diff --git a/package-lock.json b/package-lock.json
index 1f47d9b9..3d91cd05 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -15,7 +15,6 @@
                 "clsx": "^2.1.0",
                 "jwt-decode": "^4.0.0",
                 "localized-countries": "^2.0.0",
-                "memoize-one": "^6.0.0",
                 "oidc-client": "^1.11.5",
                 "prop-types": "^15.8.1",
                 "react-beautiful-dnd": "^13.1.1",
@@ -12919,11 +12918,6 @@
                 "tmpl": "1.0.5"
             }
         },
-        "node_modules/memoize-one": {
-            "version": "6.0.0",
-            "resolved": "https://registry.npmjs.org/memoize-one/-/memoize-one-6.0.0.tgz",
-            "integrity": "sha512-rkpe71W0N0c0Xz6QD0eJETuWAJGnJ9afsl1srmwPrI+yBCkge5EycXXbYRyvL29zZVUWQCY7InPRCv3GDXuZNw=="
-        },
         "node_modules/merge-stream": {
             "version": "2.0.0",
             "resolved": "https://registry.npmjs.org/merge-stream/-/merge-stream-2.0.0.tgz",
diff --git a/package.json b/package.json
index 7e205ca7..09c97e5f 100644
--- a/package.json
+++ b/package.json
@@ -34,7 +34,6 @@
         "clsx": "^2.1.0",
         "jwt-decode": "^4.0.0",
         "localized-countries": "^2.0.0",
-        "memoize-one": "^6.0.0",
         "oidc-client": "^1.11.5",
         "prop-types": "^15.8.1",
         "react-beautiful-dnd": "^13.1.1",
diff --git a/src/components/authentication/SignInCallbackHandler.tsx b/src/components/authentication/SignInCallbackHandler.tsx
index 59e35507..c956222c 100644
--- a/src/components/authentication/SignInCallbackHandler.tsx
+++ b/src/components/authentication/SignInCallbackHandler.tsx
@@ -6,7 +6,7 @@
  */
 
 import { useEffect } from 'react';
-import { UserManager } from 'oidc-client';
+import type { UserManager } from 'oidc-client';
 
 export interface SignInCallbackHandlerProps {
     userManager: UserManager | null;
diff --git a/src/components/authentication/SilentRenewCallbackHandler.tsx b/src/components/authentication/SilentRenewCallbackHandler.tsx
index 8e2e8cd5..37152ed2 100644
--- a/src/components/authentication/SilentRenewCallbackHandler.tsx
+++ b/src/components/authentication/SilentRenewCallbackHandler.tsx
@@ -6,7 +6,7 @@
  */
 
 import { useEffect } from 'react';
-import { UserManager } from 'oidc-client';
+import type { UserManager } from 'oidc-client';
 
 export interface SilentRenewCallbackHandlerProps {
     userManager: UserManager | null;
diff --git a/src/components/authentication/authenticationType.ts b/src/components/authentication/authenticationType.ts
index 5b88fe8d..b74be8f8 100644
--- a/src/components/authentication/authenticationType.ts
+++ b/src/components/authentication/authenticationType.ts
@@ -5,7 +5,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
-import { UserManager } from 'oidc-client';
+import type { UserManager } from 'oidc-client';
 import { Dispatch } from 'react';
 import { NavigateFunction, Location } from 'react-router-dom';
 import { AuthenticationActions } from '../../redux/actions/authActions';
diff --git a/src/components/authentication/utils/authService.ts b/src/components/authentication/utils/authService.ts
index 77f97b1e..71651d5a 100644
--- a/src/components/authentication/utils/authService.ts
+++ b/src/components/authentication/utils/authService.ts
@@ -39,8 +39,13 @@ type CustomUserManager = UserManager & {
     };
 };
 
+declare global {
+    interface Window {
+        OIDCLog?: Log;
+    }
+}
+
 // set as a global variable to allow log level configuration at runtime
-// @ts-ignore
 window.OIDCLog = Log;
 
 const hackAuthorityKey = 'oidc.hack.authority';
@@ -69,9 +74,8 @@ function reload() {
 
 function reloadTimerOnExpiresIn(user: User, userManager: UserManager, expiresIn: number) {
     // Not allowed by TS because expires_in is supposed to be readonly
-    // @ts-ignore
-    // eslint-disable-next-line no-param-reassign
-    user.expires_in = expiresIn;
+    // @ts-expect-error TS2540: Cannot assign to expires_in because it is a read-only property.
+    user.expires_in = expiresIn; // eslint-disable-line no-param-reassign
     userManager.storeUser(user).then(() => {
         userManager.getUser();
     });
diff --git a/src/components/authentication/utils/userManagerMock.ts b/src/components/authentication/utils/userManagerMock.ts
index 47531a41..121d82ca 100644
--- a/src/components/authentication/utils/userManagerMock.ts
+++ b/src/components/authentication/utils/userManagerMock.ts
@@ -8,33 +8,38 @@
 /* eslint-disable max-classes-per-file, class-methods-use-this */
 
