From 490c7c10186cdc148fc980312c0e1853c0da609c Mon Sep 17 00:00:00 2001
From: Ludy87 <Ludy87@users.noreply.github.com>
Date: Thu, 25 Sep 2025 07:36:19 +0200
Subject: [PATCH] Refactor to use nullish coalescing and add missing React
 imports

Replaced many uses of logical OR (||) with nullish coalescing (??) for more accurate handling of undefined/null values. Added missing explicit React imports to various component files to ensure compatibility with tooling and future React versions. Also updated some async function calls to use 'void' for better type safety and intent clarity. Minor whitespace and formatting adjustments included.
---
 .../tools/addStamp/StampPreview.tsx           | 16 ++++++-------
 .../tools/addStamp/useAddStampOperation.ts    |  4 ++--
 .../tools/addWatermark/WatermarkImageFile.tsx |  2 +-
 .../addWatermark/WatermarkTypeSettings.tsx    |  1 +
 .../AdjustPageScaleSettings.test.tsx          |  1 +
 .../AdjustPageScaleSettings.tsx               |  1 +
 .../tools/automate/AutomationCreation.tsx     |  4 ++--
 .../tools/automate/AutomationEntry.tsx        |  2 +-
 .../tools/automate/AutomationRun.tsx          |  4 ++--
 .../tools/automate/ToolConfigurationModal.tsx |  2 +-
 .../tools/automate/ToolSelector.tsx           |  6 ++---
 .../certSign/CertificateFilesSettings.tsx     | 19 ++++++++-------
 .../certSign/CertificateFormatSettings.tsx    |  1 +
 .../certSign/CertificateTypeSettings.tsx      |  1 +
 .../certSign/SignatureAppearanceSettings.tsx  |  1 +
 .../ChangeMetadataSingleStep.tsx              |  1 +
 .../steps/AdvancedOptionsStep.tsx             |  1 +
 .../steps/CustomMetadataStep.tsx              |  1 +
 .../changeMetadata/steps/DeleteAllStep.tsx    |  1 +
 .../steps/DocumentDatesStep.tsx               |  1 +
 .../steps/StandardMetadataStep.tsx            |  1 +
 .../ChangePermissionsSettings.test.tsx        |  1 +
 .../ChangePermissionsSettings.tsx             |  1 +
 .../tools/convert/ConvertToPdfaSettings.tsx   |  2 +-
 .../components/tools/crop/CropSettings.tsx    |  6 ++---
 .../tools/flatten/FlattenSettings.tsx         |  1 +
 .../tools/merge/MergeFileSorter.test.tsx      |  1 +
 .../tools/merge/MergeSettings.test.tsx        |  1 +
 .../components/tools/ocr/LanguagePicker.tsx   |  2 +-
 .../src/components/tools/ocr/OCRSettings.tsx  |  2 +-
 .../redact/RedactAdvancedSettings.test.tsx    |  1 +
 .../tools/redact/RedactAdvancedSettings.tsx   |  1 +
 .../tools/redact/RedactModeSelector.tsx       |  1 +
 .../redact/RedactSingleStepSettings.test.tsx  |  1 +
 .../src/components/viewer/SearchInterface.tsx |  2 +-
 .../components/viewer/ThumbnailSidebar.tsx    |  2 +-
 frontend/src/contexts/FilesModalContext.tsx   | 10 +++++---
 .../tools/automate/useSavedAutomations.ts     |  4 ++--
 .../changeMetadata/useMetadataExtraction.ts   |  2 +-
 frontend/src/hooks/useAppConfig.ts            |  2 +-
 frontend/src/hooks/useEndpointConfig.ts       |  4 ++--
 .../src/hooks/useEnhancedProcessedFiles.ts    |  2 +-
 frontend/src/hooks/useIndexedDBThumbnail.ts   |  3 +--
 .../src/hooks/usePdfSignatureDetection.ts     |  2 +-
 frontend/src/hooks/useProcessedFiles.ts       |  2 +-
 frontend/src/i18n.ts                          |  2 +-
 frontend/src/i18n/config.ts                   |  6 ++---
 .../services/enhancedPDFProcessingService.ts  |  2 +-
 .../src/services/fileProcessingService.ts     |  2 +-
 frontend/src/services/fileStorage.ts          | 24 +++++++++----------
 frontend/src/services/indexedDBManager.ts     |  4 ++--
 frontend/src/services/pdfProcessingService.ts |  2 +-
 frontend/src/services/pdfWorkerManager.ts     |  6 ++---
 frontend/src/tools/AdjustPageScale.tsx        |  2 +-
 frontend/src/tools/Crop.tsx                   |  1 +
 frontend/src/tools/RemovePassword.tsx         |  1 +
 frontend/src/tools/Rotate.tsx                 |  1 +
 57 files changed, 104 insertions(+), 76 deletions(-)

diff --git a/frontend/src/components/tools/addStamp/StampPreview.tsx b/frontend/src/components/tools/addStamp/StampPreview.tsx
index 730f36b35..a6a4c178b 100644
--- a/frontend/src/components/tools/addStamp/StampPreview.tsx
+++ b/frontend/src/components/tools/addStamp/StampPreview.tsx
@@ -72,7 +72,7 @@ export default function StampPreview({ parameters, onParameterChange, file, show
         if (!cancelled) setPageSize(null);
       }
     };
-    load();
+    void load();
     return () => { cancelled = true; };
   }, [file]);
 
@@ -88,12 +88,12 @@ export default function StampPreview({ parameters, onParameterChange, file, show
         const pageNumber = Math.max(1, getFirstSelectedPage(parameters.pageNumbers));
         const pageId = `${file.name}:${file.size}:${file.lastModified}:page:${pageNumber}`;
         const thumb = await requestThumbnail(pageId, file, pageNumber);
-        if (isActive) setPageThumbnail(thumb || null);
+        if (isActive) setPageThumbnail(thumb ?? null);
       } catch {
         if (isActive) setPageThumbnail(null);
       }
     };
-    loadThumb();
+    void loadThumb();
     return () => { isActive = false; };
   }, [file, parameters.pageNumbers, requestThumbnail]);
 
