ipfs-web/backend/node_modules/ethers/src.ts/providers/provider-websocket.ts

import { WebSocket as _WebSocket } from "./ws.js"; /*-browser*/

import { SocketProvider } from "./provider-socket.js";

import type { JsonRpcApiProviderOptions} from "./provider-jsonrpc.js";
import type { Networkish } from "./network.js";

/**
 *  A generic interface to a Websocket-like object.
 */
export interface WebSocketLike {
    onopen: null | ((...args: Array<any>) => any);
    onmessage: null | ((...args: Array<any>) => any);
    onerror: null | ((...args: Array<any>) => any);

    readyState: number;

    send(payload: any): void;
    close(code?: number, reason?: string): void;
}

/**
 *  A function which can be used to re-create a WebSocket connection
 *  on disconnect.
 */
export type WebSocketCreator = () => WebSocketLike;

/**
 *  A JSON-RPC provider which is backed by a WebSocket.
 *
 *  WebSockets are often preferred because they retain a live connection
 *  to a server, which permits more instant access to events.
 *
 *  However, this incurs higher server infrasturture costs, so additional
 *  resources may be required to host your own WebSocket nodes and many
 *  third-party services charge additional fees for WebSocket endpoints.
 */
export class WebSocketProvider extends SocketProvider {
    #connect: null | WebSocketCreator;

    #websocket: null | WebSocketLike;
    get websocket(): WebSocketLike {
        if (this.#websocket == null) { throw new Error("websocket closed"); }
        return this.#websocket;
    }

    constructor(url: string | WebSocketLike | WebSocketCreator, network?: Networkish, options?: JsonRpcApiProviderOptions) {
        super(network, options);
        if (typeof(url) === "string") {
            this.#connect = () => { return new _WebSocket(url); };
            this.#websocket = this.#connect();
        } else if (typeof(url) === "function") {
            this.#connect = url;
            this.#websocket = url();
        } else {
            this.#connect = null;
            this.#websocket = url;
        }

        this.websocket.onopen = async () => {
            try {
                await this._start()
                this.resume();
            } catch (error) {
                console.log("failed to start WebsocketProvider", error);
                // @TODO: now what? Attempt reconnect?
            }
        };

        this.websocket.onmessage = (message: { data: string }) => {
            this._processMessage(message.data);
        };
/*
        this.websocket.onclose = (event) => {
            // @TODO: What event.code should we reconnect on?
            const reconnect = false;
            if (reconnect) {
                this.pause(true);
                if (this.#connect) {
                    this.#websocket = this.#connect();
                    this.#websocket.onopen = ...
                    // @TODO: this requires the super class to rebroadcast; move it there
                }
                this._reconnect();
            }
        };
*/
    }

    async _write(message: string): Promise<void> {
        this.websocket.send(message);
    }

    async destroy(): Promise<void> {
        if (this.#websocket != null) {
            this.#websocket.close();
            this.#websocket = null;
        }
        super.destroy();
    }
}