 import {
-    MetadataService,
-    SigninRequest,
-    SigninResponse,
-    SignoutRequest,
-    SignoutResponse,
-    User,
+    type MetadataService,
+    type OidcClientSettings,
+    type Profile,
+    type SessionStatus,
+    type SigninRequest,
+    type SigninResponse,
+    type SignoutRequest,
+    type SignoutResponse,
+    type User,
     UserManager,
     UserManagerEvents,
-    UserManagerSettings,
+    type UserManagerSettings,
 } from 'oidc-client';
 
 class Events implements UserManagerEvents {
-    userLoadedCallbacks: ((data: User) => void)[] = [];
+    public userLoadedCallbacks: UserManagerEvents.UserLoadedCallback[] = [];
 
-    addUserLoaded(callback: (data: User) => void) {
-        this.userLoadedCallbacks.push(callback);
-    }
+    load() {}
 
-    addSilentRenewError() {
-        // Nothing to do
-    }
+    unload() {}
 
-    load(/* container: User */) {
-        // not implemented
-    }
+    addAccessTokenExpiring() {}
 
-    unload() {}
+    removeAccessTokenExpiring() {}
+
+    addAccessTokenExpired() {}
+
+    removeAccessTokenExpired() {}
+
+    addUserLoaded(callback: UserManagerEvents.UserLoadedCallback) {
+        this.userLoadedCallbacks.push(callback);
+    }
 
     removeUserLoaded() {}
 
@@ -42,6 +47,8 @@ class Events implements UserManagerEvents {
 
     removeUserUnloaded() {}
 
+    addSilentRenewError() {}
+
     removeSilentRenewError() {}
 
     addUserSignedIn() {}
@@ -55,23 +62,15 @@ class Events implements UserManagerEvents {
     addUserSessionChanged() {}
 
     removeUserSessionChanged() {}
-
-    addAccessTokenExpiring() {}
-
-    removeAccessTokenExpiring() {}
-
-    addAccessTokenExpired() {}
-
-    removeAccessTokenExpired() {}
 }
 
 export class UserManagerMock implements UserManager {
-    settings;
+    events: Events;
 
-    events;
+    readonly settings: OidcClientSettings;
 
-    user: User = {
-        profile: {
+    private static readonly user = Object.freeze<User>({
+        profile: Object.freeze<Profile>({
             name: 'John Doe',
             email: 'Jhon.Doe@rte-france.com',
             iss: '',
@@ -79,7 +78,7 @@ export class UserManagerMock implements UserManager {
             aud: '',
             exp: Number.MAX_SAFE_INTEGER,
             iat: 0,
-        },
+        }),
         id_token:
             'eyJ0eXAiOiJKV1QiLCJhbGciOiJSUzI1NiIsImtpZCI6IllNRUxIVDBndmIwbXhvU0RvWWZvbWpxZmpZVSJ9.eyJhdWQiOiI5YzQwMjQ2MS1iMmFiLTQ3NjctOWRiMy02Njg1OWJiMGZjZDAiLCJpc3MiOiJodHRwczovL2' +
             'xvZ2luLm1pY3Jvc29mdG9ubGluZS5jb20vNzUwMmRhZDUtZDY0Yy00NmM3LTlkNDctYjE2ZjU4MGZjZmE5L3YyLjAiLCJpYXQiOjE1ODUzMzEyNDksIm5iZiI6MTU4NTMzMTI0OSwiZXhwIjoyNTg1MzM1MTQ5LCJhaW8iOiJBV1FB' +
@@ -110,132 +109,123 @@ export class UserManagerMock implements UserManager {
         expired: false,
         state: null,
         toStorageString: () => 'Mock of UserManager',
-    };
+    });
+
+    readonly metadataService = null as unknown as MetadataService;
 
-    readonly metadataService: MetadataService = null as unknown as MetadataService;
+    private static readonly STORAGE_KEY = 'powsybl-gridsuite-mock-user';
 
     constructor(settings: UserManagerSettings) {
         this.settings = settings;
         this.events = new Events();
     }
 
-    // eslint-disable-next-line class-methods-use-this
-    getUser() {
-        return Promise.resolve(JSON.parse(sessionStorage.getItem('powsybl-gridsuite-mock-user') ?? 'null'));
+    async getUser() {
+        return JSON.parse(sessionStorage.getItem(UserManagerMock.STORAGE_KEY) ?? 'null') as User | null;
     }
 