@@ -189,7 +189,7 @@ export default function StampPreview({ parameters, onParameterChange, file, show
 
     draggingRef.current = {
       type,
-      startX: e.clientX - (rect?.left || 0),
+      startX: e.clientX - (rect?.left ?? 0),
       startY: (rect ? rect.bottom - e.clientY : 0), // convert to bottom-based coords
       initLeft: left,
       initBottom: bottom,
@@ -255,11 +255,11 @@ export default function StampPreview({ parameters, onParameterChange, file, show
         <div className={styles.divider} />
         <div className={styles.previewLabel}>Preview Stamp</div>
       </div>
-      <div 
-        ref={containerRef} 
+      <div
+        ref={containerRef}
         className={`${styles.container} ${styles.containerBorder} ${pageThumbnail ? styles.containerWithThumbnail : styles.containerWithoutThumbnail}`}
-        style={style.container as React.CSSProperties} 
-        onPointerMove={handlePointerMove} 
+        style={style.container as React.CSSProperties}
+        onPointerMove={handlePointerMove}
         onPointerUp={handlePointerUp}
       >
         {pageThumbnail && (
diff --git a/frontend/src/components/tools/addStamp/useAddStampOperation.ts b/frontend/src/components/tools/addStamp/useAddStampOperation.ts
index c41c440fc..48480f408 100644
--- a/frontend/src/components/tools/addStamp/useAddStampOperation.ts
+++ b/frontend/src/components/tools/addStamp/useAddStampOperation.ts
@@ -7,7 +7,7 @@ export const buildAddStampFormData = (parameters: AddStampParameters, file: File
   const formData = new FormData();
   formData.append('fileInput', file);
   formData.append('pageNumbers', parameters.pageNumbers);
-  formData.append('customMargin', parameters.customMargin || 'medium'); 
+  formData.append('customMargin', parameters.customMargin || 'medium');
   formData.append('position', String(parameters.position));
   const effectiveFontSize = parameters.fontSize;
   formData.append('fontSize', String(effectiveFontSize));
@@ -19,7 +19,7 @@ export const buildAddStampFormData = (parameters: AddStampParameters, file: File
   formData.append('alphabet', parameters.alphabet);
 
   // Stamp type and payload
-  formData.append('stampType', parameters.stampType || 'text');
+  formData.append('stampType', parameters.stampType ?? 'text');
   if (parameters.stampType === 'text') {
     formData.append('stampText', parameters.stampText);
   } else if (parameters.stampType === 'image' && parameters.stampImage) {
diff --git a/frontend/src/components/tools/addWatermark/WatermarkImageFile.tsx b/frontend/src/components/tools/addWatermark/WatermarkImageFile.tsx
index 85e723ccb..90e603f52 100644
--- a/frontend/src/components/tools/addWatermark/WatermarkImageFile.tsx
+++ b/frontend/src/components/tools/addWatermark/WatermarkImageFile.tsx
@@ -17,7 +17,7 @@ const WatermarkImageFile = ({ parameters, onParameterChange, disabled = false }:
     <Stack gap="sm">
       <FileUploadButton
         file={parameters.watermarkImage}
-        onChange={(file) => onParameterChange('watermarkImage', file || undefined)}
+        onChange={(file) => onParameterChange('watermarkImage', file ?? undefined)}
         accept="image/*"
         disabled={disabled}
         placeholder={t('watermark.settings.image.choose', 'Choose Image')}
diff --git a/frontend/src/components/tools/addWatermark/WatermarkTypeSettings.tsx b/frontend/src/components/tools/addWatermark/WatermarkTypeSettings.tsx
index 2c7548df8..142d623a4 100644
--- a/frontend/src/components/tools/addWatermark/WatermarkTypeSettings.tsx
+++ b/frontend/src/components/tools/addWatermark/WatermarkTypeSettings.tsx
@@ -1,3 +1,4 @@
+import React from "react";
 import { useTranslation } from "react-i18next";
 import ButtonSelector from "../../shared/ButtonSelector";
 
diff --git a/frontend/src/components/tools/adjustPageScale/AdjustPageScaleSettings.test.tsx b/frontend/src/components/tools/adjustPageScale/AdjustPageScaleSettings.test.tsx
index d71655cdc..52b0abbd5 100644
--- a/frontend/src/components/tools/adjustPageScale/AdjustPageScaleSettings.test.tsx
+++ b/frontend/src/components/tools/adjustPageScale/AdjustPageScaleSettings.test.tsx
@@ -1,3 +1,4 @@
+import React from 'react';
 import { describe, expect, test, vi, beforeEach } from 'vitest';
 import { render, screen } from '@testing-library/react';
 import { MantineProvider } from '@mantine/core';
diff --git a/frontend/src/components/tools/adjustPageScale/AdjustPageScaleSettings.tsx b/frontend/src/components/tools/adjustPageScale/AdjustPageScaleSettings.tsx
index 9262bcba4..3879ad954 100644
--- a/frontend/src/components/tools/adjustPageScale/AdjustPageScaleSettings.tsx
+++ b/frontend/src/components/tools/adjustPageScale/AdjustPageScaleSettings.tsx
@@ -1,3 +1,4 @@
+import React from "react";
 import { Stack, NumberInput, Select } from "@mantine/core";
 import { useTranslation } from "react-i18next";
 import { AdjustPageScaleParameters, PageSize } from "../../../hooks/tools/adjustPageScale/useAdjustPageScaleParameters";
diff --git a/frontend/src/components/tools/automate/AutomationCreation.tsx b/frontend/src/components/tools/automate/AutomationCreation.tsx
index b5e793ccb..c19092f79 100644
--- a/frontend/src/components/tools/automate/AutomationCreation.tsx
+++ b/frontend/src/components/tools/automate/AutomationCreation.tsx
@@ -1,4 +1,4 @@
-import { useState } from 'react';
+import React, { useState } from 'react';
 import { useTranslation } from 'react-i18next';
 import {
   Button,
@@ -100,7 +100,7 @@ export default function AutomationCreation({ mode, existingAutomation, onBack, o
       icon: automationIcon,
       operations: selectedTools.map(tool => ({
         operation: tool.operation,
-        parameters: tool.parameters || {}
+        parameters: tool.parameters ?? {}
       }))
     };
 
diff --git a/frontend/src/components/tools/automate/AutomationEntry.tsx b/frontend/src/components/tools/automate/AutomationEntry.tsx
index 30c280491..d68b517b5 100644
--- a/frontend/src/components/tools/automate/AutomationEntry.tsx
+++ b/frontend/src/components/tools/automate/AutomationEntry.tsx
@@ -240,7 +240,7 @@ export default function AutomationEntry({
   );
 
   // Show tooltip if there's a description OR operations to display
-  const shouldShowTooltip = description || operations.length > 0;
+  const shouldShowTooltip = description ?? operations.length > 0;
 
   return shouldShowTooltip ? (
     <Tooltip
diff --git a/frontend/src/components/tools/automate/AutomationRun.tsx b/frontend/src/components/tools/automate/AutomationRun.tsx
index 2d6bda6fc..d8f1e1a4e 100644
--- a/frontend/src/components/tools/automate/AutomationRun.tsx
+++ b/frontend/src/components/tools/automate/AutomationRun.tsx
@@ -26,7 +26,7 @@ export default function AutomationRun({ automation, onComplete, automateOperatio
   const [currentStepIndex, setCurrentStepIndex] = useState(-1);
 
