Add empty string URL validation in HttpProvider

Author: kshyun28

packages/hardhat-core/src/internal/core/errors-list.ts

@@ -475,6 +475,17 @@ Please double check your transactions' parameters.`,
 Please check that you are sending an \`address\` parameter.`,
       shouldBeReported: false,
     },
+    EMPTY_URL: {
+      number: 117,
+      message:
+        "Empty string `%value%` for network or forking URL - Expected a non-empty string.",
+      title:
+        "Empty string `%value%` for network or forking URL - Expected a non-empty string.",
+      description: `You are trying to connect to a network with an empty network or forking URL.
+
+Please check that you are sending a non-empty string for network or forking \`URL\` parameter.`,
+      shouldBeReported: false,
+    },
   },
   TASK_DEFINITIONS: {
     PARAM_AFTER_VARIADIC: {

packages/hardhat-core/src/internal/core/providers/http.ts

@@ -51,6 +51,12 @@ export class HttpProvider extends EventEmitter implements EIP1193Provider {
 
     const { Pool, ProxyAgent } = require("undici") as typeof Undici;
 
+    if (this._url.trim().length === 0) {
+      throw new HardhatError(ERRORS.NETWORK.EMPTY_URL, {
+        value: this._url,
+      });
+    }
+
     const url = new URL(this._url);
     this._path = url.pathname;
     this._authHeader =

packages/hardhat-core/test/internal/core/providers/http.ts

@@ -2,7 +2,9 @@ import { assert } from "chai";
 import { MockAgent, MockPool } from "undici";
 
 import { HttpProvider } from "../../../../src/internal/core/providers/http";
+import { ERRORS } from "../../../../src/internal/core/errors-list";
 import { SuccessfulJsonRpcResponse } from "../../../../src/internal/util/jsonrpc";
+import { expectHardhatError } from "../../../helpers/errors";
 
 const TOO_MANY_REQUEST_STATUS = 429;
 
@@ -27,6 +29,20 @@ describe("HttpProvider", function () {
     result: "whatever",
   };
 
+  describe("constructor()", function () {
+    it("should throw an error if network or forking URL is an empty string", async function () {
+      expectHardhatError(() => {
+        const emptyURL = "";
+        new HttpProvider(emptyURL, networkName, {}, 20000);
+      }, ERRORS.NETWORK.EMPTY_URL);
+
+      expectHardhatError(() => {
+        const emptyURLwithWhitespace = " ";
+        new HttpProvider(emptyURLwithWhitespace, networkName, {}, 20000);
+      }, ERRORS.NETWORK.EMPTY_URL);
+    });
+  });
+
   describe("request()", function () {
     it("should call mock pool's request()", async function () {
       const mockPool = makeMockPool(url);