Only enable Node lint rules for Node files

.eslintrc.js

@@ -1,9 +1,9 @@
 module.exports = {
   root: true,
-  extends: ['@metamask/eslint-config', '@metamask/eslint-config-nodejs'],
+  extends: ['@metamask/eslint-config'],
   ignorePatterns: [
     '!.eslintrc.js',
-    '!jest.config.js',
+    '!.prettierrc.js',
     'node_modules',
     '**/dist',
     '**/docs',
@@ -12,6 +12,19 @@ module.exports = {
     'scripts/create-package/package-template',
   ],
   overrides: [
+    {
+      files: [
+        '**/jest.config.js',
+        '**/jest.environment.js',
+        '**/tests/**/*.{ts,js}',
+        '*.js',
+        '*.test.{ts,js}',
+        'scripts/*.ts',
+        'scripts/create-package/*.ts',
+        'yarn.config.cjs',
+      ],
+      extends: ['@metamask/eslint-config-nodejs'],
+    },
     {
       files: ['*.test.{ts,js}', '**/tests/**/*.{ts,js}'],
       extends: ['@metamask/eslint-config-jest'],

packages/message-manager/README.md

@@ -10,6 +10,10 @@ or
 
 `npm install @metamask/message-manager`
 
+## Compatibility
+
+This package relies implicitly upon the `EventEmitter` module. This module is available natively in Node.js, but when using this package for the browser, make sure to use a polyfill such as `events`.
+
 ## Contributing
 
 This package is part of a monorepo. Instructions for contributing can be found in the [monorepo README](https://github.com/MetaMask/core#readme).

packages/message-manager/src/AbstractMessageManager.ts

@@ -2,6 +2,8 @@ import type { BaseConfig, BaseState } from '@metamask/base-controller';
 import { BaseControllerV1 } from '@metamask/base-controller';
 import type { ApprovalType } from '@metamask/controller-utils';
 import type { Hex, Json } from '@metamask/utils';
+// This package purposefully relies on Node's EventEmitter module.
+// eslint-disable-next-line import/no-nodejs-modules
 import { EventEmitter } from 'events';
 import { v1 as random } from 'uuid';
 

packages/network-controller/src/NetworkController.ts

@@ -19,13 +19,11 @@ import { errorCodes } from '@metamask/rpc-errors';
 import { createEventEmitterProxy } from '@metamask/swappable-obj-proxy';
 import type { SwappableProxy } from '@metamask/swappable-obj-proxy';
 import type { Hex } from '@metamask/utils';
-import { isStrictHexString, hasProperty, isPlainObject } from '@metamask/utils';
-import { strict as assert } from 'assert';
+import { hasProperty, isPlainObject, isStrictHexString } from '@metamask/utils';
 import type { Draft } from 'immer';
 import type { Logger } from 'loglevel';
 import { createSelector } from 'reselect';
 import * as URI from 'uri-js';
-import { inspect } from 'util';
 import { v4 as uuidV4 } from 'uuid';
 
 import { INFURA_BLOCKED_KEY, NetworkStatus } from './constants';
@@ -515,7 +513,7 @@ function getDefaultNetworkConfigurationsByChainId(): Record<
   >((obj, infuraNetworkType) => {
     const chainId = ChainId[infuraNetworkType];
     const rpcEndpointUrl =
-      // False negative - this is a string.
+      // This ESLint rule mistakenly produces an error.
       // eslint-disable-next-line @typescript-eslint/restrict-template-expressions
       `https://${infuraNetworkType}.infura.io/v3/{infuraProjectId}` as const;
 
@@ -788,9 +786,9 @@ function validateNetworkControllerState(state: NetworkState) {
 
   if (!networkClientIds.includes(state.selectedNetworkClientId)) {
     throw new Error(
-      `NetworkController state is invalid: \`selectedNetworkClientId\` ${inspect(
-        state.selectedNetworkClientId,
-      )} does not refer to an RPC endpoint within a network configuration`,
+      // This ESLint rule mistakenly produces an error.
+      // eslint-disable-next-line @typescript-eslint/restrict-template-expressions
+      `NetworkController state is invalid: \`selectedNetworkClientId\` '${state.selectedNetworkClientId}' does not refer to an RPC endpoint within a network configuration`,
     );
   }
 }
@@ -1354,19 +1352,16 @@ export class NetworkController extends BaseController<
    * removed in a future release
    */
   async setProviderType(type: InfuraNetworkType) {
-    assert.notStrictEqual(
-      type,
-      NetworkType.rpc,
-      // TODO: Either fix this lint violation or explain why it's necessary to ignore.
-      // eslint-disable-next-line @typescript-eslint/restrict-template-expressions
-      `NetworkController - cannot call "setProviderType" with type "${NetworkType.rpc}". Use "setActiveNetwork"`,
-    );
-    assert.ok(
-      isInfuraNetworkType(type),
-      // TODO: Either fix this lint violation or explain why it's necessary to ignore.
-      // eslint-disable-next-line @typescript-eslint/restrict-template-expressions
-      `Unknown Infura provider type "${type}".`,
-    );
+    if ((type as unknown) === NetworkType.rpc) {
+      throw new Error(
+        // This ESLint rule mistakenly produces an error.
+        // eslint-disable-next-line @typescript-eslint/restrict-template-expressions
+        `NetworkController - cannot call "setProviderType" with type "${NetworkType.rpc}". Use "setActiveNetwork"`,
+      );
+    }
+    if (!isInfuraNetworkType(type)) {
+      throw new Error(`Unknown Infura provider type "${String(type)}".`);
+    }
 