   // Use the operation hook's loading state
-  const isExecuting = automateOperation?.isLoading || false;
+  const isExecuting = automateOperation?.isLoading ?? false;
   const hasResults = automateOperation?.files.length > 0 || automateOperation?.downloadUrl !== null;
 
   // Initialize execution steps from automation
@@ -194,7 +194,7 @@ export default function AutomationRun({ automation, onComplete, automateOperatio
           <Button
             leftSection={<PlayArrowIcon />}
             onClick={executeAutomation}
-            disabled={isExecuting || !selectedFiles || selectedFiles.length === 0}
+            disabled={(isExecuting ?? !selectedFiles) ?? selectedFiles.length === 0}
             loading={isExecuting}
           >
             {isExecuting
diff --git a/frontend/src/components/tools/automate/ToolConfigurationModal.tsx b/frontend/src/components/tools/automate/ToolConfigurationModal.tsx
index 4fce30b3d..ffac6a02d 100644
--- a/frontend/src/components/tools/automate/ToolConfigurationModal.tsx
+++ b/frontend/src/components/tools/automate/ToolConfigurationModal.tsx
@@ -1,4 +1,4 @@
-import { useState, useEffect } from 'react';
+import React, { useState, useEffect } from 'react';
 import { useTranslation } from 'react-i18next';
 import {
   Modal,
diff --git a/frontend/src/components/tools/automate/ToolSelector.tsx b/frontend/src/components/tools/automate/ToolSelector.tsx
index 7d5faafc5..33e43999f 100644
--- a/frontend/src/components/tools/automate/ToolSelector.tsx
+++ b/frontend/src/components/tools/automate/ToolSelector.tsx
@@ -1,4 +1,4 @@
-import { useState, useMemo, useCallback, useRef, useEffect } from 'react';
+import React, { useState, useMemo, useCallback, useRef, useEffect } from 'react';
 import { useTranslation } from 'react-i18next';
 import { Stack, Text, ScrollArea } from '@mantine/core';
 import { ToolRegistryEntry } from '../../../data/toolsTaxonomy';
@@ -82,7 +82,7 @@ export default function ToolSelector({
 
     // Find the "all" section which contains all tools without duplicates
     const allSection = sections.find(s => (s as any).key === 'all');
-    return allSection?.subcategories || [];
+    return allSection?.subcategories ?? [];
   }, [isSearching, searchGroups, sections, baseFilteredTools]);
 
   const handleToolSelect = useCallback((toolKey: string) => {
@@ -138,7 +138,7 @@ export default function ToolSelector({
     if (selectedValue && toolRegistry[selectedValue]) {
       return toolRegistry[selectedValue].name;
     }
-    return placeholder || t('automate.creation.tools.add', 'Add a tool...');
+    return placeholder ?? t('automate.creation.tools.add', 'Add a tool...');
   };
 
   return (
diff --git a/frontend/src/components/tools/certSign/CertificateFilesSettings.tsx b/frontend/src/components/tools/certSign/CertificateFilesSettings.tsx
index a11ba5b72..06610e5b4 100644
--- a/frontend/src/components/tools/certSign/CertificateFilesSettings.tsx
+++ b/frontend/src/components/tools/certSign/CertificateFilesSettings.tsx
@@ -1,3 +1,4 @@
+import React from "react";
 import { Stack, Text, TextInput } from "@mantine/core";
 import { useTranslation } from "react-i18next";
 import { CertSignParameters } from "../../../hooks/tools/certSign/useCertSignParameters";
@@ -19,7 +20,7 @@ const CertificateFilesSettings = ({ parameters, onParameterChange, disabled = fa
         <Stack gap="sm">
           <FileUploadButton
             file={parameters.privateKeyFile}
-            onChange={(file) => onParameterChange('privateKeyFile', file || undefined)}
+            onChange={(file) => onParameterChange('privateKeyFile', file ?? undefined)}
             accept=".pem,.der,.key"
             disabled={disabled}
             placeholder={t('certSign.choosePrivateKey', 'Choose Private Key File')}
@@ -27,7 +28,7 @@ const CertificateFilesSettings = ({ parameters, onParameterChange, disabled = fa
           {parameters.privateKeyFile && (
             <FileUploadButton
               file={parameters.certFile}
-              onChange={(file) => onParameterChange('certFile', file || undefined)}
+              onChange={(file) => onParameterChange('certFile', file ?? undefined)}
               accept=".pem,.der,.crt,.cer"
               disabled={disabled}
               placeholder={t('certSign.chooseCertificate', 'Choose Certificate File')}
@@ -39,7 +40,7 @@ const CertificateFilesSettings = ({ parameters, onParameterChange, disabled = fa
       {parameters.certType === 'PKCS12' && (
         <FileUploadButton
           file={parameters.p12File}
-          onChange={(file) => onParameterChange('p12File', file || undefined)}
+          onChange={(file) => onParameterChange('p12File', file ?? undefined)}
           accept=".p12"
           disabled={disabled}
           placeholder={t('certSign.chooseP12File', 'Choose PKCS12 File')}
@@ -49,7 +50,7 @@ const CertificateFilesSettings = ({ parameters, onParameterChange, disabled = fa
       {parameters.certType === 'PFX' && (
         <FileUploadButton
           file={parameters.p12File}
-          onChange={(file) => onParameterChange('p12File', file || undefined)}
+          onChange={(file) => onParameterChange('p12File', file ?? undefined)}
           accept=".pfx"
           disabled={disabled}
           placeholder={t('certSign.choosePfxFile', 'Choose PFX File')}
@@ -59,7 +60,7 @@ const CertificateFilesSettings = ({ parameters, onParameterChange, disabled = fa
       {parameters.certType === 'JKS' && (
         <FileUploadButton
           file={parameters.jksFile}
-          onChange={(file) => onParameterChange('jksFile', file || undefined)}
+          onChange={(file) => onParameterChange('jksFile', file ?? undefined)}
           accept=".jks,.keystore"
           disabled={disabled}
           placeholder={t('certSign.chooseJksFile', 'Choose JKS File')}
@@ -74,9 +75,9 @@ const CertificateFilesSettings = ({ parameters, onParameterChange, disabled = fa
 
