engine.io-parser/build/esm/decodePacket.browser.js

import { ERROR_PACKET, PACKET_TYPES_REVERSE, } from "./commons.js";
import { decode } from "./contrib/base64-arraybuffer.js";
const withNativeArrayBuffer = typeof ArrayBuffer === "function";
export const decodePacket = (encodedPacket, binaryType) => {
    if (typeof encodedPacket !== "string") {
        return {
            type: "message",
            data: mapBinary(encodedPacket, binaryType),
        };
    }
    const type = encodedPacket.charAt(0);
    if (type === "b") {
        return {
            type: "message",
            data: decodeBase64Packet(encodedPacket.substring(1), binaryType),
        };
    }
    const packetType = PACKET_TYPES_REVERSE[type];
    if (!packetType) {
        return ERROR_PACKET;
    }
    return encodedPacket.length > 1
        ? {
            type: PACKET_TYPES_REVERSE[type],
            data: encodedPacket.substring(1),
        }
        : {
            type: PACKET_TYPES_REVERSE[type],
        };
};
const decodeBase64Packet = (data, binaryType) => {
    if (withNativeArrayBuffer) {
        const decoded = decode(data);
        return mapBinary(decoded, binaryType);
    }
    else {
        return { base64: true, data }; // fallback for old browsers
    }
};
const mapBinary = (data, binaryType) => {
    switch (binaryType) {
        case "blob":
            if (data instanceof Blob) {
                // from WebSocket + binaryType "blob"
                return data;
            }
            else {
                // from HTTP long-polling or WebTransport
                return new Blob([data]);
            }
        case "arraybuffer":
        default:
            if (data instanceof ArrayBuffer) {
                // from HTTP long-polling (base64) or WebSocket + binaryType "arraybuffer"
                return data;
            }
            else {
                // from WebTransport (Uint8Array)
                return data.buffer;
            }
    }
};