-    async signinSilent(): Promise<User> {
+    async signinSilent() {
         console.info('signinSilent..............');
-        const localStorageUser = JSON.parse(localStorage.getItem('powsybl-gridsuite-mock-user') ?? 'null');
+        const localStorageUser = JSON.parse(localStorage.getItem(UserManagerMock.STORAGE_KEY) ?? 'null') as User | null;
         if (localStorageUser === null) {
             throw new Error('End-User authentication required');
         }
-        sessionStorage.setItem('powsybl-gridsuite-mock-user', JSON.stringify(localStorageUser));
+        sessionStorage.setItem(UserManagerMock.STORAGE_KEY, JSON.stringify(localStorageUser));
         this.events.userLoadedCallbacks.forEach((c) => c(localStorageUser));
         return localStorageUser;
     }
 
-    // eslint-disable-next-line class-methods-use-this
     signinSilentCallback() {
         console.error('Unsupported, iframe signinSilentCallback in UserManagerMock (dev mode)');
         return Promise.reject();
     }
 
-    signinRedirect() {
-        localStorage.setItem('powsybl-gridsuite-mock-user', JSON.stringify(this.user));
+    async signinRedirect() {
+        localStorage.setItem(UserManagerMock.STORAGE_KEY, JSON.stringify(UserManagerMock.user));
         window.location.href = './sign-in-callback';
-        return Promise.resolve();
     }
 
-    // eslint-disable-next-line class-methods-use-this
-    signoutRedirect() {
-        sessionStorage.removeItem('powsybl-gridsuite-mock-user');
-        localStorage.removeItem('powsybl-gridsuite-mock-user');
+    async signoutRedirect() {
+        sessionStorage.removeItem(UserManagerMock.STORAGE_KEY);
+        localStorage.removeItem(UserManagerMock.STORAGE_KEY);
         window.location.href = '.';
-        return Promise.resolve();
     }
 
-    signinRedirectCallback() {
-        sessionStorage.setItem('powsybl-gridsuite-mock-user', JSON.stringify(this.user));
-        this.events.userLoadedCallbacks.forEach((c) => c(this.user));
-        return Promise.resolve(this.user);
+    async signinRedirectCallback() {
+        sessionStorage.setItem(UserManagerMock.STORAGE_KEY, JSON.stringify(UserManagerMock.user));
+        this.events.userLoadedCallbacks.forEach((c) => c(UserManagerMock.user));
+        return UserManagerMock.user;
     }
 
-    clearStaleState() {
-        return Promise.resolve();
+    async clearStaleState() {
+        // do nothing (@typescript-eslint/no-empty-function).
     }
 
-    storeUser() {
-        return Promise.resolve();
+    async storeUser() {
+        // do nothing (@typescript-eslint/no-empty-function).
     }
 
-    removeUser() {
-        return Promise.resolve();
+    async removeUser() {
+        // do nothing (@typescript-eslint/no-empty-function).
     }
 
-    signinPopup() {
-        return Promise.resolve(this.user);
+    async signinPopup() {
+        return UserManagerMock.user;
     }
 
-    signinPopupCallback() {
-        return Promise.resolve(undefined);
+    async signinPopupCallback() {
+        return undefined;
     }
 
-    signoutRedirectCallback() {
-        return Promise.resolve({} as SignoutResponse);
+    async signoutRedirectCallback() {
+        return {} as SignoutResponse;
     }
 
-    signoutPopup() {
-        return Promise.resolve();
+    async signoutPopup() {
+        // do nothing (@typescript-eslint/no-empty-function).
     }
 
-    signoutPopupCallback() {
-        return Promise.resolve();
+    async signoutPopupCallback() {
+        // do nothing (@typescript-eslint/no-empty-function).
     }
 
-    signinCallback() {
-        return Promise.resolve(this.user);
+    async signinCallback() {
+        return UserManagerMock.user;
     }
 
-    signoutCallback() {
-        return Promise.resolve(undefined);
+    async signoutCallback() {
+        return undefined;
     }
 
-    querySessionStatus() {
-        return Promise.resolve({
+    async querySessionStatus() {
+        return {
             session_state: '',
             sub: '',
             sid: undefined,
-        });
+        } satisfies SessionStatus;
     }
 
-    revokeAccessToken() {
-        return Promise.resolve();
+    async revokeAccessToken() {
+        // do nothing (@typescript-eslint/no-empty-function).
     }
 
-    startSilentRenew() {
-        return Promise.resolve();
-    }
+    startSilentRenew() {}
 
-    stopSilentRenew() {
-        return Promise.resolve();
-    }
+    stopSilentRenew() {}
 
-    createSigninRequest() {
-        return Promise.resolve({} as SigninRequest);
+    async createSigninRequest() {
+        return {} as SigninRequest;
     }
 
-    processSigninResponse() {
-        return Promise.resolve({} as SigninResponse);
+    async processSigninResponse() {
+        return {} as SigninResponse;
     }
 
-    createSignoutRequest() {
-        return Promise.resolve({} as SignoutRequest);
+    async createSignoutRequest() {
+        return {} as SignoutRequest;
     }
 
