Move the toolchain to eslint 10, typescript-eslint 8 and current plugins

eslint 8 and typescript-eslint 6 are past their support, and the webpack
dev server chain carried the dependency alerts every repository using this
package inherited. Upstream @polkadot/dev still pins the same versions, so
this leaves it on purpose.

The rules are carried over with their options, so the lint means what it
meant:

- eslint-config-standard 17 (written for eslint 8) is replaced by its 161
  rules in config/eslint.standard.js, with their options. Its 48 formatting
  rules, deprecated in eslint core, are the same rules in @stylistic;
  no-new-object and no-new-symbol are no-object-constructor and
  no-new-native-nonconstructor; import/* is import-x/*.
- eslint-plugin-import (eslint <= 9) is eslint-plugin-import-x;
  eslint-plugin-deprecation is @typescript-eslint/no-deprecated; the
  formatting rules of core, typescript-eslint and eslint-plugin-react used
  in eslint.rules.js are their @stylistic versions with the same options.
- typescript-eslint 8's preset swaps core no-unused-expressions for its own
  with default options; standard's (short circuit, ternary and tagged
  templates allowed) are carried over to it.
- eslint-plugin-react and eslint-plugin-header still call context methods
  eslint 10 removed; @eslint/compat's fixupPluginRules supplies them. The
  header rule also gets `schema: false`, as eslint 9+ rejects options for a
  rule with no schema. The original header plugin stays rather than its
  fork: it reports at the first token after leading comments, so a
  generated file's /* eslint-disable */ still covers it, as it always has.

The effective config was compared rule by rule (--print-config) for .ts,
.tsx, .spec.ts and .mjs files before and after. Every rule that left has
its successor active; option differences are eslint 10 spelling out
defaults. New rules come from the eslint 10, typescript-eslint 8 and
react-hooks 7 presets. no-inner-declarations left eslint's preset upstream.

Also current: webpack-dev-server 6, webpack-cli 7, webpack-merge 6, rollup
plugins, madge 8, gh-release 8, globals 17, espree 11; Node >= 20.19 for
the dev package, which eslint 10 requires.

In this repository the new rules found: Function types now named by
no-unsafe-function-type; optional chains, includes() and RegExp#exec where
they say the same thing; createWrapper returns Describe, so its three casts
were redundant; rootCjs.spec casts through unknown, so the lint result does
not depend on whether build/ exists. lint, build and test (149 passed) pass,
and lint leaves the tree unchanged with and without a build.

packages/dev-test/src/env/expect.ts

@@ -164,7 +164,7 @@ function assertMatchStr (value: unknown, check: string | RegExp): void {
  *
  * @see https://github.com/facebook/jest/blob/a49c88610e49a3242576160740a32a2fe11161e1/packages/expect/src/asymmetricMatchers.ts#L103-L133
  */
-// eslint-disable-next-line @typescript-eslint/ban-types
+// eslint-disable-next-line @typescript-eslint/no-unsafe-function-type
 function assertInstanceOf (value: unknown, Clazz: Function): void {
   assert.ok(
     (Clazz === Array && Array.isArray(value)) ||
@@ -188,7 +188,7 @@ function assertInstanceOf (value: unknown, Clazz: Function): void {
  * @param {string | unknown[]} value
  * @param {string} check
  */
-// eslint-disable-next-line @typescript-eslint/ban-types
+// eslint-disable-next-line @typescript-eslint/no-unsafe-function-type
 function assertIncludes (value: string | unknown[], [check, Clazz]: [string, Function]): void {
   assertInstanceOf(value, Clazz);
   assert.ok(value?.includes(check), `${value as string} does not include ${check}`);
@@ -201,7 +201,7 @@ function assertIncludes (value: string | unknown[], [check, Clazz]: [string, Fun
  **/
 export function expect () {
   const rootMatchers = {
-    // eslint-disable-next-line @typescript-eslint/ban-types
+    // eslint-disable-next-line @typescript-eslint/no-unsafe-function-type
     any: (Clazz: Function) => new Matcher(assertInstanceOf, Clazz),
     anything: () => new Matcher(assertNonNullish),
     arrayContaining: (check: string) => new Matcher(assertIncludes, [check, Array]),
@@ -229,7 +229,7 @@ export function expect () {
         toBe: (other: unknown) => assert.strictEqual(value, other),
         toBeDefined: () => assert.ok(value !== undefined),
         toBeFalsy: () => assert.ok(!value),
-        // eslint-disable-next-line @typescript-eslint/ban-types
+        // eslint-disable-next-line @typescript-eslint/no-unsafe-function-type
         toBeInstanceOf: (Clazz: Function) => assertInstanceOf(value, Clazz),
         toBeNull: (value: unknown) => assert.ok(value === null),
         toBeTruthy: () => assert.ok(value),