       {/* Password - only show when files are uploaded */}
       {parameters.certType && (
-        (parameters.certType === 'PEM' && parameters.privateKeyFile && parameters.certFile) ||
-        (parameters.certType === 'PKCS12' && parameters.p12File) ||
-        (parameters.certType === 'PFX' && parameters.p12File) ||
+        (parameters.certType === 'PEM' && parameters.privateKeyFile && parameters.certFile) ??
+        (parameters.certType === 'PKCS12' && parameters.p12File) ??
+        (parameters.certType === 'PFX' && parameters.p12File) ??
         (parameters.certType === 'JKS' && parameters.jksFile)
       ) && (
         <TextInput
@@ -92,4 +93,4 @@ const CertificateFilesSettings = ({ parameters, onParameterChange, disabled = fa
   );
 };
 
-export default CertificateFilesSettings;
\ No newline at end of file
+export default CertificateFilesSettings;
diff --git a/frontend/src/components/tools/certSign/CertificateFormatSettings.tsx b/frontend/src/components/tools/certSign/CertificateFormatSettings.tsx
index 6fac53f4d..54498a5b2 100644
--- a/frontend/src/components/tools/certSign/CertificateFormatSettings.tsx
+++ b/frontend/src/components/tools/certSign/CertificateFormatSettings.tsx
@@ -1,3 +1,4 @@
+import React from "react";
 import { Stack, Button } from "@mantine/core";
 import { CertSignParameters } from "../../../hooks/tools/certSign/useCertSignParameters";
 
diff --git a/frontend/src/components/tools/certSign/CertificateTypeSettings.tsx b/frontend/src/components/tools/certSign/CertificateTypeSettings.tsx
index 2d514a161..acc216014 100644
--- a/frontend/src/components/tools/certSign/CertificateTypeSettings.tsx
+++ b/frontend/src/components/tools/certSign/CertificateTypeSettings.tsx
@@ -1,3 +1,4 @@
+import React from "react";
 import { Stack, Button } from "@mantine/core";
 import { CertSignParameters } from "../../../hooks/tools/certSign/useCertSignParameters";
 import { useAppConfig } from "../../../hooks/useAppConfig";
diff --git a/frontend/src/components/tools/certSign/SignatureAppearanceSettings.tsx b/frontend/src/components/tools/certSign/SignatureAppearanceSettings.tsx
index aa99be742..5e382d5f7 100644
--- a/frontend/src/components/tools/certSign/SignatureAppearanceSettings.tsx
+++ b/frontend/src/components/tools/certSign/SignatureAppearanceSettings.tsx
@@ -1,3 +1,4 @@
+import React from "react";
 import { Stack, Text, Button, TextInput, NumberInput } from "@mantine/core";
 import { useTranslation } from "react-i18next";
 import { CertSignParameters } from "../../../hooks/tools/certSign/useCertSignParameters";
diff --git a/frontend/src/components/tools/changeMetadata/ChangeMetadataSingleStep.tsx b/frontend/src/components/tools/changeMetadata/ChangeMetadataSingleStep.tsx
index ef95718e9..3304c2269 100644
--- a/frontend/src/components/tools/changeMetadata/ChangeMetadataSingleStep.tsx
+++ b/frontend/src/components/tools/changeMetadata/ChangeMetadataSingleStep.tsx
@@ -1,3 +1,4 @@
+import React from "react";
 import { Stack, Divider, Text } from "@mantine/core";
 import { useTranslation } from "react-i18next";
 import { ChangeMetadataParameters, createCustomMetadataFunctions } from "../../../hooks/tools/changeMetadata/useChangeMetadataParameters";
diff --git a/frontend/src/components/tools/changeMetadata/steps/AdvancedOptionsStep.tsx b/frontend/src/components/tools/changeMetadata/steps/AdvancedOptionsStep.tsx
index 0edffe21d..27eade4c7 100644
--- a/frontend/src/components/tools/changeMetadata/steps/AdvancedOptionsStep.tsx
+++ b/frontend/src/components/tools/changeMetadata/steps/AdvancedOptionsStep.tsx
@@ -1,3 +1,4 @@
+import React from "react";
 import { Stack, Select, Divider } from "@mantine/core";
 import { useTranslation } from "react-i18next";
 import { ChangeMetadataParameters } from "../../../../hooks/tools/changeMetadata/useChangeMetadataParameters";
diff --git a/frontend/src/components/tools/changeMetadata/steps/CustomMetadataStep.tsx b/frontend/src/components/tools/changeMetadata/steps/CustomMetadataStep.tsx
index beb139e50..6b1385ec2 100644
--- a/frontend/src/components/tools/changeMetadata/steps/CustomMetadataStep.tsx
+++ b/frontend/src/components/tools/changeMetadata/steps/CustomMetadataStep.tsx
@@ -1,3 +1,4 @@
+import React from "react";
 import { Stack, TextInput, Button, Group, Text } from "@mantine/core";
 import { useTranslation } from "react-i18next";
 import { ChangeMetadataParameters } from "../../../../hooks/tools/changeMetadata/useChangeMetadataParameters";
diff --git a/frontend/src/components/tools/changeMetadata/steps/DeleteAllStep.tsx b/frontend/src/components/tools/changeMetadata/steps/DeleteAllStep.tsx
index fbd983a18..d97b0c9dd 100644
--- a/frontend/src/components/tools/changeMetadata/steps/DeleteAllStep.tsx
+++ b/frontend/src/components/tools/changeMetadata/steps/DeleteAllStep.tsx
@@ -1,3 +1,4 @@
+import React from "react";
 import { Checkbox } from "@mantine/core";
 import { useTranslation } from "react-i18next";
 import { ChangeMetadataParameters } from "../../../../hooks/tools/changeMetadata/useChangeMetadataParameters";
diff --git a/frontend/src/components/tools/changeMetadata/steps/DocumentDatesStep.tsx b/frontend/src/components/tools/changeMetadata/steps/DocumentDatesStep.tsx
index e46e7799d..949f54491 100644
--- a/frontend/src/components/tools/changeMetadata/steps/DocumentDatesStep.tsx
+++ b/frontend/src/components/tools/changeMetadata/steps/DocumentDatesStep.tsx
@@ -1,3 +1,4 @@
+import React from "react";
 import { Stack } from "@mantine/core";
 import { DateTimePicker } from "@mantine/dates";
 import { useTranslation } from "react-i18next";
diff --git a/frontend/src/components/tools/changeMetadata/steps/StandardMetadataStep.tsx b/frontend/src/components/tools/changeMetadata/steps/StandardMetadataStep.tsx
index 02b5715cd..741bb63a1 100644
--- a/frontend/src/components/tools/changeMetadata/steps/StandardMetadataStep.tsx
+++ b/frontend/src/components/tools/changeMetadata/steps/StandardMetadataStep.tsx
@@ -1,3 +1,4 @@
+import React from "react";
 import { Stack, TextInput } from "@mantine/core";
 import { useTranslation } from "react-i18next";
 import { ChangeMetadataParameters } from "../../../../hooks/tools/changeMetadata/useChangeMetadataParameters";
diff --git a/frontend/src/components/tools/changePermissions/ChangePermissionsSettings.test.tsx b/frontend/src/components/tools/changePermissions/ChangePermissionsSettings.test.tsx
index 14d0cf1e4..a70f67481 100644
--- a/frontend/src/components/tools/changePermissions/ChangePermissionsSettings.test.tsx
+++ b/frontend/src/components/tools/changePermissions/ChangePermissionsSettings.test.tsx
@@ -1,3 +1,4 @@
+import React from 'react';
 import { describe, expect, test, vi, beforeEach } from 'vitest';
 import { render, screen, fireEvent } from '@testing-library/react';
 import { MantineProvider } from '@mantine/core';
diff --git a/frontend/src/components/tools/changePermissions/ChangePermissionsSettings.tsx b/frontend/src/components/tools/changePermissions/ChangePermissionsSettings.tsx
index 83e132ec6..f6d365e44 100644
--- a/frontend/src/components/tools/changePermissions/ChangePermissionsSettings.tsx
+++ b/frontend/src/components/tools/changePermissions/ChangePermissionsSettings.tsx
@@ -1,3 +1,4 @@
+import React from "react";
 import { Stack, Checkbox } from "@mantine/core";
 import { useTranslation } from "react-i18next";
 import { ChangePermissionsParameters } from "../../../hooks/tools/changePermissions/useChangePermissionsParameters";
diff --git a/frontend/src/components/tools/convert/ConvertToPdfaSettings.tsx b/frontend/src/components/tools/convert/ConvertToPdfaSettings.tsx
index b9a572b8d..e1ca71b74 100644
--- a/frontend/src/components/tools/convert/ConvertToPdfaSettings.tsx
+++ b/frontend/src/components/tools/convert/ConvertToPdfaSettings.tsx
@@ -44,7 +44,7 @@ const ConvertToPdfaSettings = ({
           value={parameters.pdfaOptions.outputFormat}
           onChange={(value) => onParameterChange('pdfaOptions', {
             ...parameters.pdfaOptions,
-            outputFormat: value || 'pdfa-1'
+            outputFormat: value ?? 'pdfa-1'
           })}
           data={pdfaFormatOptions}
           disabled={disabled || isChecking}
diff --git a/frontend/src/components/tools/crop/CropSettings.tsx b/frontend/src/components/tools/crop/CropSettings.tsx
index dafcdeaab..9301bb25a 100644
--- a/frontend/src/components/tools/crop/CropSettings.tsx
+++ b/frontend/src/components/tools/crop/CropSettings.tsx
@@ -1,4 +1,4 @@
-import { useMemo, useState, useEffect } from "react";
+import React, { useMemo, useState, useEffect } from "react";
 import { Stack, Text, Box, Group, NumberInput, ActionIcon, Center, Alert } from "@mantine/core";
 import { useTranslation } from "react-i18next";
 import RestartAltIcon from "@mui/icons-material/RestartAlt";
@@ -48,7 +48,7 @@ const CropSettings = ({ parameters, disabled = false }: CropSettingsProps) => {
         return;
       }
 