     await this.setActiveNetwork(type);
   }
@@ -1635,9 +1630,7 @@ export class NetworkController extends BaseController<
 
     if (existingNetworkConfiguration === undefined) {
       throw new Error(
-        `Could not update network: Cannot find network configuration for chain ${inspect(
-          chainId,
-        )}`,
+        `Could not update network: Cannot find network configuration for chain '${chainId}'`,
       );
     }
 
@@ -1802,7 +1795,7 @@ export class NetworkController extends BaseController<
       })
     ) {
       throw new Error(
-        // False negative - this is a string.
+        // This ESLint rule mistakenly produces an error.
         // eslint-disable-next-line @typescript-eslint/restrict-template-expressions
         `Could not update network: Cannot update RPC endpoints in such a way that the selected network '${this.state.selectedNetworkClientId}' would be removed without a replacement. Choose a different RPC endpoint as the selected network via the \`replacementSelectedRpcEndpointIndex\` option.`,
       );
@@ -1899,7 +1892,7 @@ export class NetworkController extends BaseController<
 
     if (existingNetworkConfiguration === undefined) {
       throw new Error(
-        `Cannot find network configuration for chain ${inspect(chainId)}`,
+        `Cannot find network configuration for chain '${chainId}'`,
       );
     }
 
@@ -2031,9 +2024,7 @@ export class NetworkController extends BaseController<
       !isSafeChainId(networkFields.chainId)
     ) {
       throw new Error(
-        `${errorMessagePrefix}: Invalid \`chainId\` ${inspect(
-          networkFields.chainId,
-        )} (must start with "0x" and not exceed the maximum)`,
+        `${errorMessagePrefix}: Invalid \`chainId\` '${networkFields.chainId}' (must start with "0x" and not exceed the maximum)`,
       );
     }
 
@@ -2046,13 +2037,13 @@ export class NetworkController extends BaseController<
       if (existingNetworkConfigurationViaChainId !== undefined) {
         if (existingNetworkConfiguration === null) {
           throw new Error(
-            // False negative - these are strings.
+            // This ESLint rule mistakenly produces an error.
             // eslint-disable-next-line @typescript-eslint/restrict-template-expressions
             `Could not add network for chain ${args.networkFields.chainId} as another network for that chain already exists ('${existingNetworkConfigurationViaChainId.name}')`,
           );
         } else {
           throw new Error(
-            // False negative - these are strings.
+            // This ESLint rule mistakenly produces an error.
             // eslint-disable-next-line @typescript-eslint/restrict-template-expressions
             `Cannot move network from chain ${existingNetworkConfiguration.chainId} to ${networkFields.chainId} as another network for that chain already exists ('${existingNetworkConfigurationViaChainId.name}')`,
           );
@@ -2082,9 +2073,9 @@ export class NetworkController extends BaseController<
     for (const rpcEndpointFields of networkFields.rpcEndpoints) {
       if (!isValidUrl(rpcEndpointFields.url)) {
         throw new Error(
-          `${errorMessagePrefix}: An entry in \`rpcEndpoints\` has invalid URL ${inspect(
-            rpcEndpointFields.url,
-          )}`,
+          // This ESLint rule mistakenly produces an error.
+          // eslint-disable-next-line @typescript-eslint/restrict-template-expressions
+          `${errorMessagePrefix}: An entry in \`rpcEndpoints\` has invalid URL '${rpcEndpointFields.url}'`,
         );
       }
       const networkClientId =
@@ -2113,13 +2104,9 @@ export class NetworkController extends BaseController<
         )
       ) {
         throw new Error(
-          `${errorMessagePrefix}: RPC endpoint '${
-            // This is a string.
-            // eslint-disable-next-line @typescript-eslint/restrict-template-expressions
-            rpcEndpointFields.url
-          }' refers to network client ${inspect(
-            networkClientId,
-          )} that does not exist`,
+          // This is a string.
+          // eslint-disable-next-line @typescript-eslint/restrict-template-expressions
+          `${errorMessagePrefix}: RPC endpoint '${rpcEndpointFields.url}' refers to network client '${networkClientId}' that does not exist`,
         );
       }
 
