chore: Upgrade to ESLint 9 and use Prettier separately (amannn#1400)

Fixes amannn#1349

eslint.config.mjs

@@ -0,0 +1,11 @@
+import {getPresets} from 'eslint-config-molindo';
+import reactCompilerPlugin from 'eslint-plugin-react-compiler';
+
+export default (await getPresets('typescript', 'react', 'vitest')).concat({
+  plugins: {
+    'react-compiler': reactCompilerPlugin
+  },
+  rules: {
+    'react-compiler/react-compiler': 'error'
+  }
+});

package.json

@@ -20,8 +20,9 @@
     "build": "rm -rf dist && rollup -c",
     "test": "TZ=Europe/Berlin vitest",
     "lint": "pnpm run lint:source && pnpm run lint:package",
-    "lint:source": "eslint src test && tsc --noEmit",
+    "lint:source": "eslint src test && tsc --noEmit && pnpm run lint:prettier",
     "lint:package": "publint && attw --pack",
+    "lint:prettier": "prettier src --check",
     "prepublishOnly": "turbo build && cp ../../README.md .",
     "postpublish": "git checkout . && rm ./README.md",
     "size": "size-limit"
@@ -102,12 +103,12 @@
     "@types/node": "^20.14.5",
     "@types/react": "^18.3.3",
     "@types/react-dom": "^18.3.0",
-    "eslint": "^8.56.0",
-    "eslint-config-molindo": "^7.0.0",
-    "eslint-plugin-deprecation": "^3.0.0",
+    "eslint": "^9.11.1",
+    "eslint-config-molindo": "^8.0.0",
     "eslint-plugin-react-compiler": "0.0.0-experimental-8e3b87c-20240822",
     "next": "^14.2.4",
     "path-to-regexp": "^6.2.2",
+    "prettier": "^3.3.3",
     "publint": "^0.2.8",
     "react": "^18.3.1",
     "react-dom": "^18.3.1",
@@ -117,5 +118,5 @@
     "typescript": "^5.5.3",
     "vitest": "^2.0.2"
   },
-  "prettier": "../../.prettierrc.json"
+  "prettier": "eslint-config-molindo/.prettierrc.json"
 }

src/middleware/getAlternateLinksHeaderValue.test.tsx

@@ -1,7 +1,7 @@
 // @vitest-environment edge-runtime
 
 import {NextRequest} from 'next/server';
-import {it, expect, describe, beforeEach, afterEach} from 'vitest';
+import {afterEach, beforeEach, describe, expect, it} from 'vitest';
 import {Pathnames} from '../routing';
 import {receiveRoutingConfig} from '../routing/config';
 import getAlternateLinksHeaderValue from './getAlternateLinksHeaderValue';

src/middleware/getAlternateLinksHeaderValue.tsx

@@ -83,10 +83,9 @@ export default function getAlternateLinksHeaderValue<
     let url: URL;
 
     if (routing.domains) {
-      const domainConfigs =
-        routing.domains.filter((cur) =>
-          isLocaleSupportedOnDomain(locale, cur)
-        ) || [];
+      const domainConfigs = routing.domains.filter((cur) =>
+        isLocaleSupportedOnDomain(locale, cur)
+      );
 
       return domainConfigs.map((domainConfig) => {
         url = new URL(normalizedUrl);

src/middleware/middleware.test.tsx

@@ -3,9 +3,9 @@
 import {RequestCookies} from 'next/dist/compiled/@edge-runtime/cookies';
 import {NextRequest, NextResponse} from 'next/server';
 import {pathToRegexp} from 'path-to-regexp';
-import {it, describe, vi, beforeEach, expect, Mock, afterEach} from 'vitest';
+import {Mock, afterEach, beforeEach, describe, expect, it, vi} from 'vitest';
 import createMiddleware from '../middleware';
-import {defineRouting, Pathnames} from '../routing';
+import {Pathnames, defineRouting} from '../routing';
 import {COOKIE_LOCALE_NAME} from '../shared/constants';
 
 vi.mock('next/server', async (importActual) => {
@@ -515,7 +515,7 @@ describe('prefix-based routing', () => {
         );
       });
 
