ivr-tester/dist/call/AudioPlaybackCaller.js

An automated testing framework for IVR call flows

"use strict";
var __importDefault = (this && this.__importDefault) || function (mod) {
    return (mod && mod.__esModule) ? mod : { "default": mod };
};
Object.defineProperty(exports, "__esModule", { value: true });
exports.AudioPlaybackCaller = void 0;
const ws_1 = __importDefault(require("ws"));
const twilio_1 = require("./twilio");
class AudioPlaybackCaller {
    constructor() {
        this.streamCounter = 0;
    }
    async call(mulawAudio, streamUrl) {
        this.streamCounter++;
        const streamSid = `audio-stream-${this.streamCounter}`;
        const ws = new ws_1.default(streamUrl);
        ws.on("open", async () => {
            ws.send(AudioPlaybackCaller.createTwilioMediaStreamStartEvent(streamSid));
            // Kludge to slowdown the rate at which data is sent to AWS
            let buffer = [];
            for (const item of mulawAudio) {
                buffer.push(item);
                if (buffer.length >= AudioPlaybackCaller.bufferSize) {
                    ws.send(AudioPlaybackCaller.createMediaEvent(streamSid, Buffer.from(buffer)));
                    buffer = [];
                    await new Promise((resolve) => setTimeout(resolve, AudioPlaybackCaller.msBetweenSendingBuffer));
                }
            }
            ws.send(AudioPlaybackCaller.createCallEndedEvent());
            ws.removeAllListeners();
            ws.close();
        });
        return Promise.resolve({
            type: "audio-playback",
            call: mulawAudio,
        });
    }
    static createTwilioMediaStreamStartEvent(sid) {
        return JSON.stringify({
            event: twilio_1.TwilioConnectionEvents.MediaStreamStart,
            streamSid: sid,
            start: {
                customParameters: {
                    from: "audio",
                    to: "playback",
                },
            },
        });
    }
    static createMediaEvent(sid, payload) {
        return JSON.stringify({
            event: twilio_1.TwilioConnectionEvents.Media,
            streamSid: sid,
            media: {
                payload: payload.toString("base64"),
            },
        });
    }
    static createCallEndedEvent() {
        return JSON.stringify({
            event: twilio_1.TwilioConnectionEvents.CallEnded,
        });
    }
}
exports.AudioPlaybackCaller = AudioPlaybackCaller;
AudioPlaybackCaller.msBetweenSendingBuffer = 250;
AudioPlaybackCaller.bufferSize = 1000;