-      setThumbnail(selectedStub.thumbnailUrl || null);
+      setThumbnail(selectedStub.thumbnailUrl ?? null);
 
       try {
         // Get PDF dimensions from the actual file
@@ -89,7 +89,7 @@ const CropSettings = ({ parameters, disabled = false }: CropSettingsProps) => {
       }
     };
 
-    loadPDFDimensions();
+    void loadPDFDimensions();
   }, [selectedStub, selectedFile, parameters]);
 
   // Current crop area
diff --git a/frontend/src/components/tools/flatten/FlattenSettings.tsx b/frontend/src/components/tools/flatten/FlattenSettings.tsx
index 8386ad493..7c85ec401 100644
--- a/frontend/src/components/tools/flatten/FlattenSettings.tsx
+++ b/frontend/src/components/tools/flatten/FlattenSettings.tsx
@@ -1,3 +1,4 @@
+import React from "react";
 import { Stack, Text, Checkbox } from "@mantine/core";
 import { useTranslation } from "react-i18next";
 import { FlattenParameters } from "../../../hooks/tools/flatten/useFlattenParameters";
diff --git a/frontend/src/components/tools/merge/MergeFileSorter.test.tsx b/frontend/src/components/tools/merge/MergeFileSorter.test.tsx
index 302777261..b19e1f4f9 100644
--- a/frontend/src/components/tools/merge/MergeFileSorter.test.tsx
+++ b/frontend/src/components/tools/merge/MergeFileSorter.test.tsx
@@ -1,3 +1,4 @@
+import React from 'react';
 import { describe, expect, test, vi, beforeEach } from 'vitest';
 import { render, screen, fireEvent } from '@testing-library/react';
 import { MantineProvider } from '@mantine/core';
diff --git a/frontend/src/components/tools/merge/MergeSettings.test.tsx b/frontend/src/components/tools/merge/MergeSettings.test.tsx
index 7989fa6d0..657d3199a 100644
--- a/frontend/src/components/tools/merge/MergeSettings.test.tsx
+++ b/frontend/src/components/tools/merge/MergeSettings.test.tsx
@@ -1,3 +1,4 @@
+import React from 'react';
 import { describe, expect, test, vi, beforeEach } from 'vitest';
 import { render, screen, fireEvent } from '@testing-library/react';
 import { MantineProvider } from '@mantine/core';
diff --git a/frontend/src/components/tools/ocr/LanguagePicker.tsx b/frontend/src/components/tools/ocr/LanguagePicker.tsx
index 31f0fe301..d94a34613 100644
--- a/frontend/src/components/tools/ocr/LanguagePicker.tsx
+++ b/frontend/src/components/tools/ocr/LanguagePicker.tsx
@@ -75,7 +75,7 @@ const LanguagePicker: React.FC<LanguagePickerProps> = ({
       }
     };
 
-    fetchLanguages();
+    void fetchLanguages();
   }, [languagesEndpoint]);
 