-    processSignoutResponse() {
-        return Promise.resolve({} as SignoutResponse);
+    async processSignoutResponse() {
+        return {} as SignoutResponse;
     }
 }
-
-export default UserManagerMock;
diff --git a/src/components/cardErrorBoundary/CardErrorBoundary.tsx b/src/components/cardErrorBoundary/CardErrorBoundary.tsx
index 9684573d..41143563 100644
--- a/src/components/cardErrorBoundary/CardErrorBoundary.tsx
+++ b/src/components/cardErrorBoundary/CardErrorBoundary.tsx
@@ -18,12 +18,12 @@ import {
     CardHeader,
     Collapse,
     IconButton,
-    IconButtonProps,
+    type IconButtonProps,
+    styled,
     Theme,
     Typography,
-    styled,
 } from '@mui/material';
-import { Component, ErrorInfo, ReactNode } from 'react';
+import { Component, type ErrorInfo, type PropsWithChildren } from 'react';
 import { FormattedMessage } from 'react-intl';
 
 export interface ExpandMoreProps extends IconButtonProps {
@@ -43,10 +43,6 @@ const ExpandMore = styled((props: ExpandMoreProps) => {
 
 // Extracted from https://react-typescript-cheatsheet.netlify.app/docs/basic/getting-started/error_boundaries/ for types
 
-interface Props {
-    children?: ReactNode;
-}
-
 type CardErrorBoundaryStateError = {
     hasError: true;
     error: Error;
@@ -60,8 +56,8 @@ type CardErrorBoundaryState = (CardErrorBoundaryStateError | CardErrorBoundarySt
     expanded: boolean;
 };
 
-export class CardErrorBoundary extends Component<Props, CardErrorBoundaryState> {
-    constructor(props: Props) {
+export class CardErrorBoundary extends Component<PropsWithChildren<{}>, CardErrorBoundaryState> {
+    constructor(props: PropsWithChildren<{}>) {
         super(props);
         this.state = {
             hasError: false,
@@ -76,18 +72,16 @@ export class CardErrorBoundary extends Component<Props, CardErrorBoundaryState>
         return { hasError: true, error };
     }
 
-    componentDidCatch(error: Error, errorInfo: ErrorInfo) {
+    override componentDidCatch(error: Error, errorInfo: ErrorInfo) {
         // You can also log the error to an error reporting service
         console.error('CardErrorBoundary caught: ', error, errorInfo);
     }
 
-    handleExpandClick() {
-        this.setState((state: CardErrorBoundaryState) => ({
-            expanded: !state.expanded,
-        }));
+    private handleExpandClick() {
+        this.setState((state: CardErrorBoundaryState) => ({ expanded: !state.expanded }));
     }
 
-    handleReloadClick() {
+    private handleReloadClick() {
         this.setState(() => ({
             hasError: false,
             expanded: false,
@@ -95,7 +89,7 @@ export class CardErrorBoundary extends Component<Props, CardErrorBoundaryState>
         }));
     }
 
-    render() {
+    override render() {
         const { hasError } = this.state;
         const { children } = this.props;
         if (hasError) {
diff --git a/src/components/flatParameters/FlatParameters.tsx b/src/components/flatParameters/FlatParameters.tsx
index 9a3b84af..a8e5284f 100644
--- a/src/components/flatParameters/FlatParameters.tsx
+++ b/src/components/flatParameters/FlatParameters.tsx
@@ -262,6 +262,7 @@ export function FlatParameters({
 
     const renderField = (param: Parameter) => {
         const fieldValue = mixInitAndDefault(param);
+        // eslint-disable-next-line default-case
         switch (param.type) {
             case 'BOOLEAN':
                 return <Switch checked={!!fieldValue} onChange={(e) => onFieldChange(e.target.checked, param)} />;
@@ -381,8 +382,6 @@ export function FlatParameters({
                         renderInput={(inputProps) => <TextField {...inputProps} variant={variant} />}
                     />
                 );
-
-            // @ts-ignore fallthrough is the expected behavior
             case 'STRING':
                 if (param.possibleValues) {
                     return (
@@ -404,20 +403,19 @@ export function FlatParameters({
                         </Select>
                     );
                 }
-            // else fallthrough to default
-            default:
-                return (
-                    <TextField
-                        sx={{ width: '50%' }}
-                        size="small"
-                        value={fieldValue || ''}
-                        onFocus={() => onUncommitted(param, true)}
-                        onBlur={() => onUncommitted(param, false)}
-                        onChange={(e) => onFieldChange(e.target.value, param)}
-                        variant={variant}
-                    />
-                );
+            // else continu/fallthrough to default
         }
+        return (
+            <TextField
+                sx={{ width: '50%' }}
+                size="small"
+                value={fieldValue || ''}
+                onFocus={() => onUncommitted(param, true)}
+                onBlur={() => onUncommitted(param, false)}
+                onChange={(e) => onFieldChange(e.target.value, param)}
+                variant={variant}
+            />
+        );
     };
 
