Added basic Gas Station support via a NetworkPlugin (#2828).

src.ts/providers/abstract-provider.ts

@@ -44,6 +44,7 @@ import type { BigNumberish, BytesLike } from "../utils/index.js";
 import type { Listener } from "../utils/index.js";
 
 import type { Networkish } from "./network.js";
+import type { FetchUrlFeeDataNetworkPlugin } from "./plugins-network.js";
 //import type { MaxPriorityFeePlugin } from "./plugins-network.js";
 import type {
     BlockParams, LogParams, TransactionReceiptParams,
@@ -410,10 +411,12 @@ type _PerformAccountRequest = {
  */
 export type AbstractProviderOptions = {
     cacheTimeout?: number;
+    pollingInterval?: number;
 };
 
 const defaultOptions = {
-    cacheTimeout: 250
+    cacheTimeout: 250,
+    pollingInterval: 4000
 };
 
 type CcipArgs = {
@@ -493,6 +496,8 @@ export class AbstractProvider implements Provider {
         this.#disableCcipRead = false;
     }
 
+    get pollingInterval(): number { return this.#options.pollingInterval; }
+
     /**
      *  Returns ``this``, to allow an **AbstractProvider** to implement
      *  the [[ContractRunner]] interface.
@@ -888,8 +893,11 @@ export class AbstractProvider implements Provider {
     }
 
     async getFeeData(): Promise<FeeData> {
-        const { block, gasPrice } = await resolveProperties({
+        const network = await this.getNetwork();
-            block: this.getBlock("latest"),
+
+        const getFeeDataFunc = async () => {
+            const { _block, gasPrice } = await resolveProperties({
+                _block: this.#getBlock("latest", false),
                 gasPrice: ((async () => {
                     try {
                         const gasPrice = await this.#perform({ method: "getGasPrice" });
@@ -901,21 +909,25 @@ export class AbstractProvider implements Provider {
 
             let maxFeePerGas = null, maxPriorityFeePerGas = null;
 
+            // These are the recommended EIP-1559 heuristics for fee data
+            const block = this._wrapBlock(_block, network);
             if (block && block.baseFeePerGas) {
-            // We may want to compute this more accurately in the future,
-            // using the formula "check if the base fee is correct".
-            // See: https://eips.ethereum.org/EIPS/eip-1559
                 maxPriorityFeePerGas = BigInt("1000000000");
-
-            // Allow a network to override their maximum priority fee per gas
-            //const priorityFeePlugin = (await this.getNetwork()).getPlugin<MaxPriorityFeePlugin>("org.ethers.plugins.max-priority-fee");
-            //if (priorityFeePlugin) {
-            //    maxPriorityFeePerGas = await priorityFeePlugin.getPriorityFee(this);
-            //}
                 maxFeePerGas = (block.baseFeePerGas * BN_2) + maxPriorityFeePerGas;
             }
 
             return new FeeData(gasPrice, maxFeePerGas, maxPriorityFeePerGas);
+        };
+
+        // Check for a FeeDataNetWorkPlugin
+        const plugin = <FetchUrlFeeDataNetworkPlugin>network.getPlugin("org.ethers.plugins.network.FetchUrlFeeDataPlugin");
+        if (plugin) {
+            const req = new FetchRequest(plugin.url);
+            const feeData = await plugin.processFunc(getFeeDataFunc, this, req);
+            return new FeeData(feeData.gasPrice, feeData.maxFeePerGas, feeData.maxPriorityFeePerGas);
+        }
+
+        return await getFeeDataFunc();
     }
 
 
@@ -1301,8 +1313,11 @@ export class AbstractProvider implements Provider {
             case "error":
             case "network":
                 return new UnmanagedSubscriber(sub.type);
-            case "block":
+            case "block": {
-                return new PollingBlockSubscriber(this);
+                const subscriber = new PollingBlockSubscriber(this);
+                subscriber.pollingInterval = this.pollingInterval;
+                return subscriber;
+            }
             case "event":
                 return new PollingEventSubscriber(this, sub.filter);
             case "transaction":

src.ts/providers/network.ts

@@ -6,10 +6,11 @@
  */
 
 import { accessListify } from "../transaction/index.js";
-import { getBigInt, assertArgument } from "../utils/index.js";
+import { getBigInt, assert, assertArgument } from "../utils/index.js";
 
