Added BlockscoutProvider (#4790).

Author: ricmoo

src.ts/_tests/create-provider.ts

@@ -1,5 +1,6 @@
 import {
     AlchemyProvider,
+    BlockscoutProvider,
 //    AnkrProvider,
 //    CloudflareProvider,
     ChainstackProvider,
@@ -34,6 +35,15 @@ const ProviderCreators: Array<ProviderCreator> = [
             return new AlchemyProvider(network, "YrPw6SWb20vJDRFkhWq8aKnTQ8JRNRHM");
         }
     },
+    {
+        name: "BlockscoutProvider",
+        //networks: ethNetworks,  // @TODO: they are backfilling some Sepolia txs
+        networks: [ "mainnet" ],
+        create: function(network: string) {
+            //return new BlockscoutProvider(network);
+            return new BlockscoutProvider(network, "fdbfa288-1695-454e-a369-4501253a120");
+        }
+    },
     /*
     {
         name: "AnkrProvider",

src.ts/_tests/test-providers-data.ts

@@ -223,7 +223,7 @@ describe("Test Provider Transaction operations", function() {
 
             // Cloudflare doesn't return the root in legacy receipts; but it isn't
             // *actually* that important, so we'll give it a pass...
-            if (providerName === "CloudflareProvider" || providerName === "AnkrProvider" || providerName === "PocketProvider") {
+            if (providerName === "CloudflareProvider" || providerName === "AnkrProvider" || providerName === "PocketProvider" || providerName === "BlockscoutProvider") {
                 test = Object.assign({ } , test, { root: undefined });
             }
 

src.ts/ethers.ts

@@ -69,9 +69,9 @@ export {
 
     BrowserProvider,
 
-    AlchemyProvider, AnkrProvider, ChainstackProvider, CloudflareProvider,
-    EtherscanProvider, InfuraProvider, InfuraWebSocketProvider, PocketProvider,
-    QuickNodeProvider,
+    AlchemyProvider, AnkrProvider, BlockscoutProvider, ChainstackProvider,
+    CloudflareProvider, EtherscanProvider, InfuraProvider,
+    InfuraWebSocketProvider, PocketProvider, QuickNodeProvider,
 
     IpcSocketProvider, SocketProvider, WebSocketProvider,
 

src.ts/providers/default-provider.ts

@@ -3,6 +3,7 @@ import { assert } from "../utils/index.js";
 
 import { AnkrProvider } from "./provider-ankr.js";
 import { AlchemyProvider } from "./provider-alchemy.js";
+import { BlockscoutProvider } from "./provider-blockscout.js";
 import { ChainstackProvider } from "./provider-chainstack.js";
 import { CloudflareProvider } from "./provider-cloudflare.js";
 import { EtherscanProvider } from "./provider-etherscan.js";
@@ -121,6 +122,12 @@ export function getDefaultProvider(network?: string | Networkish | WebSocketLike
         } catch (error) { }
     }
 
+    if (allowService("blockscout")) {
+        try {
+            providers.push(new BlockscoutProvider(network, options.blockscout));
+        } catch (error) { }
+    }
+
     if (allowService("chainstack")) {
         try {
             providers.push(new ChainstackProvider(network, options.chainstack));

src.ts/providers/index.ts

@@ -60,6 +60,7 @@ export { JsonRpcApiProvider, JsonRpcProvider, JsonRpcSigner } from "./provider-j
 export { BrowserProvider } from "./provider-browser.js";
 
 export { AlchemyProvider } from "./provider-alchemy.js";
+export { BlockscoutProvider } from "./provider-blockscout.js";
 export { AnkrProvider } from "./provider-ankr.js";
 export { CloudflareProvider } from "./provider-cloudflare.js";
 export { ChainstackProvider } from "./provider-chainstack.js";

