chore: Migrate to ESLint v9

eslint.config.mjs

@@ -0,0 +1,47 @@
+import base, { createConfig } from '@metamask/eslint-config';
+import jest from '@metamask/eslint-config-jest';
+import nodejs from '@metamask/eslint-config-nodejs';
+import typescript from '@metamask/eslint-config-typescript';
+
+const config = createConfig([
+  {
+    ignores: ['dist/', 'docs/', '.yarn/'],
+  },
+
+  {
+    extends: base,
+
+    languageOptions: {
+      sourceType: 'module',
+      parserOptions: {
+        tsconfigRootDir: import.meta.dirname,
+        project: ['./tsconfig.json'],
+      },
+    },
+
+    settings: {
+      'import-x/extensions': ['.js', '.mjs'],
+    },
+  },
+
+  {
+    files: ['**/*.ts'],
+    extends: typescript,
+  },
+
+  {
+    files: ['**/*.js', '**/*.cjs'],
+    extends: nodejs,
+
+    languageOptions: {
+      sourceType: 'script',
+    },
+  },
+
+  {
+    files: ['**/*.test.ts', '**/*.test.js'],
+    extends: [jest, nodejs],
+  },
+]);
+
+export default config;

package.json

@@ -45,7 +45,7 @@
     "build": "ts-bridge --project tsconfig.build.json --clean",
     "build:docs": "typedoc",
     "lint": "yarn lint:eslint && yarn lint:constraints && yarn lint:misc --check && yarn lint:dependencies --check && yarn lint:changelog",
-    "lint:changelog": "auto-changelog validate --prettier",
+    "lint:changelog": "auto-changelog validate",
     "lint:constraints": "yarn constraints",
     "lint:dependencies": "depcheck && yarn dedupe",
     "lint:eslint": "eslint . --cache --ext js,ts",
@@ -74,39 +74,42 @@
   "devDependencies": {
     "@lavamoat/allow-scripts": "^3.0.4",
     "@lavamoat/preinstall-always-fail": "^1.0.0",
-    "@metamask/auto-changelog": "^3.1.0",
-    "@metamask/eslint-config": "^12.0.0",
-    "@metamask/eslint-config-jest": "^12.0.0",
-    "@metamask/eslint-config-nodejs": "^12.0.0",
-    "@metamask/eslint-config-typescript": "^12.0.0",
+    "@metamask/auto-changelog": "^4.1.0",
+    "@metamask/eslint-config": "^14.0.0",
+    "@metamask/eslint-config-jest": "^14.0.0",
+    "@metamask/eslint-config-nodejs": "^14.0.0",
+    "@metamask/eslint-config-typescript": "^14.0.0",
     "@ts-bridge/cli": "^0.1.2",
     "@ts-bridge/shims": "^0.1.1",
     "@types/jest": "^28.1.7",
     "@types/jest-when": "^3.5.3",
     "@types/node": "~18.18.14",
     "@types/uuid": "^9.0.8",
-    "@typescript-eslint/eslint-plugin": "^5.43.0",
-    "@typescript-eslint/parser": "^5.43.0",
+    "@typescript-eslint/eslint-plugin": "^8.26.1",
+    "@typescript-eslint/parser": "^8.26.1",
+    "@typescript-eslint/utils": "^8.26.1",
     "depcheck": "^1.4.7",
-    "eslint": "^8.44.0",
-    "eslint-config-prettier": "^8.8.0",
-    "eslint-plugin-import": "^2.27.5",
-    "eslint-plugin-jest": "^27.2.2",
-    "eslint-plugin-jsdoc": "^39.9.1",
-    "eslint-plugin-n": "^15.7.0",
-    "eslint-plugin-prettier": "^4.2.1",
-    "eslint-plugin-promise": "^6.1.1",
+    "eslint": "^9.11.0",
+    "eslint-config-prettier": "^9.1.0",
+    "eslint-import-resolver-typescript": "^3.6.3",
+    "eslint-plugin-import-x": "^4.3.0",
+    "eslint-plugin-jest": "^28.8.3",
+    "eslint-plugin-jsdoc": "^50.2.4",
+    "eslint-plugin-n": "^17.10.3",
+    "eslint-plugin-prettier": "^5.2.1",
+    "eslint-plugin-promise": "^7.1.0",
     "jest": "^29.2.2",
     "jest-it-up": "^2.0.2",
     "jest-when": "^3.6.0",
-    "prettier": "^2.7.1",
+    "prettier": "^3.3.3",
     "prettier-plugin-packagejson": "^2.3.0",
     "stdio-mock": "^1.2.0",
     "ts-jest": "^29.0.3",
     "ts-node": "^10.7.0",
     "tsd": "^0.29.0",
     "typedoc": "^0.23.15",
-    "typescript": "~5.0.4"
+    "typescript": "~5.8.2",
+    "typescript-eslint": "^8.26.1"
   },
   "packageManager": "yarn@3.8.5",
   "engines": {

src/__fixtures__/json.ts

@@ -5,7 +5,7 @@
     ['a', 2, null],
     [{ a: null, b: 2, c: [{ foo: 'bar' }] }],
   ],
   invalid: [undefined, Symbol('bar'), () => 'foo', [{ a: undefined }]],
 };
 
 export const JSON_RPC_NOTIFICATION_FIXTURES = {
@@ -1054,7 +1054,6 @@
   ],
 };
 