-import { EnsPlugin, GasCostPlugin } from "./plugins-network.js";
+import {
-//import { EtherscanPlugin } from "./provider-etherscan-base.js";
+    EnsPlugin, FetchUrlFeeDataNetworkPlugin, GasCostPlugin
+} from "./plugins-network.js";
 
 import type { BigNumberish } from "../utils/index.js";
 import type { TransactionLike } from "../transaction/index.js";
@@ -53,44 +54,9 @@ export class LayerOneConnectionPlugin extends NetworkPlugin {
 }
 */
 
-/* * * *
-export class PriceOraclePlugin extends NetworkPlugin {
-    readonly address!: string;
-
-    constructor(address: string) {
-        super("org.ethers.plugins.price-oracle");
-        defineProperties<PriceOraclePlugin>(this, { address });
-    }
-
-    clone(): PriceOraclePlugin {
-        return new PriceOraclePlugin(this.address);
-    }
-}
-*/
-
-// Networks or clients with a higher need for security (such as clients
-// that may automatically make CCIP requests without user interaction)
-// can use this plugin to anonymize requests or intercept CCIP requests
-// to notify and/or receive authorization from the user
-/* * * *
-export type FetchDataFunc = (req: Frozen<FetchRequest>) => Promise<FetchRequest>;
-export class CcipPreflightPlugin extends NetworkPlugin {
-    readonly fetchData!: FetchDataFunc;
-
-    constructor(fetchData: FetchDataFunc) {
-        super("org.ethers.plugins.ccip-preflight");
-        defineProperties<CcipPreflightPlugin>(this, { fetchData });
-    }
-
-    clone(): CcipPreflightPlugin {
-        return new CcipPreflightPlugin(this.fetchData);
-    }
-}
-*/
 
 const Networks: Map<string | bigint, () => Network> = new Map();
 
-// @TODO: Add a _ethersNetworkObj variable to better detect network ovjects
 
 /**
  *  A **Network** provides access to a chain's properties and allows
@@ -318,11 +284,61 @@ export class Network {
 
 type Options = {
     ensNetwork?: number;
-    priorityFee?: number
     altNames?: Array<string>;
-    etherscan?: { url: string };
+    plugins?: Array<NetworkPlugin>;
 };
 
+// We don't want to bring in formatUnits because it is backed by
+// FixedNumber and we want to keep Networks tiny. The values
+// included by the Gas Stations are also IEEE 754 with lots of
+// rounding issues and exceed the strict checks formatUnits has.
+function parseUnits(_value: number | string, decimals: number): bigint {
+    const value = String(_value);
+    if (!value.match(/^[0-9.]+$/)) {
+        throw new Error(`invalid gwei value: ${ _value }`);
+    }
+
+    // Break into [ whole, fraction ]
+    const comps = value.split(".");
+    if (comps.length === 1) { comps.push(""); }
+
+    // More than 1 decimal point or too many fractional positions
+    if (comps.length !== 2) {
+        throw new Error(`invalid gwei value: ${ _value }`);
+    }
+
+    // Pad the fraction to 9 decimalplaces
+    while (comps[1].length < decimals) { comps[1] += "0"; }
+
+    // Too many decimals and some non-zero ending, take the ceiling
+    if (comps[1].length > 9 && !comps[1].substring(9).match(/^0+$/)) {
+        comps[1] = (BigInt(comps[1].substring(0, 9)) + BigInt(1)).toString();
+    }
+
+    return BigInt(comps[0] + comps[1]);
+}
+
+function getGasStationPlugin(url: string) {
+    return new FetchUrlFeeDataNetworkPlugin(url, async (fetchFeeData, provider, request) => {
+
+        // Prevent Cloudflare from blocking our request in node.js
+        request.setHeader("User-Agent", "ethers");
+
+        let response;
+        try {
+            response = await request.send();
+            const payload = response.bodyJson.standard;
+            const feeData = {
+                maxFeePerGas: parseUnits(payload.maxFee, 9),
+                maxPriorityFeePerGas: parseUnits(payload.maxPriorityFee, 9),
+            };
+            return feeData;
+        } catch (error) {
+            assert(false, `error encountered with polygon gas station (${ JSON.stringify(request.url) })`, "SERVER_ERROR", { request, response, info: { error } });
+        }
+    });
+}
+
 // See: https://chainlist.org
 let injected = false;
 function injectCommonNetworks(): void {
@@ -339,17 +355,12 @@ function injectCommonNetworks(): void {
                 network.attachPlugin(new EnsPlugin(null, options.ensNetwork));
             }
 
-            if (options.priorityFee) {
-//                network.attachPlugin(new MaxPriorityFeePlugin(options.priorityFee));
-            }
-/*
-            if (options.etherscan) {
-                const { url, apiKey } = options.etherscan;
-                network.attachPlugin(new EtherscanPlugin(url, apiKey));
-            }
-*/
             network.attachPlugin(new GasCostPlugin());
 
