ethers.js/src.ts/providers/default-provider.ts

import { assert } from "../utils/index.js";

import { AnkrProvider } from "./provider-ankr.js";
import { AlchemyProvider } from "./provider-alchemy.js";
import { CloudflareProvider } from "./provider-cloudflare.js";
import { EtherscanProvider } from "./provider-etherscan.js";
import { InfuraProvider } from "./provider-infura.js";
//import { PocketProvider } from "./provider-pocket.js";
import { QuickNodeProvider } from "./provider-quicknode.js";

import { FallbackProvider } from "./provider-fallback.js";
import { JsonRpcProvider } from "./provider-jsonrpc.js";
import { WebSocketProvider } from "./provider-websocket.js";

import type { AbstractProvider } from "./abstract-provider.js";
import type { Networkish } from "./network.js";
import { WebSocketLike } from "./provider-websocket.js";

function isWebSocketLike(value: any): value is WebSocketLike {
    return (value && typeof(value.send) === "function" &&
        typeof(value.close) === "function");
}

export function getDefaultProvider(network: string | Networkish | WebSocketLike, options?: any): AbstractProvider {
    if (options == null) { options = { }; }

    if (typeof(network) === "string" && network.match(/^https?:/)) {
        return new JsonRpcProvider(network);
    }

    if (typeof(network) === "string" && network.match(/^wss?:/) || isWebSocketLike(network)) {
        return new WebSocketProvider(network);
    }

    const providers: Array<AbstractProvider> = [ ];

    if (options.alchemy !== "-") {
        try {
            providers.push(new AlchemyProvider(network, options.alchemy));
        } catch (error) { console.log(error); }
    }

    if (options.ankr !== "-") {
        try {
            providers.push(new AnkrProvider(network, options.ankr));
        } catch (error) { console.log(error); }
    }

    if (options.cloudflare !== "-") {
        try {
            providers.push(new CloudflareProvider(network));
        } catch (error) { console.log(error); }
    }

    if (options.etherscan !== "-") {
        try {
            providers.push(new EtherscanProvider(network, options.etherscan));
        } catch (error) { console.log(error); }
    }

    if (options.infura !== "-") {
        try {
            let projectId = options.infura;
            let projectSecret: undefined | string = undefined;
            if (typeof(projectId) === "object") {
                projectSecret = projectId.projectSecret;
                projectId = projectId.projectId;
            }
            providers.push(new InfuraProvider(network, projectId, projectSecret));
        } catch (error) { console.log(error); }
    }
/*
    if (options.pocket !== "-") {
        try {
            let appId = options.pocket;
            let secretKey: undefined | string = undefined;
            let loadBalancer: undefined | boolean = undefined;
            if (typeof(appId) === "object") {
                loadBalancer = !!appId.loadBalancer;
                secretKey = appId.secretKey;
                appId = appId.appId;
            }
            providers.push(new PocketProvider(network, appId, secretKey, loadBalancer));
        } catch (error) { console.log(error); }
    }
*/
    if (options.quicknode !== "-") {
        try {
            let token = options.qquicknode;
            providers.push(new QuickNodeProvider(network, token));
        } catch (error) { console.log(error); }
    }

    assert(providers.length, "unsupported default network", "UNSUPPORTED_OPERATION", {
        operation: "getDefaultProvider"
    });

    if (providers.length === 1) { return providers[0]; }

    return new FallbackProvider(providers);
}