@@ -2149,15 +2136,19 @@ export class NetworkController extends BaseController<
             URI.equal(rpcEndpointFields.url, existingRpcEndpoint.url),
         );
         if (rpcEndpoint) {
-          throw new Error(
-            mode === 'update'
-              ? // False negative - these are strings.
-                // eslint-disable-next-line @typescript-eslint/restrict-template-expressions
-                `Could not update network to point to same RPC endpoint as existing network for chain ${networkConfiguration.chainId} ('${networkConfiguration.name}')`
-              : // False negative - these are strings.
-                // eslint-disable-next-line @typescript-eslint/restrict-template-expressions
-                `Could not add network that points to same RPC endpoint as existing network for chain ${networkConfiguration.chainId} ('${networkConfiguration.name}')`,
-          );
+          if (mode === 'update') {
+            throw new Error(
+              // This ESLint rule mistakenly produces an error.
+              // eslint-disable-next-line @typescript-eslint/restrict-template-expressions
+              `Could not update network to point to same RPC endpoint as existing network for chain ${networkConfiguration.chainId} ('${networkConfiguration.name}')`,
+            );
+          } else {
+            throw new Error(
+              // This ESLint rule mistakenly produces an error.
+              // eslint-disable-next-line @typescript-eslint/restrict-template-expressions
+              `Could not add network that points to same RPC endpoint as existing network for chain ${networkConfiguration.chainId} ('${networkConfiguration.name}')`,
+            );
+          }
         }
       }
     }
@@ -2561,7 +2552,7 @@ export class NetworkController extends BaseController<
       /* istanbul ignore if */
       if (!possibleAutoManagedNetworkClient) {
         throw new Error(
-          `No Infura network client found with ID ${inspect(networkClientId)}`,
+          `No Infura network client found with ID '${networkClientId}'`,
         );
       }
 
@@ -2573,9 +2564,7 @@ export class NetworkController extends BaseController<
         ];
 
       if (!possibleAutoManagedNetworkClient) {
-        throw new Error(
-          `No network client found with ID ${inspect(networkClientId)}`,
-        );
+        throw new Error(`No network client found with ID '${networkClientId}'`);
       }
 
       autoManagedNetworkClient = possibleAutoManagedNetworkClient;

packages/signature-controller/README.md

@@ -10,6 +10,10 @@ or
 
 `npm install @metamask/signature-controller`
 
+## Compatibility
+
+This package relies implicitly upon the `EventEmitter` module. This module is available natively in Node.js, but when using this package for the browser, make sure to use a polyfill such as `events`.
+
 ## Contributing
 
 This package is part of a monorepo. Instructions for contributing can be found in the [monorepo README](https://github.com/MetaMask/core#readme).

packages/signature-controller/src/SignatureController.ts

@@ -29,6 +29,8 @@ import {
 } from '@metamask/logging-controller';
 import type { NetworkControllerGetNetworkClientByIdAction } from '@metamask/network-controller';
 import type { Hex, Json } from '@metamask/utils';
+// This package purposefully relies on Node's EventEmitter module.
+// eslint-disable-next-line import/no-nodejs-modules
 import EventEmitter from 'events';
 import { v1 as random } from 'uuid';
 

packages/transaction-controller/README.md

@@ -10,6 +10,10 @@ or
 
 `npm install @metamask/transaction-controller`
 
+## Compatibility
+
+This package relies implicitly upon the `EventEmitter` module. This module is available natively in Node.js, but when using this package for the browser, make sure to use a polyfill such as `events`.
+
 ## Contributing
 
 This package is part of a monorepo. Instructions for contributing can be found in the [monorepo README](https://github.com/MetaMask/core#readme).