-      it('serves requests for a non-default locale at nested paths', () => {
+      it('serves requests for a non-default locale at nested paths for "de"', () => {
         middlewareWithPathnames(createMockRequest('/de/ueber', 'de'));
         middlewareWithPathnames(createMockRequest('/de/benutzer', 'de'));
         middlewareWithPathnames(createMockRequest('/de/benutzer/1', 'de'));
@@ -552,7 +552,7 @@ describe('prefix-based routing', () => {
         );
       });
 
-      it('serves requests for a non-default locale at nested paths', () => {
+      it('serves requests for a non-default locale at nested paths for "ja"', () => {
         middlewareWithPathnames(createMockRequest('/ja/約', 'ja'));
         middlewareWithPathnames(createMockRequest('/ja/ユーザー', 'ja'));
         middlewareWithPathnames(createMockRequest('/ja/ユーザー/1', 'ja'));
@@ -695,7 +695,7 @@ describe('prefix-based routing', () => {
         );
       });
 
-      it('prioritizes static routes over dynamic and catch-all routes for the non-default locale', () => {
+      it('prioritizes static routes over dynamic and catch-all routes for the default locale', () => {
         middlewareWithPathnames(createMockRequest('/products/add', 'en'));
         middlewareWithPathnames(createMockRequest('/categories/new', 'en'));
         expect(MockedNextResponse.next).not.toHaveBeenCalled();
@@ -2256,7 +2256,7 @@ describe('prefix-based routing', () => {
         );
       });
 
-      it('redirects a dynamic internal route for the default locale', () => {
+      it('redirects a dynamic internal route for the default locale (1)', () => {
         middlewareWithPathnames(createMockRequest('/internal/22?hello', 'en'));
         expect(MockedNextResponse.next).not.toHaveBeenCalled();
         expect(MockedNextResponse.rewrite).not.toHaveBeenCalled();
@@ -2266,7 +2266,7 @@ describe('prefix-based routing', () => {
         );
       });
 
-      it('redirects a dynamic internal route for the default locale', () => {
+      it('redirects a dynamic internal route for the default locale (2)', () => {
         middlewareWithPathnames(
           createMockRequest('/internal/22/foo/bar?hello', 'en')
         );
@@ -3017,7 +3017,7 @@ describe('domain-based routing', () => {
         );
       });
 
-      it('redirects a dynamic internal route for the default locale', () => {
+      it('redirects a dynamic internal route for the default locale (1)', () => {
         middlewareWithPathnames(
           createMockRequest('/internal/22', 'en', 'http://ca.example.com')
         );
@@ -3029,7 +3029,7 @@ describe('domain-based routing', () => {
         );
       });
 
-      it('redirects a dynamic internal route for the default locale', () => {
+      it('redirects a dynamic internal route for the default locale (2)', () => {
         middlewareWithPathnames(
           createMockRequest(
             '/internal/22/foo/bar',

src/middleware/middleware.tsx

@@ -1,5 +1,5 @@
 import {NextRequest, NextResponse} from 'next/server';
-import {receiveRoutingConfig, RoutingConfig} from '../routing/config';
+import {RoutingConfig, receiveRoutingConfig} from '../routing/config';
 import {Locales, Pathnames} from '../routing/types';
 import {HEADER_LOCALE_NAME} from '../shared/constants';
 import {
@@ -12,15 +12,15 @@ import getAlternateLinksHeaderValue from './getAlternateLinksHeaderValue';
 import resolveLocale from './resolveLocale';
 import syncCookie from './syncCookie';
 import {
-  getInternalTemplate,
+  applyBasePath,
+  formatPathname,
   formatTemplatePathname,
   getBestMatchingDomain,
-  getPathnameMatch,
+  getInternalTemplate,
+  getLocaleAsPrefix,
   getNormalizedPathname,
+  getPathnameMatch,
   isLocaleSupportedOnDomain,
-  applyBasePath,
-  formatPathname,
-  getLocaleAsPrefix,
   sanitizePathname
 } from './utils';
 