src.ts/providers/provider-blockscout.ts

@@ -0,0 +1,119 @@
+
+/**
+ *  [[link-blockscout]] provides a third-party service for connecting to
+ *  various blockchains over JSON-RPC.
+ *
+ *  **Supported Networks**
+ *
+ *  - Ethereum Mainnet (``mainnet``)
+ *  - Sepolia Testnet (``sepolia``)
+ *  - Ethereum Classic (``classic``)
+ *  - Arbitrum (``arbitrum``)
+ *  - Base (``base``)
+ *  - Base Sepolia Testnet (``base-sepolia``)
+ *  - Gnosis (``xdai``)
+ *  - Optimism (``optimism``)
+ *  - Optimism Sepolia Testnet (``optimism-sepolia``)
+ *  - Polygon (``matic``)
+ *
+ *  @_subsection: api/providers/thirdparty:Blockscout  [providers-blockscout]
+ */
+import {
+    defineProperties, FetchRequest, assertArgument
+} from "../utils/index.js";
+
+import { Network } from "./network.js";
+import { JsonRpcProvider } from "./provider-jsonrpc.js";
+
+import type { AbstractProvider } from "./abstract-provider.js";
+import type { CommunityResourcable } from "./community.js";
+import type { Networkish } from "./network.js";
+
+
+function getUrl(name: string): string {
+    switch(name) {
+        case "mainnet":
+            return "https:/\/eth.blockscout.com/api/eth-rpc";
+        case "sepolia":
+            return "https:/\/eth-sepolia.blockscout.com/api/eth-rpc";
+        case "holesky":
+            return "https:/\/eth-holesky.blockscout.com/api/eth-rpc";
+
+        case "classic":
+            return "https:/\/etc.blockscout.com/api/eth-rpc";
+
+        case "arbitrum":
+            return "https:/\/arbitrum.blockscout.com/api/eth-rpc";
+
+        case "base":
+            return "https:/\/base.blockscout.com/api/eth-rpc";
+        case "base-sepolia":
+            return "https:/\/base-sepolia.blockscout.com/api/eth-rpc";
+
+        case "matic":
+            return "https:/\/polygon.blockscout.com/api/eth-rpc";
+
+        case "optimism":
+            return "https:/\/optimism.blockscout.com/api/eth-rpc";
+        case "optimism-sepolia":
+            return "https:/\/optimism-sepolia.blockscout.com/api/eth-rpc";
+
+        case "xdai":
+            return "https:/\/gnosis.blockscout.com/api/eth-rpc";
+    }
+
+    assertArgument(false, "unsupported network", "network", name);
+}
+
+
+/**
+ *  The **BlockscoutProvider** connects to the [[link-blockscout]]
+ *  JSON-RPC end-points.
+ *
+ *  By default, a highly-throttled API key is used, which is
+ *  appropriate for quick prototypes and simple scripts. To
+ *  gain access to an increased rate-limit, it is highly
+ *  recommended to [sign up here](link-blockscout).
+ */
+export class BlockscoutProvider extends JsonRpcProvider implements CommunityResourcable {
+    /**
+     *  The API key.
+     */
+    readonly apiKey!: null | string;
+
+    /**
+     *  Creates a new **BlockscoutProvider**.
+     */
+    constructor(_network?: Networkish, apiKey?: null | string) {
+        if (_network == null) { _network = "mainnet"; }
+        const network = Network.from(_network);
+
+        if (apiKey == null) { apiKey = null; }
+
+        const request = BlockscoutProvider.getRequest(network);
+        super(request, network, { staticNetwork: network });
+
+        defineProperties<BlockscoutProvider>(this, { apiKey });
+    }
+
+    _getProvider(chainId: number): AbstractProvider {
+        try {
+            return new BlockscoutProvider(chainId, this.apiKey);
+        } catch (error) { }
+        return super._getProvider(chainId);
+    }
+
+    isCommunityResource(): boolean {
+        return (this.apiKey === null);
+    }
+
+    /**
+     *  Returns a prepared request for connecting to %%network%%
+     *  with %%apiKey%%.
+     */
+    static getRequest(network: Network): FetchRequest {
+        const request = new FetchRequest(getUrl(network.name));
+        request.allowGzip = true;
+        return request;
+    }
+}