     return (
diff --git a/src/components/inputs/reactHookForm/DirectoryItemsInput.tsx b/src/components/inputs/reactHookForm/DirectoryItemsInput.tsx
index 8054678f..b4a39444 100644
--- a/src/components/inputs/reactHookForm/DirectoryItemsInput.tsx
+++ b/src/components/inputs/reactHookForm/DirectoryItemsInput.tsx
@@ -170,7 +170,7 @@ export function DirectoryItemsInput({
             <FormControl
                 sx={mergeSx(
                     styles.formDirectoryElements1,
-                    // @ts-ignore
+                    // @ts-expect-error
                     error?.message && styles.formDirectoryElementsError
                 )}
                 error={!!error?.message}
diff --git a/src/components/inputs/reactHookForm/agGridTable/cellEditors/numericEditor.ts b/src/components/inputs/reactHookForm/agGridTable/cellEditors/numericEditor.ts
index 37f284cd..01877572 100644
--- a/src/components/inputs/reactHookForm/agGridTable/cellEditors/numericEditor.ts
+++ b/src/components/inputs/reactHookForm/agGridTable/cellEditors/numericEditor.ts
@@ -4,10 +4,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
-import { ICellEditorComp, ICellEditorParams } from 'ag-grid-community';
-
-// backspace starts the editor on Windows
-const KEY_BACKSPACE = 'Backspace';
+import { ICellEditorComp, type ICellEditorParams, KeyCode } from 'ag-grid-community';
 
 /**
  * This is a modified version of the cell editor proposed by AGGrid itself :
@@ -17,9 +14,9 @@ const KEY_BACKSPACE = 'Backspace';
  * https://www.ag-grid.com/react-data-grid/component-cell-editor/#cell-editor-example
  */
 export class NumericEditor implements ICellEditorComp {
-    eInput!: HTMLInputElement;
+    private eInput!: HTMLInputElement;
 
-    cancelBeforeStart!: boolean;
+    private cancelBeforeStart!: boolean;
 
     // gets called once before the renderer is used
     init(params: ICellEditorParams) {
@@ -27,7 +24,8 @@ export class NumericEditor implements ICellEditorComp {
         this.eInput = document.createElement('input');
         this.eInput.classList.add('numeric-input');
 
-        if (params.eventKey === KEY_BACKSPACE) {
+        // backspace starts the editor on Windows
+        if (params.eventKey === KeyCode.BACKSPACE) {
             this.eInput.value = '';
         } else if (NumericEditor.isCharNumeric(params.eventKey)) {
             this.eInput.value = params.eventKey!;
@@ -56,11 +54,11 @@ export class NumericEditor implements ICellEditorComp {
         this.cancelBeforeStart = !!isNotANumber;
     }
 
-    static isBackspace(event: KeyboardEvent) {
-        return event.key === KEY_BACKSPACE;
+    private static isBackspace(event: KeyboardEvent) {
+        return event.key === KeyCode.BACKSPACE;
     }
 
-    static isNavigationKey(event: KeyboardEvent) {
+    private static isNavigationKey(event: KeyboardEvent) {
         return event.key === 'ArrowLeft' || event.key === 'ArrowRight';
     }
 
@@ -81,24 +79,17 @@ export class NumericEditor implements ICellEditorComp {
 
     // returns the new value after editing
     getValue() {
-        const { value } = this.eInput;
         // FM : some modifications here
-        const tmp = value?.replace(',', '.') || '';
-        return parseFloat(tmp) || null;
+        const result = parseFloat(this.eInput.value.replace(',', '.'));
+        return Number.isNaN(result) ? null : result;
     }
 
-    static isCharNumeric(charStr: string | null) {
+    private static isCharNumeric(charStr: string | null) {
         // FM : I added ',' and '.'
-        return charStr && !!/\d|,|\./.test(charStr);
-    }
-
-    static isNumericKey(event: KeyboardEvent) {
-        const charStr = event.key;
-        return NumericEditor.isCharNumeric(charStr);
+        return charStr && /\d|,|\./.test(charStr);
     }
 