-/* eslint-disable @typescript-eslint/naming-convention */
 export const CHARACTER_MAP = {
   '"': '\\"',
   '\\': '\\\\',
@@ -1091,7 +1090,6 @@
   '\x1E': '\\u001e',
   '\x1F': '\\u001f',
 };
-/* eslint-enable @typescript-eslint/naming-convention */
 
 const DIRECT_CIRCULAR_REFERENCE_ARRAY: unknown[] = [];
 DIRECT_CIRCULAR_REFERENCE_ARRAY.push(DIRECT_CIRCULAR_REFERENCE_ARRAY);
@@ -1113,13 +1111,13 @@
 };
 
 const TO_JSON_CIRCULAR_REFERENCE = {
   toJSON() {
     return {};
   },
 };
 
 const CIRCULAR_REFERENCE = { prop: TO_JSON_CIRCULAR_REFERENCE };
 TO_JSON_CIRCULAR_REFERENCE.toJSON = function () {
   return CIRCULAR_REFERENCE;
 };
 
@@ -1339,7 +1337,7 @@
         levelTwo: {
           levelThree: {
             levelFour: {
               levelFive: () => {
                 return 'anything';
               },
             },
@@ -1359,7 +1357,7 @@
   },
   {
     value: [
       function () {
         return 'whatever';
       },
     ],
@@ -1476,7 +1474,7 @@
   },
   {
     value: {
       get key() {
         throw new Error();
       },
     },

src/assert.ts

@@ -43,7 +43,12 @@
  * @param message - The error message.
  * @returns The error object.
  */
-// eslint-disable-next-line @typescript-eslint/naming-convention
+
+/**
+ *
+ * @param ErrorWrapper
+ * @param message
+ */
 function getError(ErrorWrapper: AssertionErrorConstructor, message: string) {
   if (isConstructable(ErrorWrapper)) {
     return new ErrorWrapper({
@@ -81,7 +86,7 @@
 export function assert(
   value: any,
   message: string | Error = 'Assertion failed.',
-  // eslint-disable-next-line @typescript-eslint/naming-convention
+
   ErrorWrapper: AssertionErrorConstructor = AssertionError,
 ): asserts value {
   if (!value) {
@@ -108,7 +113,7 @@
   value: unknown,
   struct: Struct<Type, Schema>,
   errorPrefix = 'Assertion failed',
-  // eslint-disable-next-line @typescript-eslint/naming-convention
+
   ErrorWrapper: AssertionErrorConstructor = AssertionError,
 ): asserts value is Type {
   try {

src/collections.test.ts

@@ -103,7 +103,7 @@ describe('FrozenMap', () => {
       const frozenMap = new FrozenMap([['a', 1]]);
       frozenMap.forEach(function () {
         // @ts-expect-error: We have to shadow `this` here.
-        expect(this).toBeUndefined(); // eslint-disable-line no-invalid-this
+        expect(this).toBeUndefined();
       });
     });
 
@@ -113,7 +113,7 @@ describe('FrozenMap', () => {
       const thisArg = {};
       frozenMap.forEach(function () {
         // @ts-expect-error: We have to shadow `this` here.
-        expect(this).toBe(thisArg); // eslint-disable-line no-invalid-this
+        expect(this).toBe(thisArg);
       }, thisArg);
     });
 
@@ -317,7 +317,7 @@ describe('FrozenSet', () => {
       const frozenSet = new FrozenSet(['a']);
       frozenSet.forEach(function () {
         // @ts-expect-error: We have to shadow `this` here.
-        expect(this).toBeUndefined(); // eslint-disable-line no-invalid-this
+        expect(this).toBeUndefined();
       });
     });
 
@@ -327,7 +327,7 @@ describe('FrozenSet', () => {
       const thisArg = {};
       frozenSet.forEach(function () {
         // @ts-expect-error: We have to shadow `this` here.
-        expect(this).toBe(thisArg); // eslint-disable-line no-invalid-this
+        expect(this).toBe(thisArg);
       }, thisArg);
     });
 

src/index.ts

@@ -5,17 +5,17 @@ export * from './caip-types';
 export * from './checksum';
 export * from './coercers';
 export * from './collections';
-export * from './encryption-types';
+export type * from './encryption-types';
 export * from './errors';
 export * from './hex';
 export * from './json';
-export * from './keyring';
+export type * from './keyring';
 export * from './logging';
 export * from './misc';
 export * from './number';
-export * from './opaque';
+export type * from './opaque';
 export * from './promise';
 export * from './superstruct';
 export * from './time';
-export * from './transaction-types';
+export type * from './transaction-types';
 export * from './versions';

src/json.ts

@@ -279,7 +279,7 @@ export function getJsonSize(value: unknown): number {
 /**
  * The string '2.0'.
  */
-export const jsonrpc2 = '2.0' as const;
+export const jsonrpc2 = '2.0';
 export const JsonRpcVersionStruct = literal(jsonrpc2);
 
