diff --git a/app/utils/config.test.ts b/app/utils/config.test.ts
new file mode 100644
index 000000000..2caf194a7
--- /dev/null
+++ b/app/utils/config.test.ts
@@ -0,0 +1,15 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+import {hasReliableWebsocket} from './config';
+
+describe('Config utilities', () => {
+    test('hasReliableWebsocket', () => {
+        expect(hasReliableWebsocket('5.8.0')).toBe(false);
+        expect(hasReliableWebsocket('6.4.0', 'false')).toBe(false);
+        expect(hasReliableWebsocket('6.4.0', 'true')).toBe(true);
+        expect(hasReliableWebsocket('9.4.0', 'false')).toBe(true);
+        expect(hasReliableWebsocket('9.4.0', 'true')).toBe(true);
+        expect(hasReliableWebsocket('9.4.0')).toBe(true);
+    });
+});
diff --git a/app/utils/datetime.test.ts b/app/utils/datetime.test.ts
new file mode 100644
index 000000000..8244c2015
--- /dev/null
+++ b/app/utils/datetime.test.ts
@@ -0,0 +1,37 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+import {isSameDate, isSameMonth, isSameYear, isToday, isYesterday} from './datetime';
+
+describe('Datetime', () => {
+    test('isSameDate (isSameMonth / isSameYear)', () => {
+        expect(isSameDate(new Date('2024-03-28 02:23:27'), new Date('2025-03-28 02:23:27'))).toBe(false);
+        expect(isSameDate(new Date('2024-03-28 02:23:27'), new Date('2024-02-28 02:23:27'))).toBe(false);
+        expect(isSameDate(new Date('2024-03-28 02:23:27'), new Date('2024-03-18 02:23:27'))).toBe(false);
+        expect(isSameDate(new Date('2024-03-28 02:23:27'), new Date('2024-03-28 00:00:00'))).toBe(true);
+        expect(isSameDate(new Date('2024-03-28 02:23:27'))).toBe(false);
+        expect(isSameDate(new Date())).toBe(true);
+    });
+
+    test('isSameMonth with default', () => {
+        expect(isSameMonth(new Date('2024-03-28 02:23:27'))).toBe(false);
+        expect(isSameMonth(new Date())).toBe(true);
+    });
+
+    test('isSameYear with default', () => {
+        expect(isSameYear(new Date('2022-03-28 02:23:27'))).toBe(false);
+        expect(isSameYear(new Date())).toBe(true);
+    });
+
+    test('isToday', () => {
+        expect(isToday(new Date('2024-03-28 02:23:27'))).toBe(false);
+        expect(isToday(new Date())).toBe(true);
+    });
+
+    test('isYesteday', () => {
+        expect(isYesterday(new Date('2024-03-28 02:23:27'))).toBe(false);
+        const today = new Date();
+        today.setDate(today.getDate() - 1);
+        expect(isYesterday(today)).toBe(true);
+    });
+});
diff --git a/app/utils/error_handling.test.ts b/app/utils/error_handling.test.ts
new file mode 100644
index 000000000..b898d1f55
--- /dev/null
+++ b/app/utils/error_handling.test.ts
@@ -0,0 +1,69 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+import {Alert} from 'react-native';
+import Exception from 'react-native-exception-handler';
+
+import {dismissAllModals, dismissAllOverlays} from '@screens/navigation';
+import testHelper from '@test/test_helper';
+import * as Sentry from '@utils/sentry';
+
+import errorHandling from './error_handling';
+import * as Log from './log';
+
+jest.mock('react-native-exception-handler', () => ({
+    setJSExceptionHandler: jest.fn((callback: () => void, allowInDevMode: boolean) => {
+        if (!allowInDevMode) {
+            callback();
+        }
+    }),
+}));
+
+jest.mock('@utils/log', () => ({
+    logWarning: jest.fn(() => ''),
+}));
+
+describe('JavascriptAndNativeErrorHandler', () => {
+    const warning = jest.spyOn(Log, 'logWarning');
+    const error = 'some error';
+
+    test('Initialization', () => {