-    // force call when focus is leaving the editor
-    static focusOut() {
-        return true;
+    private static isNumericKey(event: KeyboardEvent) {
+        return NumericEditor.isCharNumeric(event.key);
     }
 }
diff --git a/src/components/notifications/test/NotificationsProvider.test.tsx b/src/components/notifications/test/NotificationsProvider.test.tsx
index f92a61bf..abf5c08f 100644
--- a/src/components/notifications/test/NotificationsProvider.test.tsx
+++ b/src/components/notifications/test/NotificationsProvider.test.tsx
@@ -5,13 +5,15 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 import { createRoot } from 'react-dom/client';
-import { waitFor, act } from '@testing-library/react';
+import { act, waitFor } from '@testing-library/react';
 import { afterEach, beforeEach, describe, expect, jest, test } from '@jest/globals';
 import ReconnectingWebSocket from 'reconnecting-websocket';
 import { NotificationsProvider } from '../NotificationsProvider';
 import { useNotificationsListener } from '../hooks/useNotificationsListener';
 
 jest.mock('reconnecting-websocket');
+const MockedReconnectingWebSocket = ReconnectingWebSocket as jest.MockedClass<typeof ReconnectingWebSocket>;
+
 let container: Element;
 
 declare global {
@@ -65,9 +67,8 @@ describe('NotificationsProvider', () => {
             return <p>empty</p>;
         }
 
-        const reconnectingWebSocketClass = {};
-        // @ts-ignore
-        ReconnectingWebSocket.mockImplementation(() => reconnectingWebSocketClass);
+        const reconnectingWebSocketClass = {} as jest.Mocked<ReconnectingWebSocket>;
+        MockedReconnectingWebSocket.mockImplementation(() => reconnectingWebSocketClass);
 
         act(() => {
             root.render(
@@ -76,10 +77,9 @@ describe('NotificationsProvider', () => {
                 </NotificationsProvider>
             );
         });
-        const event = { test: 'test' };
+        const event = { data: 'test' } as MessageEvent<any>;
         act(() => {
-            // @ts-ignore
-            reconnectingWebSocketClass.onmessage(event);
+            reconnectingWebSocketClass.onmessage?.(event);
         });
 
         waitFor(() => expect(eventCallback).toBeCalledWith(event));
@@ -94,9 +94,8 @@ describe('NotificationsProvider', () => {
             return <p>empty</p>;
         }
 
-        const reconnectingWebSocketClass = {};
-        // @ts-ignore
-        ReconnectingWebSocket.mockImplementation(() => reconnectingWebSocketClass);
+        const reconnectingWebSocketClass = {} as jest.Mocked<ReconnectingWebSocket>;
+        MockedReconnectingWebSocket.mockImplementation(() => reconnectingWebSocketClass);
 
         act(() => {
             root.render(
@@ -106,8 +105,7 @@ describe('NotificationsProvider', () => {
             );
         });
         act(() => {
-            // @ts-ignore
-            reconnectingWebSocketClass.onmessage({ test: 'test' });
+            reconnectingWebSocketClass.onmessage?.({ data: 'test' } as MessageEvent<any>);
         });
 
         expect(eventCallback).not.toBeCalled();
@@ -119,15 +117,14 @@ describe('NotificationsProvider', () => {
         const onOpenCallback = jest.fn();
         const reconnectingWebSocketClass = {
             onopen: onOpenCallback,
-        };
+        } as Partial<ReconnectingWebSocket> as jest.Mocked<ReconnectingWebSocket>;
         const eventCallback = jest.fn();
         function NotificationsConsumer() {
             useNotificationsListener('Fake_Key', { listenerCallbackOnReopen: eventCallback });
             return <p>empty</p>;
         }
 
-        // @ts-ignore
-        ReconnectingWebSocket.mockImplementation(() => reconnectingWebSocketClass);
+        MockedReconnectingWebSocket.mockImplementation(() => reconnectingWebSocketClass);
 
         act(() => {
             root.render(
diff --git a/src/components/topBar/TopBar.tsx b/src/components/topBar/TopBar.tsx
index 2ab7c8ad..479435ab 100644
--- a/src/components/topBar/TopBar.tsx
+++ b/src/components/topBar/TopBar.tsx
@@ -7,7 +7,6 @@
 
 import { MouseEvent, PropsWithChildren, ReactNode, useMemo, useState } from 'react';
 import { FormattedMessage } from 'react-intl';
-
 import {
     AppBar,
     Box,
@@ -33,18 +32,18 @@ import {
     Apps as AppsIcon,
     ArrowDropDown as ArrowDropDownIcon,
     ArrowDropUp as ArrowDropUpIcon,
+    Badge as BadgeIcon,
     Brightness3 as Brightness3Icon,
     Computer as ComputerIcon,
     ExitToApp as ExitToAppIcon,
     HelpOutline as HelpOutlineIcon,
-    Person as PersonIcon,
     ManageAccounts,
+    Person as PersonIcon,
     WbSunny as WbSunnyIcon,
-    Badge as BadgeIcon,
 } from '@mui/icons-material';
 import { styled } from '@mui/system';
 
-import { User } from 'oidc-client';
+import type { User } from 'oidc-client';
 import { GridLogo, GridLogoProps } from './GridLogo';
 import { AboutDialog, AboutDialogProps } from './AboutDialog';
 import { LogoutProps } from '../authentication/Logout';
@@ -156,13 +155,18 @@ const CustomListItemIcon = styled(ListItemIcon)({
     borderRadius: '25px',
 });
 
