Fix TypeScript errors

src/core/server/http/cookie_session_storage.ts

@@ -150,7 +150,7 @@ export async function createCookieSessionStorageFactory<T>(
       isHttpOnly: true,
       isSameSite: cookieOptions.sameSite === 'None' ? false : cookieOptions.sameSite ?? false,
     },
-    validateFunc: async (req, session: T | T[]) => {
+    validateFunc: async (req: Request, session: T | T[]) => {
       const result = cookieOptions.validate(session);
       if (!result.isValid) {
         clearInvalidCookie(req, result.path);

src/core/server/http/http_server.mocks.ts

@@ -87,6 +87,9 @@ function createKibanaRequestMock<P = any, Q = any, B = any>({
       method,
       url,
       route: {
+        // @ts-expect-error According to types/hapi__hapi the following settings-fields have problems:
+        // - `auth` can't be a boolean, but it can according to the @hapi/hapi source (https://github.com/hapijs/hapi/blob/v18.4.2/lib/route.js#L139)
+        // - `app` isn't a valid property, but it is and this was fixed in the types in v19.0.1 (https://github.com/DefinitelyTyped/DefinitelyTyped/pull/41968)
         settings: { tags: routeTags, auth: routeAuthRequired, app: kibanaRouteOptions },
       },
       raw: {

src/core/server/http/http_service.mock.ts

@@ -88,6 +88,7 @@ const createInternalSetupContractMock = () => {
       start: jest.fn(),
       stop: jest.fn(),
       config: jest.fn().mockReturnValue(configMock.create()),
+      // @ts-expect-error somehow it thinks that `Server` isn't a `Construtable`
     } as unknown) as jest.MockedClass<Server>,
     createCookieSessionStorageFactory: jest.fn(),
     registerOnPreRouting: jest.fn(),

src/core/server/http/router/request.test.ts

@@ -198,6 +198,7 @@ describe('KibanaRequest', () => {
       const request = httpServerMock.createRawRequest({
         route: {
           settings: {
+            // @ts-expect-error According to types/hapi__hapi, `auth` can't be a boolean, but it can according to the @hapi/hapi source (https://github.com/hapijs/hapi/blob/v18.4.2/lib/route.js#L139)
             auth,
           },
         },
@@ -211,6 +212,7 @@ describe('KibanaRequest', () => {
       const request = httpServerMock.createRawRequest({
         route: {
           settings: {
+            // @ts-expect-error According to types/hapi__hapi, the `auth` object has to have a `strategies` array, but it doesn't look like it needs it
             auth,
           },
         },
@@ -225,6 +227,7 @@ describe('KibanaRequest', () => {
       const request = httpServerMock.createRawRequest({
         route: {
           settings: {
+            // @ts-expect-error According to types/hapi__hapi, the `auth` object has to have a `strategies` array, but it doesn't look like it needs it
             auth,
           },
         },
@@ -239,6 +242,7 @@ describe('KibanaRequest', () => {
       const request = httpServerMock.createRawRequest({
         route: {
           settings: {
+            // @ts-expect-error According to types/hapi__hapi, the `auth` object has to have a `strategies` array, but it doesn't look like it needs it
             auth,
           },
         },
@@ -253,6 +257,7 @@ describe('KibanaRequest', () => {
       const request = httpServerMock.createRawRequest({
         route: {
           settings: {
+            // @ts-expect-error According to types/hapi__hapi, `auth` can't be a string, but I'm not sure that's true
             auth,
           },
         },
@@ -268,6 +273,7 @@ describe('KibanaRequest', () => {
       const request = httpServerMock.createRawRequest({
         route: {
           settings: {
+            // @ts-expect-error According to types/hapi__hapi, the `auth` object has to have a `strategies` array, but it doesn't look like it needs it
             auth,
           },
         },

src/core/server/http/router/request.ts

@@ -19,7 +19,7 @@
 
 import { URL } from 'url';
 import uuid from 'uuid';
-import { Request, RouteOptionsApp, RequestApplicationState } from '@hapi/hapi';
+import { Request, RouteOptionsApp, RequestApplicationState, RouteOptions } from '@hapi/hapi';
 import { Observable, fromEvent, merge } from 'rxjs';
 import { shareReplay, first, takeUntil } from 'rxjs/operators';
 import { RecursiveReadonly } from '@kbn/utility-types';
@@ -260,8 +260,16 @@ export class KibanaRequest<
     const socketTimeout = (request.raw.req.socket as any)?.timeout;
     const options = ({
       authRequired: this.getAuthRequired(request),
-      // some places in LP call KibanaRequest.from(request) manually. remove fallback to true before v8
-      xsrfRequired: (request.route.settings.app as KibanaRouteOptions)?.xsrfRequired ?? true,
+      // TypeScript note: Casting to `RouterOptions` to fix the following error:
+      //
+      //     Property 'app' does not exist on type 'RouteSettings'
+      //
+      // In @types/hapi__hapi v18, `request.route.settings` is of type
+      // `RouteSettings`, which doesn't have an `app` property. I think this is
+      // a mistake. In v19, the `RouteSettings` interface does have an `app`
+      // property.
+      xsrfRequired:
+        ((request.route.settings as RouteOptions).app as KibanaRouteOptions)?.xsrfRequired ?? true, // some places in LP call KibanaRequest.from(request) manually. remove fallback to true before v8
       tags: request.route.settings.tags || [],
       timeout: {
         payload: payloadTimeout,
@@ -301,6 +309,7 @@ export class KibanaRequest<
       return true;
     }
 
+    // @ts-expect-error According to @types/hapi__hapi, `route.settings` should be of type `RouteSettings`, but it seems that it's actually `RouteOptions`.
     if (authOptions === false) return false;
     throw new Error(
       `unexpected authentication options: ${JSON.stringify(authOptions)} for route: ${