
    }
    var isStarted = false;
    var currentStreamIndex = 0;
    var startCurrentStream = function () {
        if (currentStreamIndex >= streams.length) {
            wrapper.push(null);
        }
        else {
            streams[currentStreamIndex]
                .on("data", function (chunk) {
                if (!wrapper.push(chunk)) {
                    streams[currentStreamIndex].pause();
                }
            })
                .on("error", function (err) { return wrapper.emit("error", err); })
                .on("end", function () {
                currentStreamIndex++;
                startCurrentStream();
            });
        }
    };
    var wrapper = new stream_1.Readable({
        objectMode: true,
        read: function () {
            if (!isStarted) {
                isStarted = true;
                startCurrentStream();
            }
            if (currentStreamIndex < streams.length) {
                streams[currentStreamIndex].resume();
            }
        }
    });
    return wrapper;
}
exports.concat = concat;