@@ -36,16 +36,15 @@ export default function createMiddleware<
   const resolvedRouting = receiveRoutingConfig(routing);
   const resolvedOptions = {
     alternateLinks: options?.alternateLinks ?? routing.alternateLinks ?? true,
-    localeDetection:
-      options?.localeDetection ?? routing?.localeDetection ?? true
+    localeDetection: options?.localeDetection ?? routing.localeDetection ?? true
   };
 
   return function middleware(request: NextRequest) {
     let unsafeExternalPathname: string;
     try {
       // Resolve potential foreign symbols (e.g. /ja/%E7%B4%84 → /ja/約))
       unsafeExternalPathname = decodeURI(request.nextUrl.pathname);
-    } catch (e) {
+    } catch {
       // In case an invalid pathname is encountered, forward
       // it to Next.js which in turn responds with a 400
       return NextResponse.next();
@@ -153,7 +152,7 @@ export default function createMiddleware<
         resolvedRouting.localePrefix.mode === 'as-needed');
 
     let response;
-    let internalTemplateName: keyof AppPathnames | undefined;
+    let internalTemplateName: string | undefined;
 
     let unprefixedInternalPathname = unprefixedExternalPathname;
     if ('pathnames' in resolvedRouting) {
@@ -162,15 +161,14 @@ export default function createMiddleware<
         resolvedRouting.pathnames,
         unprefixedExternalPathname,
         locale
-      );
+      ) as [AppLocales[number] | undefined, string | undefined];
 
       if (internalTemplateName) {
         const pathnameConfig = resolvedRouting.pathnames[internalTemplateName];
         const localeTemplate: string =
           typeof pathnameConfig === 'string'
             ? pathnameConfig
-            : // @ts-expect-error -- This is fine
-              pathnameConfig[locale];
+            : pathnameConfig[locale];
 
         if (matchesPathname(localeTemplate, unprefixedExternalPathname)) {
           unprefixedInternalPathname = formatTemplatePathname(
@@ -179,14 +177,13 @@ export default function createMiddleware<
             internalTemplateName as string
           );
         } else {
-          let sourceTemplate;
+          let sourceTemplate: string;
           if (resolvedTemplateLocale) {
             // A localized pathname from another locale has matched
             sourceTemplate =
               typeof pathnameConfig === 'string'
                 ? pathnameConfig
-                : // @ts-expect-error -- This is fine
-                  pathnameConfig[resolvedTemplateLocale];
+                : pathnameConfig[resolvedTemplateLocale];
           } else {
             // An internal pathname has matched that
             // doesn't have a localized pathname
@@ -310,8 +307,8 @@ export default function createMiddleware<
         getAlternateLinksHeaderValue({
           routing: resolvedRouting,
           localizedPathnames:
-            internalTemplateName! != null && 'pathnames' in resolvedRouting
-              ? resolvedRouting.pathnames?.[internalTemplateName]
+            internalTemplateName != null && 'pathnames' in resolvedRouting
+              ? resolvedRouting.pathnames[internalTemplateName]
               : undefined,
           request,
           resolvedLocale: locale

src/middleware/resolveLocale.tsx

@@ -3,10 +3,10 @@ import Negotiator from 'negotiator';
 import {RequestCookies} from 'next/dist/server/web/spec-extension/cookies';
 import {ResolvedRoutingConfig} from '../routing/config';
 import {
-  Locales,
-  Pathnames,
+  DomainConfig,
   DomainsConfig,
-  DomainConfig
+  Locales,
+  Pathnames
 } from '../routing/types';
 import {COOKIE_LOCALE_NAME} from '../shared/constants';
 import {ResolvedMiddlewareOptions} from './config';
@@ -21,7 +21,7 @@ function findDomainFromHost<AppLocales extends Locales>(
   // Remove port (easier for local development)
   host = host?.replace(/:\d+$/, '');
 
-  if (host && domains) {
+  if (host) {
     return domains.find((cur) => cur.domain === host);
   }
 
@@ -53,7 +53,7 @@ export function getAcceptLanguageLocale<AppLocales extends Locales>(
       orderedLocales as unknown as Array<string>,
       defaultLocale
     );
-  } catch (e) {
+  } catch {
     // Invalid language
   }
 