+        const setJSExceptionHandler = jest.spyOn(Exception, 'setJSExceptionHandler');
+        const initializeSentry = jest.spyOn(Sentry, 'initializeSentry');
+        errorHandling.initializeErrorHandling();
+        expect(setJSExceptionHandler).toHaveBeenCalledTimes(1);
+        expect(initializeSentry).toHaveBeenCalledTimes(1);
+        expect(setJSExceptionHandler).toHaveBeenCalledWith(errorHandling.errorHandler, false);
+    });
+
+    test('nativeErrorHander', () => {
+        const captureException = jest.spyOn(Sentry, 'captureException');
+        errorHandling.nativeErrorHandler(error);
+        expect(warning).toHaveBeenCalledTimes(1);
+        expect(warning).toHaveBeenCalledWith(`Handling native error ${error}`);
+        expect(captureException).toHaveBeenCalledTimes(1);
+        expect(captureException).toHaveBeenCalledWith(error);
+    });
+
+    test('errorHandler', async () => {
+        const captureJSException = jest.spyOn(Sentry, 'captureJSException');
+
+        errorHandling.errorHandler(null, false);
+        expect(warning).toHaveBeenCalledTimes(0);
+
+        errorHandling.errorHandler(error, true);
+        expect(warning).toHaveBeenCalledTimes(1);
+        expect(warning).toHaveBeenCalledWith('Handling Javascript error', error, true);
+        expect(captureJSException).toHaveBeenCalledTimes(1);
+        expect(captureJSException).toHaveBeenCalledWith(error, true);
+
+        const throwError = new Error(error);
+        const alert = jest.spyOn(Alert, 'alert');
+        errorHandling.errorHandler(throwError, true);
+        expect(alert?.mock?.calls?.[0]?.length).toBe(4);
+        alert?.mock.calls?.[0]?.[2]?.[0]?.onPress?.();
+        expect(dismissAllModals).toHaveBeenCalledTimes(1);
+        await testHelper.wait(20);
+        expect(dismissAllOverlays).toHaveBeenCalledTimes(1);
+    });
+});
diff --git a/app/utils/errors.test.ts b/app/utils/errors.test.ts
new file mode 100644
index 000000000..33ea2075c
--- /dev/null
+++ b/app/utils/errors.test.ts
@@ -0,0 +1,76 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+import {createIntl} from 'react-intl';
+
+import {DEFAULT_LOCALE, getTranslations} from '@i18n';
+
+import {
+    isServerError,
+    isErrorWithMessage,
+    isErrorWithDetails,
+    isErrorWithIntl,
+    isErrorWithStatusCode,
+    isErrorWithUrl,
+    getFullErrorMessage,
+} from './errors';
+
+describe('Errors', () => {
+    test('isServerError', () => {
+        expect(isServerError('error')).toBe(false);
+        expect(isServerError({message: 'some error'})).toBe(false);
+        expect(isServerError({server_error_id: 'error_id'})).toBe(true);
+    });
+
+    test('isErrorWithMessage', () => {
+        expect(isErrorWithMessage('error')).toBe(false);
+        expect(isErrorWithMessage({message: 'some error'})).toBe(true);
+        expect(isErrorWithMessage({server_error_id: 'error_id'})).toBe(false);
+    });
+
+    test('isErrorWithDetails', () => {
+        expect(isErrorWithDetails('error')).toBe(false);
+        expect(isErrorWithDetails({message: 'some error'})).toBe(false);
+        expect(isErrorWithDetails({details: 'more info'})).toBe(true);
+    });
+
+    test('isErrorWithIntl', () => {
+        expect(isErrorWithIntl('error')).toBe(false);
+        expect(isErrorWithIntl({message: 'some error'})).toBe(false);
+        expect(isErrorWithIntl({intl: {id: 'some_error_id', defaultMessage: 'message text'}})).toBe(true);
+    });
+
+    test('isErrorWithStatusCode', () => {
+        expect(isErrorWithStatusCode('error')).toBe(false);
