Prepare for next Node LTS version - branch: main (#6497)

Author: ChristopherDedominici

.changeset/short-mangos-watch.md

@@ -0,0 +1,5 @@
+---
+"hardhat": patch
+---
+
+Added support for Node v24.

.github/workflows/hardhat-ci.yml

@@ -71,7 +71,7 @@ jobs:
       matrix:
         package: ${{ fromJson(needs.list-packages.outputs.packages) }}
         os: [ubuntu-latest, macos-latest, windows-latest]
-        node: [18, 20, 22]
+        node: [20, 22, 24]
         exclude:
           - package: hardhat-vyper
             os: windows-latest

.github/workflows/hardhat-core-ci.yml

@@ -112,9 +112,9 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        # TODO: Currently there is no @types/node for Node 22,
+        # TODO: Currently there is no @types/node for Node 24,
         # include it when it is available.
-        node: [18, 20]
+        node: [20, 22]
     steps:
       - uses: actions/checkout@v4
       - uses: ./.github/actions/setup-env

packages/hardhat-chai-matchers/test/contracts.ts

@@ -1,9 +1,12 @@
 import {
   BaseContract,
-  BaseContractMethod,
+  // eslint-disable-next-line prettier/prettier
+  type BaseContractMethod,
   ContractTransactionResponse,
-  BigNumberish,
-  AddressLike,
+  // eslint-disable-next-line prettier/prettier
+  type BigNumberish,
+  // eslint-disable-next-line prettier/prettier
+  type AddressLike,
 } from "ethers";
 
 export type MatchersContract = BaseContract & {

packages/hardhat-core/src/internal/cli/constants.ts

@@ -1 +1,7 @@
-export const SUPPORTED_NODE_VERSIONS = ["^18.0.0", "^20.0.0", "^22.0.0"];
+// TODO: Remove 18 on June 30, 2025
+export const SUPPORTED_NODE_VERSIONS = [
+  "^18.0.0",
+  "^20.0.0",
+  "^22.0.0",
+  "^24.0.0",
+];

packages/hardhat-core/src/internal/core/config/config-loading.ts

@@ -33,6 +33,7 @@ export function importCsjOrEsModule(filePath: string): any {
     // because Hardhat configs can only be CJS but a .js extension will be interpreted as ESM.
     // The kind of error we get in these cases depends on the Node.js version.
     const node20Heuristic = e.code === "ERR_REQUIRE_ESM";
+    // Also works for node v24
     const node22Heuristic =
       e.message === "module is not defined" ||
       e.message === "require is not defined";

packages/hardhat-core/test/internal/cli/is-node-version-to-warn-on.ts

@@ -11,13 +11,16 @@ describe("isNodeVersionToWarnOn", function () {
 
     assert.isFalse(isNodeVersionToWarnOn("v22.0.0"));
     assert.isFalse(isNodeVersionToWarnOn("v22.3.0"));
-  });
 
-  it("Should not warn on even newer versions even if they are unsupported", function () {
     assert.isFalse(isNodeVersionToWarnOn("v24.0.0"));
     assert.isFalse(isNodeVersionToWarnOn("v24.3.0"));
   });
 
+  it("Should not warn on even newer versions even if they are unsupported", function () {
+    assert.isFalse(isNodeVersionToWarnOn("v26.0.0"));
+    assert.isFalse(isNodeVersionToWarnOn("v26.3.0"));
+  });
+
   it("Should warn on unsupported older node versions", function () {
     assert(isNodeVersionToWarnOn("v10.0.0"));
     assert(isNodeVersionToWarnOn("v10.24.1"));

packages/hardhat-ethers/test/helpers.ts

@@ -1,5 +1,6 @@
 import { assert } from "chai";
-import { ContractRunner, Signer } from "ethers";
+// eslint-disable-next-line prettier/prettier
+import { type ContractRunner, type Signer } from "ethers";
 
 export function assertWithin(
   value: number | bigint,

packages/hardhat-ignition-core/test/execution/future-processor/utils.ts

@@ -93,14 +93,17 @@ function setupMockJsonRpcClient(
 }
 
 class MockJsonRpcClient implements JsonRpcClient {
-  private _blockNumber = 10;
+  #blockNumber = 10;
+  #transactions: { [key: string]: TransactionReceipt };
+  #sendTransaction: (transactionParams: TransactionParams) => Promise<string>;
 
   constructor(
-    private _sendTransaction: (
-      transactionParams: TransactionParams
-    ) => Promise<string>,
-    private _transactions: { [key: string]: TransactionReceipt }
-  ) {}
+    sendTransaction: (transactionParams: TransactionParams) => Promise<string>,
+    transactions: { [key: string]: TransactionReceipt }
+  ) {
+    this.#sendTransaction = sendTransaction;
+    this.#transactions = transactions;
+  }
 
   public async getChainId(): Promise<number> {
     return 31337;
@@ -113,7 +116,7 @@ class MockJsonRpcClient implements JsonRpcClient {
   }
 
   public async getLatestBlock(): Promise<Block> {
-    const blockNumber = this._blockNumber++;
+    const blockNumber = this.#blockNumber++;
 
     return {
       hash: `0xblockhash-${blockNumber}`,
@@ -152,7 +155,7 @@ class MockJsonRpcClient implements JsonRpcClient {
   public async sendTransaction(
     transactionParams: TransactionParams
   ): Promise<string> {
-    return this._sendTransaction(transactionParams);
+    return this.#sendTransaction(transactionParams);
   }
 
   public async sendRawTransaction(_presignedTx: string): Promise<string> {
@@ -181,11 +184,11 @@ class MockJsonRpcClient implements JsonRpcClient {
     txHash: string
   ): Promise<TransactionReceipt | undefined> {
     assertIgnitionInvariant(
-      txHash in this._transactions,
+      txHash in this.#transactions,
       `No transaction registered in test for the hash ${txHash}`
     );
 
-    return this._transactions[txHash];
+    return this.#transactions[txHash];
   }
 
   public async getCode(_address: string): Promise<string> {

packages/hardhat-ignition-core/test/reconciliation/helpers.ts

@@ -92,26 +92,30 @@ class MockArtifactResolver implements ArtifactResolver {
 }
 
 export class ArtifactMapResolver extends MockArtifactResolver {
-  constructor(
-    private readonly _artifactMap: { [artifactId: string]: Artifact } = {}
-  ) {
+  readonly #artifactMap: { [artifactId: string]: Artifact };
+
+  constructor(artifactMap: { [artifactId: string]: Artifact } = {}) {
     super();
+
+    this.#artifactMap = artifactMap;
   }
 
   public async loadArtifact(contractName: string): Promise<Artifact> {
-    return this._artifactMap[contractName];
+    return this.#artifactMap[contractName];
   }
 }
 
 export class ArtifactMapDeploymentLoader extends MockDeploymentLoader {
-  constructor(
-    private readonly _artifactMap: { [artifactId: string]: Artifact } = {}
-  ) {
+  readonly #artifactMap: { [artifactId: string]: Artifact };
+
+  constructor(artifactMap: { [artifactId: string]: Artifact } = {}) {
     super();
+
+    this.#artifactMap = artifactMap;
   }
 
   public async loadArtifact(contractName: string): Promise<Artifact> {
-    return this._artifactMap[contractName];
+    return this.#artifactMap[contractName];
   }
 }