packages/transaction-controller/src/TransactionController.ts

@@ -46,6 +46,8 @@ import { errorCodes, rpcErrors, providerErrors } from '@metamask/rpc-errors';
 import type { Hex } from '@metamask/utils';
 import { add0x, hexToNumber } from '@metamask/utils';
 import { Mutex } from 'async-mutex';
+// This package purposefully relies on Node's EventEmitter module.
+// eslint-disable-next-line import/no-nodejs-modules
 import { EventEmitter } from 'events';
 import { cloneDeep, mapValues, merge, pickBy, sortBy } from 'lodash';
 import { v1 as random } from 'uuid';

packages/transaction-controller/src/helpers/GasFeePoller.ts

@@ -6,6 +6,8 @@ import type {
 import type { NetworkClientId, Provider } from '@metamask/network-controller';
 import type { Hex } from '@metamask/utils';
 import { createModuleLogger } from '@metamask/utils';
+// This package purposefully relies on Node's EventEmitter module.
+// eslint-disable-next-line import/no-nodejs-modules
 import EventEmitter from 'events';
 
 import { projectLogger } from '../logger';

packages/transaction-controller/src/helpers/IncomingTransactionHelper.ts

@@ -2,6 +2,8 @@ import type { AccountsController } from '@metamask/accounts-controller';
 import type { BlockTracker } from '@metamask/network-controller';
 import type { Hex } from '@metamask/utils';
 import { Mutex } from 'async-mutex';
+// This package purposefully relies on Node's EventEmitter module.
+// eslint-disable-next-line import/no-nodejs-modules
 import EventEmitter from 'events';
 
 import {

packages/transaction-controller/src/helpers/MethodDataHelper.ts

@@ -2,6 +2,8 @@ import type { NetworkClientId, Provider } from '@metamask/network-controller';
 import { createModuleLogger } from '@metamask/utils';
 import { Mutex } from 'async-mutex';
 import { MethodRegistry } from 'eth-method-registry';
+// This package purposefully relies on Node's EventEmitter module.
+// eslint-disable-next-line import/no-nodejs-modules
 import EventEmitter from 'events';
 
 import { projectLogger } from '../logger';

packages/transaction-controller/src/helpers/PendingTransactionTracker.ts

@@ -4,6 +4,8 @@ import type {
   BlockTracker,
   NetworkClientId,
 } from '@metamask/network-controller';
+// This package purposefully relies on Node's EventEmitter module.
+// eslint-disable-next-line import/no-nodejs-modules
 import EventEmitter from 'events';
 import { cloneDeep, merge } from 'lodash';
 

packages/user-operation-controller/README.md

@@ -10,6 +10,10 @@ or
 
 `npm install @metamask/user-operation-controller`
 
+## Compatibility
+
+This package relies implicitly upon the `EventEmitter` module. This module is available natively in Node.js, but when using this package for the browser, make sure to use a polyfill such as `events`.
+
 ## Contributing
 
 This package is part of a monorepo. Instructions for contributing can be found in the [monorepo README](https://github.com/MetaMask/core#readme).

packages/user-operation-controller/src/UserOperationController.ts

@@ -25,6 +25,8 @@ import {
   type TransactionType,
 } from '@metamask/transaction-controller';
 import { add0x } from '@metamask/utils';
+// This package purposefully relies on Node's EventEmitter module.
+// eslint-disable-next-line import/no-nodejs-modules
 import EventEmitter from 'events';
 import type { Patch } from 'immer';
 import { cloneDeep } from 'lodash';

packages/user-operation-controller/src/helpers/PendingUserOperationTracker.ts

@@ -7,6 +7,8 @@ import type {
 } from '@metamask/network-controller';
 import { BlockTrackerPollingControllerOnly } from '@metamask/polling-controller';
 import { createModuleLogger, type Hex } from '@metamask/utils';
+// This package purposefully relies on Node's EventEmitter module.
+// eslint-disable-next-line import/no-nodejs-modules
 import EventEmitter from 'events';
 
 import { projectLogger } from '../logger';

scripts/create-package/utils.test.ts

@@ -14,6 +14,7 @@ jest.mock('fs', () => ({
     mkdir: jest.fn(),
     readFile: jest.fn(),
     writeFile: jest.fn(),
+    stat: jest.fn(),
   },
 }));
 
@@ -86,7 +87,9 @@ describe('create-package/utils', () => {
         nodeVersions: '>=18.0.0',
       };
 
-      (fs.existsSync as jest.Mock).mockReturnValueOnce(false);
+      (fs.promises.stat as jest.Mock).mockResolvedValueOnce({
+        isDirectory: () => false,
+      });
 
       (fsUtils.readAllFiles as jest.Mock).mockResolvedValueOnce({
         'src/index.ts': 'export default 42;',
@@ -167,7 +170,9 @@ describe('create-package/utils', () => {
         nodeVersions: '20.0.0',
       };
 
-      (fs.existsSync as jest.Mock).mockReturnValueOnce(true);
+      (fs.promises.stat as jest.Mock).mockResolvedValueOnce({
+        isDirectory: () => true,
+      });
 
       await expect(
         finalizeAndWriteData(packageData, monorepoFileData),