-const EN = 'EN';
-const FR = 'FR';
-
 export type GsLangUser = typeof LANG_ENGLISH | typeof LANG_FRENCH;
 export type GsLang = GsLangUser | typeof LANG_SYSTEM;
 export type GsTheme = typeof LIGHT_THEME | typeof DARK_THEME;
 
+function abbreviationFromUserName(name: string) {
+    const tab = name.split(' ').map((x) => x.charAt(0));
+    if (tab.length === 1) {
+        return tab[0];
+    }
+    return tab[0] + tab[tab.length - 1];
+}
+
 export type TopBarProps = Omit<GridLogoProps, 'onClick'> &
     Omit<LogoutProps, 'disabled'> &
     Omit<AboutDialogProps, 'open' | 'onClose'> & {
@@ -236,14 +240,6 @@ export function TopBar({
         }
     };
 
-    const abbreviationFromUserName = (name: string) => {
-        const tab = name.split(' ').map((x) => x.charAt(0));
-        if (tab.length === 1) {
-            return tab[0];
-        }
-        return tab[0] + tab[tab.length - 1];
-    };
-
     const changeTheme = (_: MouseEvent, value: GsTheme) => {
         if (onThemeClick && value !== null) {
             onThemeClick(value);
@@ -264,8 +260,7 @@ export function TopBar({
 
     const [isAboutDialogOpen, setAboutDialogOpen] = useState(false);
     const onAboutClicked = () => {
-        // @ts-ignore should be an Element, or maybe we should use null ?
-        setAnchorElSettingsMenu(false);
+        setAnchorElSettingsMenu(null);
         if (onAboutClick) {
             onAboutClick();
         } else {
@@ -292,7 +287,7 @@ export function TopBar({
     );
 
     return (
-        // @ts-ignore appBar style is not defined
+        // @ts-expect-error appBar style is not defined
         <AppBar position="static" color="default" sx={styles.appBar}>
             {user && developerMode && (
                 <MessageBanner>
@@ -369,12 +364,7 @@ export function TopBar({
                             style={anchorElSettingsMenu ? { cursor: 'initial' } : { cursor: 'pointer' }}
                         >
                             <Box component="span" sx={styles.name}>
-                                {user !== null
-                                    ? abbreviationFromUserName(
-                                          // @ts-ignore name could be undefined, how to handle this case ?
-                                          user.profile.name
-                                      )
-                                    : ''}
+                                {user.profile.name !== undefined ? abbreviationFromUserName(user.profile.name) : ''}
                             </Box>
                             {anchorElSettingsMenu ? (
                                 <ArrowDropUpIcon sx={styles.arrowIcon} />
@@ -573,14 +563,14 @@ export function TopBar({
                                                     aria-label={LANG_ENGLISH}
                                                     sx={styles.languageToggleButton}
                                                 >
-                                                    {EN}
+                                                    EN
                                                 </ToggleButton>
                                                 <ToggleButton
                                                     value={LANG_FRENCH}
                                                     aria-label={LANG_FRENCH}
                                                     sx={styles.toggleButton}
                                                 >
-                                                    {FR}
+                                                    FR
                                                 </ToggleButton>
                                             </ToggleButtonGroup>
                                         </StyledMenuItem>
diff --git a/src/components/topBar/UserInformationDialog.tsx b/src/components/topBar/UserInformationDialog.tsx
index 91cfcf97..ece8e948 100644
--- a/src/components/topBar/UserInformationDialog.tsx
+++ b/src/components/topBar/UserInformationDialog.tsx
@@ -8,7 +8,7 @@
 import { Dialog, DialogActions, DialogContent, DialogTitle, Grid, Typography } from '@mui/material';
 import { Box } from '@mui/system';
 import { FormattedMessage } from 'react-intl';
-import { User } from 'oidc-client';
+import type { User } from 'oidc-client';
 import { useEffect, useState } from 'react';
 import { CancelButton } from '../inputs/reactHookForm/utils/CancelButton';
 import fetchUserDetails from '../../services/userAdmin';
diff --git a/src/hooks/useLocalizedCountries.ts b/src/hooks/useLocalizedCountries.ts
index 0ee8b5ad..bf644538 100644
--- a/src/hooks/useLocalizedCountries.ts
+++ b/src/hooks/useLocalizedCountries.ts
@@ -7,9 +7,7 @@
 
 import { useCallback, useEffect, useMemo, useState } from 'react';
 import localizedCountries, { LocalizedCountries } from 'localized-countries';
-// @ts-ignore
 import countriesFr from 'localized-countries/data/fr';
-// @ts-ignore
 import countriesEn from 'localized-countries/data/en';
 import { LANG_ENGLISH, LANG_FRENCH, LANG_SYSTEM } from '../utils/constants/browserConstants';
 