 /**
@@ -385,7 +385,7 @@ export function isJsonRpcNotification(
  */
 export function assertIsJsonRpcNotification(
   value: unknown,
-  // eslint-disable-next-line @typescript-eslint/naming-convention
+
   ErrorWrapper?: AssertionErrorConstructor,
 ): asserts value is JsonRpcNotification {
   assertStruct(
@@ -416,7 +416,7 @@ export function isJsonRpcRequest(value: unknown): value is JsonRpcRequest {
  */
 export function assertIsJsonRpcRequest(
   value: unknown,
-  // eslint-disable-next-line @typescript-eslint/naming-convention
+
   ErrorWrapper?: AssertionErrorConstructor,
 ): asserts value is JsonRpcRequest {
   assertStruct(
@@ -510,7 +510,7 @@ export function isPendingJsonRpcResponse(
  */
 export function assertIsPendingJsonRpcResponse(
   response: unknown,
-  // eslint-disable-next-line @typescript-eslint/naming-convention
+
   ErrorWrapper?: AssertionErrorConstructor,
 ): asserts response is PendingJsonRpcResponse {
   assertStruct(
@@ -543,7 +543,7 @@ export function isJsonRpcResponse(
  */
 export function assertIsJsonRpcResponse(
   value: unknown,
-  // eslint-disable-next-line @typescript-eslint/naming-convention
+
   ErrorWrapper?: AssertionErrorConstructor,
 ): asserts value is JsonRpcResponse {
   assertStruct(
@@ -574,7 +574,7 @@ export function isJsonRpcSuccess(value: unknown): value is JsonRpcSuccess {
  */
 export function assertIsJsonRpcSuccess(
   value: unknown,
-  // eslint-disable-next-line @typescript-eslint/naming-convention
+
   ErrorWrapper?: AssertionErrorConstructor,
 ): asserts value is JsonRpcSuccess {
   assertStruct(
@@ -605,7 +605,7 @@ export function isJsonRpcFailure(value: unknown): value is JsonRpcFailure {
  */
 export function assertIsJsonRpcFailure(
   value: unknown,
-  // eslint-disable-next-line @typescript-eslint/naming-convention
+
   ErrorWrapper?: AssertionErrorConstructor,
 ): asserts value is JsonRpcFailure {
   assertStruct(
@@ -636,7 +636,7 @@ export function isJsonRpcError(value: unknown): value is JsonRpcError {
  */
 export function assertIsJsonRpcError(
   value: unknown,
-  // eslint-disable-next-line @typescript-eslint/naming-convention
+
   ErrorWrapper?: AssertionErrorConstructor,
 ): asserts value is JsonRpcError {
   assertStruct(

src/misc.test-d.ts

@@ -8,7 +8,7 @@ import { isObject, hasProperty, getKnownPropertyNames } from './misc';
 //=============================================================================
 
 class ClassWithPrivateProperties {
-  #foo: string;
+  readonly #foo: string;
 
   bar: string;
 
@@ -47,7 +47,7 @@ if (hasProperty(constObjectType, 'foo')) {
 //=============================================================================
 
 // eslint-disable-next-line @typescript-eslint/ban-types
-const unknownObject = {} as Object;
+const unknownObject = {} as object;
 
 // Establish that `Object` is not accepted when a specific property is needed.
 expectNotAssignable<Record<'foo', unknown>>(unknownObject);
@@ -143,7 +143,6 @@ expectAssignable<RuntimeObject>({});
 
 expectAssignable<RuntimeObject>({ foo: 'foo' });
 
-// eslint-disable-next-line @typescript-eslint/naming-convention
 expectAssignable<RuntimeObject>({ 0: 'foo' });
 
 expectAssignable<RuntimeObject>({ [Symbol('foo')]: 'foo' });

src/misc.ts

@@ -97,7 +97,7 @@ export function isObject(value: unknown): value is RuntimeObject {
  */
 export const hasProperty = <
   // eslint-disable-next-line @typescript-eslint/ban-types
-  ObjectToCheck extends Object,
+  ObjectToCheck extends object,
   Property extends PropertyKey,
 >(
   objectToCheck: ObjectToCheck,

src/promise.ts

@@ -3,6 +3,7 @@
  *
  * A deferred Promise is one that can be resolved or rejected independently of
  * the Promise construction.
+ *
  * @template Result - The result type of the Promise.
  */
 export type DeferredPromise<Result = void> = {