@@ -94,12 +94,12 @@ function resolveLocaleFromPrefix<
   }
 
   // Prio 2: Use existing cookie
-  if (!locale && localeDetection && requestCookies) {
+  if (!locale && localeDetection) {
     locale = getLocaleFromCookie(requestCookies, locales);
   }
 
   // Prio 3: Use the `accept-language` header
-  if (!locale && localeDetection && requestHeaders) {
+  if (!locale && localeDetection) {
     locale = getAcceptLanguageLocale(requestHeaders, locales, defaultLocale);
   }
 
@@ -157,7 +157,7 @@ function resolveLocaleFromDomain<
   }
 
   // Prio 2: Use existing cookie
-  if (!locale && options.localeDetection && requestCookies) {
+  if (!locale && options.localeDetection) {
     const cookieLocale = getLocaleFromCookie(requestCookies, routing.locales);
     if (cookieLocale) {
       if (isLocaleSupportedOnDomain(cookieLocale, domain)) {
@@ -169,7 +169,7 @@ function resolveLocaleFromDomain<
   }
 
   // Prio 3: Use the `accept-language` header
-  if (!locale && options.localeDetection && requestHeaders) {
+  if (!locale && options.localeDetection) {
     const headerLocale = getAcceptLanguageLocale(
       requestHeaders,
       domain.locales || routing.locales,

src/middleware/utils.tsx

@@ -1,9 +1,9 @@
 import {
-  Locales,
-  LocalePrefixConfigVerbose,
   DomainConfig,
-  Pathnames,
-  DomainsConfig
+  DomainsConfig,
+  LocalePrefixConfigVerbose,
+  Locales,
+  Pathnames
 } from '../routing/types';
 import {
   getLocalePrefix,
@@ -273,9 +273,7 @@ export function getBestMatchingDomain<AppLocales extends Locales>(
 
   // Prio 3: Use alternative domain with restricted matching locale
   if (!domainConfig) {
-    domainConfig = domainsConfig.find(
-      (cur) => cur.locales != null && cur.locales.includes(locale)
-    );
+    domainConfig = domainsConfig.find((cur) => cur.locales?.includes(locale));
   }
 
   // Prio 4: Stay on the current domain if it supports all locales

src/navigation/createLocalizedPathnamesNavigation.test.tsx

@@ -1,15 +1,15 @@
 import {render, screen} from '@testing-library/react';
 import {
-  usePathname as useNextPathname,
-  useParams,
-  redirect as nextRedirect,
+  RedirectType,
   permanentRedirect as nextPermanentRedirect,
-  RedirectType
+  redirect as nextRedirect,
+  usePathname as useNextPathname,
+  useParams
 } from 'next/navigation';
 import React from 'react';
 import {renderToString} from 'react-dom/server';
-import {it, describe, vi, expect, beforeEach} from 'vitest';
-import {defineRouting, Pathnames} from '../routing';
+import {beforeEach, describe, expect, it, vi} from 'vitest';
+import {Pathnames, defineRouting} from '../routing';
 import {getRequestLocale} from '../server/react-server/RequestLocale';
 import {getLocalePrefix} from '../shared/utils';
 import createLocalizedPathnamesNavigationClient from './react-client/createLocalizedPathnamesNavigation';

src/navigation/createSharedPathnamesNavigation.test.tsx

@@ -1,14 +1,14 @@
 import {render, screen} from '@testing-library/react';
 import {
-  usePathname as useNextPathname,
-  useParams,
-  redirect as nextRedirect,
+  RedirectType,
   permanentRedirect as nextPermanentRedirect,
-  RedirectType
+  redirect as nextRedirect,
+  usePathname as useNextPathname,
+  useParams
 } from 'next/navigation';
 import React from 'react';
 import {renderToString} from 'react-dom/server';
-import {it, describe, vi, expect, beforeEach} from 'vitest';
+import {beforeEach, describe, expect, it, vi} from 'vitest';
 import {defineRouting} from '../routing';
 import {getRequestLocale} from '../server/react-server/RequestLocale';
 import {getLocalePrefix} from '../shared/utils';