   // Auto-fill OCR language based on browser language when languages are loaded
diff --git a/frontend/src/components/tools/ocr/OCRSettings.tsx b/frontend/src/components/tools/ocr/OCRSettings.tsx
index 959601166..9aff013c3 100644
--- a/frontend/src/components/tools/ocr/OCRSettings.tsx
+++ b/frontend/src/components/tools/ocr/OCRSettings.tsx
@@ -23,7 +23,7 @@ const OCRSettings: React.FC<OCRSettingsProps> = ({
       <Select
         label={t('ocr.settings.ocrMode.label', 'OCR Mode')}
         value={parameters.ocrType}
-        onChange={(value) => onParameterChange('ocrType', value || 'skip-text')}
+        onChange={(value) => onParameterChange('ocrType', value ?? 'skip-text')}
         data={[
           { value: 'skip-text', label: t('ocr.settings.ocrMode.auto', 'Auto (skip text layers)') },
           { value: 'force-ocr', label: t('ocr.settings.ocrMode.force', 'Force (re-OCR all, replace text)') },
diff --git a/frontend/src/components/tools/redact/RedactAdvancedSettings.test.tsx b/frontend/src/components/tools/redact/RedactAdvancedSettings.test.tsx
index 92f359abd..8d314daa5 100644
--- a/frontend/src/components/tools/redact/RedactAdvancedSettings.test.tsx
+++ b/frontend/src/components/tools/redact/RedactAdvancedSettings.test.tsx
@@ -1,3 +1,4 @@
+import React from 'react';
 import { describe, expect, test, vi, beforeEach } from 'vitest';
 import { render, screen, fireEvent } from '@testing-library/react';
 import { MantineProvider } from '@mantine/core';
diff --git a/frontend/src/components/tools/redact/RedactAdvancedSettings.tsx b/frontend/src/components/tools/redact/RedactAdvancedSettings.tsx
index 26a96056b..4df502b4d 100644
--- a/frontend/src/components/tools/redact/RedactAdvancedSettings.tsx
+++ b/frontend/src/components/tools/redact/RedactAdvancedSettings.tsx
@@ -1,3 +1,4 @@
+import React from "react";
 import { Stack, NumberInput, ColorInput, Checkbox } from "@mantine/core";
 import { useTranslation } from "react-i18next";
 import { RedactParameters } from "../../../hooks/tools/redact/useRedactParameters";
diff --git a/frontend/src/components/tools/redact/RedactModeSelector.tsx b/frontend/src/components/tools/redact/RedactModeSelector.tsx
index c073bc520..13acb700a 100644
--- a/frontend/src/components/tools/redact/RedactModeSelector.tsx
+++ b/frontend/src/components/tools/redact/RedactModeSelector.tsx
@@ -1,3 +1,4 @@
+import React from 'react';
 import { useTranslation } from 'react-i18next';
 import { RedactMode } from '../../../hooks/tools/redact/useRedactParameters';
 import ButtonSelector from '../../shared/ButtonSelector';
diff --git a/frontend/src/components/tools/redact/RedactSingleStepSettings.test.tsx b/frontend/src/components/tools/redact/RedactSingleStepSettings.test.tsx
index 2bfe94e06..928454c0a 100644
--- a/frontend/src/components/tools/redact/RedactSingleStepSettings.test.tsx
+++ b/frontend/src/components/tools/redact/RedactSingleStepSettings.test.tsx
@@ -1,3 +1,4 @@
+import React from 'react';
 import { describe, expect, test, vi, beforeEach } from 'vitest';
 import { render, screen, fireEvent } from '@testing-library/react';
 import { MantineProvider } from '@mantine/core';
diff --git a/frontend/src/components/viewer/SearchInterface.tsx b/frontend/src/components/viewer/SearchInterface.tsx
index 71b8f17b9..588084317 100644
--- a/frontend/src/components/viewer/SearchInterface.tsx
+++ b/frontend/src/components/viewer/SearchInterface.tsx
@@ -80,7 +80,7 @@ export function SearchInterface({ visible, onClose }: SearchInterfaceProps) {
 
   const handleKeyDown = (event: React.KeyboardEvent<HTMLInputElement>) => {
     if (event.key === 'Enter') {
-      handleSearch(searchQuery);
+      void handleSearch(searchQuery);
     } else if (event.key === 'Escape') {
       onClose();
     }
diff --git a/frontend/src/components/viewer/ThumbnailSidebar.tsx b/frontend/src/components/viewer/ThumbnailSidebar.tsx
index 5abb472bf..b3848ba02 100644
--- a/frontend/src/components/viewer/ThumbnailSidebar.tsx
+++ b/frontend/src/components/viewer/ThumbnailSidebar.tsx
@@ -65,7 +65,7 @@ export function ThumbnailSidebar({ visible, onToggle: _onToggle }: ThumbnailSide
       }
     };
 
-    generateThumbnails();
+    void generateThumbnails();
   }, [visible, scrollState.totalPages, thumbnailAPI]);
 
   const handlePageClick = (pageIndex: number) => {
diff --git a/frontend/src/contexts/FilesModalContext.tsx b/frontend/src/contexts/FilesModalContext.tsx
index e850fa4dd..da141eebd 100644
--- a/frontend/src/contexts/FilesModalContext.tsx
+++ b/frontend/src/contexts/FilesModalContext.tsx
@@ -43,7 +43,7 @@ export const FilesModalProvider: React.FC<{ children: React.ReactNode }> = ({ ch
       customHandler(files, insertAfterPage);
     } else {
       // Use normal file handling
-      addFiles(files);
+      void addFiles(files);
     }
     closeFilesModal();
   }, [addFiles, closeFilesModal, insertAfterPage, customHandler]);
@@ -59,7 +59,7 @@ export const FilesModalProvider: React.FC<{ children: React.ReactNode }> = ({ ch
             loadedFiles.push(stirlingFile);
           }
         }
-        
+
         if (loadedFiles.length > 0) {
           customHandler(loadedFiles, insertAfterPage);
         }
@@ -69,7 +69,11 @@ export const FilesModalProvider: React.FC<{ children: React.ReactNode }> = ({ ch
     } else {
       // Normal case - use addStirlingFileStubs to preserve metadata
       if (actions.addStirlingFileStubs) {
-        actions.addStirlingFileStubs(stirlingFileStubs, { selectFiles: true });
+        try {
+          await actions.addStirlingFileStubs(stirlingFileStubs, { selectFiles: true });
+        } catch (error) {
+          console.error('Error adding Stirling file stubs:', error);
+        }
       } else {
         console.error('addStirlingFileStubs action not available');
       }
diff --git a/frontend/src/hooks/tools/automate/useSavedAutomations.ts b/frontend/src/hooks/tools/automate/useSavedAutomations.ts
index 8ad7a80b6..86eceacc8 100644
--- a/frontend/src/hooks/tools/automate/useSavedAutomations.ts
+++ b/frontend/src/hooks/tools/automate/useSavedAutomations.ts
@@ -26,7 +26,7 @@ export function useSavedAutomations() {
   }, []);
 
   const refreshAutomations = useCallback(() => {
-    loadSavedAutomations();
+    void loadSavedAutomations();
   }, [loadSavedAutomations]);
 
   const deleteAutomation = useCallback(async (id: string) => {
@@ -80,7 +80,7 @@ export function useSavedAutomations() {
 