+            (options.plugins || []).forEach((plugin) => {
+                network.attachPlugin(plugin);
+            });
+
             return network;
         };
 
@@ -378,49 +389,28 @@ function injectCommonNetworks(): void {
 
     registerEth("optimism", 10, {
         ensNetwork: 1,
-        etherscan: { url: "https:/\/api-optimistic.etherscan.io/" }
-    });
-    registerEth("optimism-goerli", 420, {
-        etherscan: { url: "https:/\/api-goerli-optimistic.etherscan.io/" }
     });
+    registerEth("optimism-goerli", 420, { });
 
     registerEth("arbitrum", 42161, {
         ensNetwork: 1,
-        etherscan: { url: "https:/\/api.arbiscan.io/" }
-    });
-    registerEth("arbitrum-goerli", 421613, {
-        etherscan: { url: "https:/\/api-goerli.arbiscan.io/" }
     });
+    registerEth("arbitrum-goerli", 421613, { });
 
     // Polygon has a 35 gwei maxPriorityFee requirement
     registerEth("matic", 137, {
         ensNetwork: 1,
-//        priorityFee: 35000000000,
+        plugins: [
-        etherscan: {
+            getGasStationPlugin("https:/\/gasstation.polygon.technology/v2")
-//            apiKey: "W6T8DJW654GNTQ34EFEYYP3EZD9DD27CT7",
+        ]
-            url: "https:/\/api.polygonscan.com/"
-        }
     });
     registerEth("matic-mumbai", 80001, {
         altNames: [ "maticMumbai", "maticmum" ],  // @TODO: Future remove these alts
-//        priorityFee: 35000000000,
+        plugins: [
-        etherscan: {
+            getGasStationPlugin("https:/\/gasstation-testnet.polygon.technology/v2")
-//            apiKey: "W6T8DJW654GNTQ34EFEYYP3EZD9DD27CT7",
+        ]
-            url: "https:/\/api-testnet.polygonscan.com/"
-        }
     });
 
-    registerEth("bnb", 56, {
+    registerEth("bnb", 56, { ensNetwork: 1 });
-        ensNetwork: 1,
+    registerEth("bnbt", 97, { });
-        etherscan: {
-//            apiKey: "EVTS3CU31AATZV72YQ55TPGXGMVIFUQ9M9",
-            url: "http:/\/api.bscscan.com"
-        }
-    });
-    registerEth("bnbt", 97, {
-        etherscan: {
-//            apiKey: "EVTS3CU31AATZV72YQ55TPGXGMVIFUQ9M9",
-            url: "http:/\/api-testnet.bscscan.com"
-        }
-    });
 }

src.ts/providers/plugins-network.ts

@@ -2,10 +2,8 @@ import { defineProperties } from "../utils/properties.js";
 
 import { assertArgument } from "../utils/index.js";
 
-import type {
+import type { FeeData, Provider } from "./provider.js";
-    FeeData, Provider
+import type { FetchRequest } from "../utils/fetch.js";
-} from "./provider.js";
-
 
 
 const EnsAddress = "0x00000000000C2E074eC69A0dFb2997BA6C7d2e1e";
@@ -229,6 +227,23 @@ export class FeeDataNetworkPlugin extends NetworkPlugin {
     }
 }
 
+export class FetchUrlFeeDataNetworkPlugin extends NetworkPlugin {
+    readonly #url: string;
+    readonly #processFunc: (f: () => Promise<FeeData>, p: Provider, r: FetchRequest) => Promise<{ gasPrice?: null | bigint, maxFeePerGas?: null | bigint, maxPriorityFeePerGas?: null | bigint }>;
+
+    get url() { return this.#url; }
+    get processFunc() { return this.#processFunc; }
+
+    constructor(url: string, processFunc: (f: () => Promise<FeeData>, p: Provider, r: FetchRequest) => Promise<{ gasPrice?: null | bigint, maxFeePerGas?: null | bigint, maxPriorityFeePerGas?: null | bigint }>) {
+        super("org.ethers.plugins.network.FetchUrlFeeDataPlugin");
+        this.#url = url;
+        this.#processFunc = processFunc;
+    }
+
+    // We are immutable, so we can serve as our own clone
+    clone(): FetchUrlFeeDataNetworkPlugin { return this; }
+}
+
 /*
 export class CustomBlockNetworkPlugin extends NetworkPlugin {
     readonly #blockFunc: (provider: Provider, block: BlockParams<string>) => Block<string>;