diff --git a/src/module-localized-countries.d.ts b/src/module-localized-countries.d.ts
new file mode 100644
index 00000000..6f541a96
--- /dev/null
+++ b/src/module-localized-countries.d.ts
@@ -0,0 +1,16 @@
+/*
+ * Copyright © 2025, RTE (http://www.rte-france.com)
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+declare module 'localized-countries/data/en' {
+    const countries: Readonly<object>;
+    export default countries;
+}
+
+declare module 'localized-countries/data/fr' {
+    const countries: Readonly<object>;
+    export default countries;
+}
diff --git a/src/redux/actions/authActions.ts b/src/redux/actions/authActions.ts
index 298cf5bd..de44bbcd 100644
--- a/src/redux/actions/authActions.ts
+++ b/src/redux/actions/authActions.ts
@@ -4,7 +4,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
-import { User } from 'oidc-client';
+import type { User } from 'oidc-client';
 
 // Is redux or isn't redux, that is the question, 🎭
 export interface Action<T> {
diff --git a/src/redux/commonStore.ts b/src/redux/commonStore.ts
index d9a53c09..efc402bc 100644
--- a/src/redux/commonStore.ts
+++ b/src/redux/commonStore.ts
@@ -5,7 +5,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
-import { User } from 'oidc-client';
+import type { User } from 'oidc-client';
 
 export type CommonStoreState = {
     user: User | null;
diff --git a/src/tests/testsUtils.test.tsx b/src/tests/testsUtils.test.tsx
index 04aab50b..e007c0f8 100644
--- a/src/tests/testsUtils.test.tsx
+++ b/src/tests/testsUtils.test.tsx
@@ -6,27 +6,27 @@
  */
 
 import { render as rtlRender } from '@testing-library/react';
-import { createTheme, ThemeProvider } from '@mui/material/styles';
+import { type ReactElement } from 'react';
+import { createTheme, type Theme, ThemeProvider } from '@mui/material';
 import { IntlProvider } from 'react-intl';
-import { Theme } from '@mui/system';
 import {
-    loginEn,
-    reportViewerEn,
-    topBarEn,
-    tableEn,
-    treeviewFinderEn,
+    cardErrorBoundaryEn,
+    commonButtonEn,
+    csvEn,
+    descriptionEn,
+    directoryItemsInputEn,
     elementSearchEn,
     equipmentSearchEn,
+    equipmentsEn,
     filterEn,
     filterExpertEn,
-    descriptionEn,
-    equipmentsEn,
-    csvEn,
-    cardErrorBoundaryEn,
     flatParametersEn,
+    loginEn,
     multipleSelectionDialogEn,
-    commonButtonEn,
-    directoryItemsInputEn,
+    reportViewerEn,
+    tableEn,
+    topBarEn,
+    treeviewFinderEn,
 } from '../translations/en';
 
 const fullTrad = {
@@ -48,11 +48,13 @@ const fullTrad = {
     ...commonButtonEn,
     ...directoryItemsInputEn,
 };
-const renderWithTranslation = (ui: React.ReactElement, trad: Record<string, string> = fullTrad) => (
-    <IntlProvider locale="en" messages={trad}>
-        {ui}
-    </IntlProvider>
-);
+function renderWithTranslation(ui: ReactElement, trad: Record<string, string>) {
+    return (
+        <IntlProvider locale="en" messages={trad}>
+            {ui}
+        </IntlProvider>
+    );
+}
 
 const lightTheme = createTheme(
     {
@@ -85,19 +87,18 @@ const lightTheme = createTheme(
         },
     }
 );
-const renderWithTheme = (ui: React.ReactElement, theme: Theme = lightTheme) => (
-    <ThemeProvider theme={theme}>{ui}</ThemeProvider>
-);
+function renderWithTheme(ui: ReactElement, theme: Theme) {
+    return <ThemeProvider theme={theme}>{ui}</ThemeProvider>;
+}
 
-// eslint-disable-next-line import/prefer-default-export
 export class RenderBuilder {
-    renderWithTheme: boolean = false;
+    private renderWithTheme = false;
 
-    theme: Theme = lightTheme;
+    private theme = lightTheme;
 
-    renderWithTrad: boolean = false;
+    private renderWithTrad = false;
 
-    trad: Record<string, string> = fullTrad;
+    private trad: Record<string, string> = fullTrad;
 
     withTrad(trad?: Record<string, string>) {
         this.renderWithTrad = true;
@@ -115,7 +116,7 @@ export class RenderBuilder {
         return this;
     }
 
-    render(ui: React.ReactElement) {
+    render(ui: ReactElement) {
         let newUi = this.renderWithTrad ? renderWithTranslation(ui, this.trad) : ui;
         newUi = this.renderWithTheme ? renderWithTheme(newUi, this.theme) : newUi;
         return rtlRender(newUi);