   // Load automations on mount
   useEffect(() => {
-    loadSavedAutomations();
+    void loadSavedAutomations();
   }, [loadSavedAutomations]);
 
   return {
diff --git a/frontend/src/hooks/tools/changeMetadata/useMetadataExtraction.ts b/frontend/src/hooks/tools/changeMetadata/useMetadataExtraction.ts
index 423e19d7e..370b1805f 100644
--- a/frontend/src/hooks/tools/changeMetadata/useMetadataExtraction.ts
+++ b/frontend/src/hooks/tools/changeMetadata/useMetadataExtraction.ts
@@ -60,7 +60,7 @@ export const useMetadataExtraction = (params: MetadataExtractionParams) => {
       setIsExtractingMetadata(false);
     };
 
-    extractMetadata();
+    void extractMetadata();
   }, [selectedFiles, hasExtractedMetadata, params]);
 
   return {
diff --git a/frontend/src/hooks/useAppConfig.ts b/frontend/src/hooks/useAppConfig.ts
index cb23cfb60..20fb7d2fd 100644
--- a/frontend/src/hooks/useAppConfig.ts
+++ b/frontend/src/hooks/useAppConfig.ts
@@ -65,7 +65,7 @@ export function useAppConfig(): UseAppConfigReturn {
   };
 
   useEffect(() => {
-    fetchConfig();
+    void fetchConfig();
   }, []);
 
   return {
diff --git a/frontend/src/hooks/useEndpointConfig.ts b/frontend/src/hooks/useEndpointConfig.ts
index 7516826ed..de87cb33f 100644
--- a/frontend/src/hooks/useEndpointConfig.ts
+++ b/frontend/src/hooks/useEndpointConfig.ts
@@ -41,7 +41,7 @@ export function useEndpointEnabled(endpoint: string): {
   };
 
   useEffect(() => {
-    fetchEndpointStatus();
+    void fetchEndpointStatus();
   }, [endpoint]);
 
   return {
@@ -105,7 +105,7 @@ export function useMultipleEndpointsEnabled(endpoints: string[]): {
   };
 
   useEffect(() => {
-    fetchAllEndpointStatuses();
+    void fetchAllEndpointStatuses();
   }, [endpoints.join(',')]); // Re-run when endpoints array changes
 
   return {
diff --git a/frontend/src/hooks/useEnhancedProcessedFiles.ts b/frontend/src/hooks/useEnhancedProcessedFiles.ts
index b29107734..8bd38e959 100644
--- a/frontend/src/hooks/useEnhancedProcessedFiles.ts
+++ b/frontend/src/hooks/useEnhancedProcessedFiles.ts
@@ -104,7 +104,7 @@ export function useEnhancedProcessedFiles(
       }
     };
 
-    processFiles();
+    void processFiles();
   }, [activeFiles]); // Only depend on activeFiles to avoid infinite loops
 
   // Listen for processing completion
diff --git a/frontend/src/hooks/useIndexedDBThumbnail.ts b/frontend/src/hooks/useIndexedDBThumbnail.ts
index 389ef5f49..8edfa0153 100644
--- a/frontend/src/hooks/useIndexedDBThumbnail.ts
+++ b/frontend/src/hooks/useIndexedDBThumbnail.ts
@@ -2,7 +2,6 @@ import { useState, useEffect } from "react";
 import { StirlingFileStub } from "../types/fileContext";
 import { useIndexedDB } from "../contexts/IndexedDBContext";
 import { generateThumbnailForFile } from "../utils/thumbnailUtils";
-import { FileId } from "../types/fileContext";
 
 
 /**
@@ -75,7 +74,7 @@ export function useIndexedDBThumbnail(file: StirlingFileStub | undefined | null)
       }
     }
 
-    loadThumbnail();
+    void loadThumbnail();
     return () => { cancelled = true; };
   }, [file, file?.thumbnailUrl, file?.id, indexedDB, generating]);
 
diff --git a/frontend/src/hooks/usePdfSignatureDetection.ts b/frontend/src/hooks/usePdfSignatureDetection.ts
index 77b7f79ac..552c1ab3c 100644
--- a/frontend/src/hooks/usePdfSignatureDetection.ts
+++ b/frontend/src/hooks/usePdfSignatureDetection.ts
@@ -58,7 +58,7 @@ export const usePdfSignatureDetection = (files: StirlingFile[]): PdfSignatureDet
       setIsChecking(false);
     };
 
-    checkForDigitalSignatures();
+    void checkForDigitalSignatures();
   }, [files]);
 
   return {
diff --git a/frontend/src/hooks/useProcessedFiles.ts b/frontend/src/hooks/useProcessedFiles.ts
index 7ee36ab9e..00fc066ec 100644
--- a/frontend/src/hooks/useProcessedFiles.ts
+++ b/frontend/src/hooks/useProcessedFiles.ts
@@ -36,7 +36,7 @@ export function useProcessedFiles(activeFiles: File[]): UseProcessedFilesResult
       setProcessedFiles(newProcessedFiles);
     };
 
-    checkProcessing();
+    void checkProcessing();
 
     return unsubscribe;
   }, [activeFiles]);
diff --git a/frontend/src/i18n.ts b/frontend/src/i18n.ts
index f57d4b1e3..d35468d84 100644
--- a/frontend/src/i18n.ts
+++ b/frontend/src/i18n.ts
@@ -52,7 +52,7 @@ export const supportedLanguages = {
 // RTL languages (based on your existing language.direction property)
 export const rtlLanguages = ['ar-AR', 'fa-IR'];
 
-i18n
+void i18n
   .use(Backend)
   .use(LanguageDetector)
   .use(initReactI18next)
diff --git a/frontend/src/i18n/config.ts b/frontend/src/i18n/config.ts
index 2a7e6a431..467196bc6 100644
--- a/frontend/src/i18n/config.ts
+++ b/frontend/src/i18n/config.ts
@@ -2,7 +2,7 @@ import i18n from 'i18next';
 import { initReactI18next } from 'react-i18next';
 import Backend from 'i18next-http-backend';
 
-i18n
+void i18n
   .use(Backend)
   .use(initReactI18next)
   .init({
@@ -29,7 +29,7 @@ i18n
           'convert.singleOrMultiple': 'Output',
           'convert.emailNote': 'Email attachments and embedded images will be included',
           'common.color': 'Color',
-          'common.grayscale': 'Grayscale', 
+          'common.grayscale': 'Grayscale',
           'common.blackWhite': 'Black & White',
           'common.single': 'Single Image',
           'common.multiple': 'Multiple Images',
@@ -45,4 +45,4 @@ i18n
     }
   });
 