+        expect(isErrorWithStatusCode({message: 'some error'})).toBe(false);
+        expect(isErrorWithStatusCode({status_code: 95})).toBe(true);
+    });
+
+    test('isErrorWithUrl', () => {
+        expect(isErrorWithUrl('error')).toBe(false);
+        expect(isErrorWithUrl({message: 'some error'})).toBe(false);
+        expect(isErrorWithUrl({url: 'http://localhost:8065'})).toBe(true);
+    });
+
+    test('getFullErrorMessage', () => {
+        const locale = DEFAULT_LOCALE;
+        const intl = createIntl({locale, messages: getTranslations(locale)});
+        expect(getFullErrorMessage('error', intl)).toBe('error');
+        expect(getFullErrorMessage({details: 'more info', message: 'error message'}, intl)).toBe('error message; more info');
+        expect(getFullErrorMessage({details: 'more info', message: 'error message'}, intl, 3)).toBe('error message; error message');
+        expect(getFullErrorMessage({
+            details: 'more info',
+            message: 'error message',
+            intl: {id: 'some_error_id', defaultMessage: 'message text'},
+        }, intl)).toBe('message text; more info');
+        expect(getFullErrorMessage({
+            details: 'more info',
+            message: 'error message',
+            intl: {id: 'some_error_id', defaultMessage: 'default message text'},
+        })).toBe('default message text; more info');
+
+        expect(getFullErrorMessage({
+            details: 'more info',
+        })).toBe('Unknown error; more info');
+    });
+});
diff --git a/app/utils/errors.ts b/app/utils/errors.ts
index f0f013541..4d96d371e 100644
--- a/app/utils/errors.ts
+++ b/app/utils/errors.ts
@@ -8,9 +8,8 @@ export function isServerError(obj: unknown): obj is {server_error_id?: string} {
         typeof obj === 'object' &&
         obj !== null &&
         (
-            !('server_error_id' in obj) ||
-            typeof obj.server_error_id === 'string' ||
-            typeof obj.server_error_id === 'undefined'
+            ('server_error_id' in obj) &&
+            typeof obj.server_error_id === 'string'
         )
     );
 }
@@ -56,11 +55,8 @@ export function isErrorWithUrl(obj: unknown): obj is {url?: string} {
     return (
         typeof obj === 'object' &&
         obj !== null &&
-        (
-            !('url' in obj) ||
-            typeof obj.url === 'string' ||
-            typeof obj.url === 'undefined'
-        )
+        ('url' in obj) &&
+        typeof obj.url === 'string'
     );
 }
 
diff --git a/app/utils/files.test.ts b/app/utils/files.test.ts
new file mode 100644
index 000000000..fd8de8b9b
--- /dev/null
+++ b/app/utils/files.test.ts
@@ -0,0 +1,110 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+import testHelper from '@test/test_helper';
+
+import {toMilliseconds} from './datetime';
+import {getNumberFileMenuOptions, getChannelNamesWithID, getOrderedFileInfos, getFileInfosIndexes, getOrderedGalleryItems, pathWithPrefix} from './files';
+
+import type ChannelModel from '@typings/database/models/servers/channel';
+
+describe('Files utils', () => {
+    const buildFileInfos = (): FileInfo[] => {
+        return [{
+            id: testHelper.generateId(),
+            create_at: Date.now() + toMilliseconds({days: 3, hours: 12, minutes: 8, seconds: 23}),
+            post_id: '123',
+            size: 10,
+            height: 0,
+            width: 0,
+            mime_type: 'application/pdf',
+            user_id: 'me',
+            extension: 'pdf',
+            name: 'file 3',
+            has_preview_image: false,
+        }, {
