feat: free resources for garbage collection

Author: schaable

v-next/hardhat-errors/src/descriptors.ts

@@ -692,6 +692,13 @@ Try using another mnemonic or deriving less keys.`,
       websiteDescription:
         "The transaction to the null address cannot have undefined data",
     },
+    PROVIDER_CLOSED: {
+      number: 722,
+      messageTemplate: "The provider has been closed.",
+      websiteTitle: "Provider closed",
+      websiteDescription:
+        "The provider your are trying to use has been closed. Please create a new one using hre.network.connect() and try again.",
+    },
   },
   KEYSTORE: {
     INVALID_KEYSTORE_FILE_FORMAT: {

v-next/hardhat/src/internal/builtin-plugins/network-manager/edr/edr-provider.ts

@@ -22,7 +22,10 @@ import {
   l1GenesisState,
   l1HardforkFromString,
 } from "@ignored/edr-optimism";
-import { assertHardhatInvariant } from "@ignored/hardhat-vnext-errors";
+import {
+  assertHardhatInvariant,
+  HardhatError,
+} from "@ignored/hardhat-vnext-errors";
 import { toSeconds } from "@ignored/hardhat-vnext-utils/date";
 import { numberToHexString } from "@ignored/hardhat-vnext-utils/hex";
 import { deepEqual } from "@ignored/hardhat-vnext-utils/lang";
@@ -109,9 +112,9 @@ interface EdrProviderConfig {
 }
 
 export class EdrProvider extends BaseProvider {
-  readonly #provider: Readonly<Provider>;
   readonly #jsonRpcRequestWrapper?: JsonRpcRequestWrapperFunction;
 
+  #provider: Provider | undefined;
   #nextRequestId = 1;
 
   /**
@@ -176,6 +179,10 @@ export class EdrProvider extends BaseProvider {
   public async request(
     requestArguments: RequestArguments,
   ): Promise<SuccessfulJsonRpcResponse["result"]> {
+    if (this.#provider === undefined) {
+      throw new HardhatError(HardhatError.ERRORS.NETWORK.PROVIDER_CLOSED);
+    }
+
     const { method, params } = requestArguments;
 
     const jsonRpcRequest = getJsonRpcRequest(
@@ -190,6 +197,11 @@ export class EdrProvider extends BaseProvider {
       jsonRpcResponse = await this.#jsonRpcRequestWrapper(
         jsonRpcRequest,
         async (request) => {
+          assertHardhatInvariant(
+            this.#provider !== undefined,
+            "The provider is not defined",
+          );
+
           const stringifiedArgs = JSON.stringify(request);
           const edrResponse =
             await this.#provider.handleRequest(stringifiedArgs);
@@ -244,7 +256,8 @@ export class EdrProvider extends BaseProvider {
   }
 
   public async close(): Promise<void> {
-    // TODO: what needs cleaned up?
+    // Clear the provider reference to help with garbage collection
+    this.#provider = undefined;
   }
 
   async #handleEdrResponse(

v-next/hardhat/src/internal/builtin-plugins/network-manager/http-provider.ts

@@ -50,9 +50,9 @@ export class HttpProvider extends BaseProvider {
   readonly #url: string;
   readonly #networkName: string;
   readonly #extraHeaders: Readonly<Record<string, string>>;
-  readonly #dispatcher: Readonly<Dispatcher>;
   readonly #jsonRpcRequestWrapper?: JsonRpcRequestWrapperFunction;
 
+  #dispatcher: Dispatcher | undefined;
   #nextRequestId = 1;
 
   /**
@@ -112,6 +112,10 @@ export class HttpProvider extends BaseProvider {
   public async request(
     requestArguments: RequestArguments,
   ): Promise<SuccessfulJsonRpcResponse["result"]> {
+    if (this.#dispatcher === undefined) {
+      throw new HardhatError(HardhatError.ERRORS.NETWORK.PROVIDER_CLOSED);
+    }
+
     const { method, params } = requestArguments;
 
     const jsonRpcRequest = getJsonRpcRequest(
@@ -150,8 +154,11 @@ export class HttpProvider extends BaseProvider {
   }
 
   public async close(): Promise<void> {
-    // See https://github.com/nodejs/undici/discussions/3522#discussioncomment-10498734
-    await this.#dispatcher.close();
+    if (this.#dispatcher !== undefined) {
+      // See https://github.com/nodejs/undici/discussions/3522#discussioncomment-10498734
+      await this.#dispatcher.close();
+      this.#dispatcher = undefined;
+    }
   }
 
   async #fetchJsonRpcResponse(

v-next/hardhat/test/internal/builtin-plugins/network-manager/http-provider.ts

@@ -4,7 +4,6 @@ import assert from "node:assert/strict";
 import { describe, it } from "node:test";
 
 import { HardhatError } from "@ignored/hardhat-vnext-errors";
-import { ensureError } from "@ignored/hardhat-vnext-utils/error";
 import { numberToHexString } from "@ignored/hardhat-vnext-utils/hex";
 import { assertRejectsWithHardhatError } from "@nomicfoundation/hardhat-test-utils";
 
@@ -498,25 +497,14 @@ describe("http-provider", () => {
       });
 
       await provider.close();
-      try {
-        await provider.request({
-          method: "eth_chainId",
-        });
-      } catch (error) {
-        ensureError(error);
 
-        assert.ok(
-          error.cause !== undefined && error.cause instanceof Error,
-          "Error does not have a cause",
-        );
-
-        // If the client is still open, the error will be a connection error
-        if (error.cause.message === "getaddrinfo ENOTFOUND loocalhost") {
-          assert.fail("Client is still open");
-        }
-
-        assert.equal(error.cause.message, "The client is destroyed");
-      }
+      await assertRejectsWithHardhatError(
+        provider.request({
+          method: "eth_chainId",
+        }),
+        HardhatError.ERRORS.NETWORK.PROVIDER_CLOSED,
+        {},
+      );
     });
   });
 });