packages/dev-test/src/env/jest.ts

@@ -32,7 +32,7 @@ function extendMock <F extends AnyFn> (mocked: WithMock<F>) {
   //
   // Effectively the casts below ensure that our WithMock<*> aligns
   // on a high-level to what we use via private type...
-  const spy = (mocked as unknown as ReturnType<typeof mock['fn']>);
+  const spy = mocked as unknown as ReturnType<typeof mock['fn']>;
 
   return enhanceObj(enhanceObj(mocked, {
     mockImplementation: <F extends AnyFn> (fn: F): void => {

packages/dev-test/src/env/suite.ts

@@ -35,10 +35,10 @@ const MINUTE = 60 * 1000;
  * Wraps either describe or it with relevant .only, .skip, .todo & .each helpers,
  * shimming it into a Jest-compatible environment.
  *
- * @param {} fn
+ * Describe and It have the same shape, so one return type serves both.
  */
-function createWrapper <T extends WrapFn> (fn: T, defaultTimeout: number): Describe | It {
-  const wrap = (opts: WrapOpts) => (name: string, exec: () => void | Promise<void>, timeout?: number) => fn(name, { ...opts, timeout: (timeout || defaultTimeout) }, exec) as unknown as void;
+function createWrapper (fn: WrapFn, defaultTimeout: number): Describe {
+  const wrap = (opts: WrapOpts): TestFn => (name: string, exec: () => void | Promise<void>, timeout?: number) => fn(name, { ...opts, timeout: (timeout || defaultTimeout) }, exec) as unknown as void;
 
   // Ensure that we have consistent helpers on the function. These are not consistently
   // applied accross all node:test versions, latest has all, so always apply ours.
@@ -47,7 +47,7 @@ function createWrapper <T extends WrapFn> (fn: T, defaultTimeout: number): Descr
     only: wrap({ only: true }),
     skip: wrap({ skip: true }),
     todo: wrap({ todo: true })
-  }) as Describe | It;
+  });
 }
 
 /**
@@ -56,7 +56,7 @@ function createWrapper <T extends WrapFn> (fn: T, defaultTimeout: number): Descr
  **/
 export function suite (): { describe: Describe; it: It } {
   return {
-    describe: createWrapper(describe, 60 * MINUTE) as Describe,
-    it: createWrapper(it, 2 * MINUTE) as It
+    describe: createWrapper(describe, 60 * MINUTE),
+    it: createWrapper(it, 2 * MINUTE)
   };
 }

packages/dev-test/src/globals.d.ts

@@ -1,8 +1,6 @@
 // Copyright 2017-2026 @pezkuwi/dev-test authors & contributors
 // SPDX-License-Identifier: Apache-2.0
 
-/* eslint-disable no-var */
-
 import type { expect } from './env/expect.js';
 import type { jest } from './env/jest.js';
 import type { lifecycle } from './env/lifecycle.js';

packages/dev-test/src/types.ts

@@ -6,7 +6,7 @@ export type AnyFn = (...args: any[]) => any;
 
 export type BaseObj = Record<string, unknown>;
 
-// eslint-disable-next-line @typescript-eslint/ban-types
+// eslint-disable-next-line @typescript-eslint/no-unsafe-function-type
 export type BaseFn = Function;
 
 export type StubFn = (...args: unknown[]) => unknown;
@@ -25,4 +25,4 @@ export type WithMock<F extends AnyFn> = F & {
     resetCalls: () => void;
     restore: () => void;
   }
-}
+};

packages/dev-test/src/util.ts

@@ -27,7 +27,7 @@ function createStub <N extends readonly string[]> (keys: N, creator: (key: strin
     obj[key] ??= creator(key);
 
     return obj;
-  }, {}) as unknown as { [K in N[number]]: StubFn };
+  }, {}) as unknown as Record<N[number], StubFn>;
 }
 
 /**