+            id: testHelper.generateId(),
+            create_at: Date.now() + toMilliseconds({days: 1, hours: 14}),
+            post_id: '123',
+            size: 10,
+            height: 100,
+            width: 100,
+            mime_type: 'image/png',
+            user_id: 'me',
+            extension: 'png',
+            name: 'file 2',
+            has_preview_image: true,
+        }, {
+            id: testHelper.generateId(),
+            create_at: Date.now() + toMilliseconds({days: 1, hours: 12, minutes: 10}),
+            post_id: '123',
+            size: 10,
+            height: 200,
+            width: 200,
+            mime_type: 'video/mp4',
+            user_id: 'me',
+            extension: 'mp4',
+            name: 'file 1',
+            has_preview_image: false,
+        }];
+    };
+
+    test('getNumberFileMenuOptions', () => {
+        expect(getNumberFileMenuOptions(false, false)).toBe(1);
+        expect(getNumberFileMenuOptions(true, false)).toBe(2);
+        expect(getNumberFileMenuOptions(false, true)).toBe(2);
+        expect(getNumberFileMenuOptions(true, true)).toBe(3);
+    });
+
+    test('getChannelNamesWithID', () => {
+        const displayNames = ['channel 1', 'channel 2', 'channel 3'];
+        const channels = displayNames.map((d, i) => ({
+            id: i.toString(),
+            displayName: d,
+        } as ChannelModel));
+        const expected = channels.reduce<Record<string, string>>((obj, channel) => {
+            obj[channel.id] = channel.displayName;
+            return obj;
+        }, {});
+
+        expect(getChannelNamesWithID(channels)).toEqual(expected);
+    });
+
+    test('getOrderedFileInfos', () => {
+        let fileInfos = buildFileInfos();
+        const result = getOrderedFileInfos(fileInfos);
+        const names = result.map((f) => f.name);
+        expect(names).toEqual(['file 3', 'file 2', 'file 1']);
+
+        // testing the variant without setting create_at
+        fileInfos = fileInfos.map((f) => ({
+            ...f,
+            create_at: undefined,
+        }));
+        const result2 = getOrderedFileInfos(fileInfos);
+        const names2 = result2.map((f) => f.name);
+        expect(names2).toEqual(names);
+    });
+
+    test('getFileInfosIndexes', () => {
+        const fileInfos = getOrderedFileInfos(buildFileInfos());
+        const result = [0, 1, 2].reduce<Record<string, number>>((obj, index) => {
+            obj[fileInfos[index].id!] = index;
+            return obj;
+        }, {});
+
+        expect(getFileInfosIndexes(fileInfos)).toEqual(result);
+    });
+
+    test('getOrderedGalleryItems', () => {
+        const fileInfos = getOrderedFileInfos(buildFileInfos());
+        const result = getOrderedGalleryItems(fileInfos);
+        const types = result.map((f) => f.type);
+        expect(types).toEqual(['file', 'image', 'video']);
+    });
+
+    test('pathWithPrefix', () => {
+        expect(pathWithPrefix('file://', 'file://something')).toEqual('file://something');
+        expect(pathWithPrefix('file://', 'something')).toEqual('file://something');
+    });
+});
diff --git a/test/setup.ts b/test/setup.ts
index 78abb3806..ca777b0bc 100644
--- a/test/setup.ts
+++ b/test/setup.ts
@@ -369,6 +369,7 @@ jest.mock('@screens/navigation', () => ({
     dismissAllModalsAndPopToScreen: jest.fn(),
     dismissAllModalsAndPopToRoot: jest.fn(),
     dismissOverlay: jest.fn(() => Promise.resolve()),
+    dismissAllOverlays: jest.fn(() => Promise.resolve()),
 }));
 
 jest.mock('@mattermost/react-native-emm', () => ({