-export default i18n;
\ No newline at end of file
+export default i18n;
diff --git a/frontend/src/services/enhancedPDFProcessingService.ts b/frontend/src/services/enhancedPDFProcessingService.ts
index 3795ef78c..ee04a1db3 100644
--- a/frontend/src/services/enhancedPDFProcessingService.ts
+++ b/frontend/src/services/enhancedPDFProcessingService.ts
@@ -70,7 +70,7 @@ export class EnhancedPDFProcessingService {
     };
 
     // Start processing
-    this.startProcessing(file, fileKey, config, analysis.estimatedProcessingTime);
+    await this.startProcessing(file, fileKey, config, analysis.estimatedProcessingTime);
     return null;
   }
 
diff --git a/frontend/src/services/fileProcessingService.ts b/frontend/src/services/fileProcessingService.ts
index 6bd3011e9..4e7206dc8 100644
--- a/frontend/src/services/fileProcessingService.ts
+++ b/frontend/src/services/fileProcessingService.ts
@@ -60,7 +60,7 @@ class FileProcessingService {
     this.processingCache.set(fileId, operation);
 
     // Clean up cache after completion
-    processingPromise.finally(() => {
+    void processingPromise.finally(() => {
       this.processingCache.delete(fileId);
     });
 
diff --git a/frontend/src/services/fileStorage.ts b/frontend/src/services/fileStorage.ts
index 57a611173..13ef040df 100644
--- a/frontend/src/services/fileStorage.ts
+++ b/frontend/src/services/fileStorage.ts
@@ -78,7 +78,7 @@ class FileStorageService {
 
         request.onerror = () => {
           console.error('IndexedDB add error:', request.error);
-          reject(new Error(request.error?.message || 'Unknown error occurred'));
+          reject(new Error(request.error?.message ?? 'Unknown error occurred'));
         };
         request.onsuccess = () => {
           resolve();
@@ -101,7 +101,7 @@ class FileStorageService {
       const store = transaction.objectStore(this.storeName);
       const request = store.get(id);
 
-      request.onerror = () => reject(new Error(request.error?.message || 'Unknown error occurred'));
+      request.onerror = () => reject(new Error(request.error?.message ?? 'Unknown error occurred'));
       request.onsuccess = () => {
         const record = request.result as StoredStirlingFileRecord | undefined;
         if (!record) {
@@ -142,7 +142,7 @@ class FileStorageService {
       const store = transaction.objectStore(this.storeName);
       const request = store.get(id);
 
-      request.onerror = () => reject(new Error(request.error?.message || 'Unknown error occurred'));
+      request.onerror = () => reject(new Error(request.error?.message ?? 'Unknown error occurred'));
       request.onsuccess = () => {
         const record = request.result as StoredStirlingFileRecord | undefined;
         if (!record) {
@@ -184,7 +184,7 @@ class FileStorageService {
       const request = store.openCursor();
       const stubs: StirlingFileStub[] = [];
 
-      request.onerror = () => reject(new Error(request.error?.message || 'Unknown error occurred'));
+      request.onerror = () => reject(new Error(request.error?.message ?? 'Unknown error occurred'));
       request.onsuccess = (event) => {
         const cursor = (event.target as IDBRequest).result;
         if (cursor) {
@@ -227,7 +227,7 @@ class FileStorageService {
       const request = store.openCursor();
       const leafStubs: StirlingFileStub[] = [];
 
-      request.onerror = () => reject(new Error(request.error?.message || 'Unknown error occurred'));
+      request.onerror = () => reject(new Error(request.error?.message ?? 'Unknown error occurred'));
       request.onsuccess = (event) => {
         const cursor = (event.target as IDBRequest).result;
         if (cursor) {
@@ -269,7 +269,7 @@ class FileStorageService {
       const store = transaction.objectStore(this.storeName);
       const request = store.delete(id);
 
-      request.onerror = () => reject(new Error(request.error?.message || 'Unknown error occurred'));
+      request.onerror = () => reject(new Error(request.error?.message ?? 'Unknown error occurred'));
       request.onsuccess = () => resolve();
     });
   }
@@ -326,7 +326,7 @@ class FileStorageService {
       const store = transaction.objectStore(this.storeName);
       const request = store.clear();
 
-      request.onerror = () => reject(new Error(request.error?.message || 'Unknown error occurred'));
+      request.onerror = () => reject(new Error(request.error?.message ?? 'Unknown error occurred'));
       request.onsuccess = () => resolve();
     });
   }
@@ -384,7 +384,7 @@ class FileStorageService {
         const store = transaction.objectStore(this.storeName);
         const request = store.get(id);
 
-        request.onerror = () => reject(new Error(request.error?.message || 'Unknown error occurred'));
+        request.onerror = () => reject(new Error(request.error?.message ?? 'Unknown error occurred'));
         request.onsuccess = () => {
           const record = request.result as StoredStirlingFileRecord | undefined;
           if (record) {
@@ -415,7 +415,7 @@ class FileStorageService {
       const record = await new Promise<StoredStirlingFileRecord | undefined>((resolve, reject) => {
         const request = store.get(fileId);
         request.onsuccess = () => resolve(request.result);
-        request.onerror = () => reject(new Error(request.error?.message || 'Unknown error occurred'));
+        request.onerror = () => reject(new Error(request.error?.message ?? 'Unknown error occurred'));
       });
 
       if (!record) {
@@ -428,7 +428,7 @@ class FileStorageService {
       await new Promise<void>((resolve, reject) => {
         const request = store.put(record);
         request.onsuccess = () => resolve();
-        request.onerror = () => reject(new Error(request.error?.message || 'Unknown error occurred'));
+        request.onerror = () => reject(new Error(request.error?.message ?? 'Unknown error occurred'));
       });
 
       return true;
@@ -451,7 +451,7 @@ class FileStorageService {
       const record = await new Promise<StoredStirlingFileRecord | undefined>((resolve, reject) => {
         const request = store.get(fileId);
         request.onsuccess = () => resolve(request.result);
-        request.onerror = () => reject(new Error(request.error?.message || 'Unknown error occurred'));
+        request.onerror = () => reject(new Error(request.error?.message ?? 'Unknown error occurred'));
       });
 
       if (!record) {
@@ -464,7 +464,7 @@ class FileStorageService {
       await new Promise<void>((resolve, reject) => {
         const request = store.put(record);
         request.onsuccess = () => resolve();
-        request.onerror = () => reject(new Error(request.error?.message || 'Unknown error occurred'));
+        request.onerror = () => reject(new Error(request.error?.message ?? 'Unknown error occurred'));
       });
 
       return true;
diff --git a/frontend/src/services/indexedDBManager.ts b/frontend/src/services/indexedDBManager.ts
index 7bf55905f..17415fdc3 100644
--- a/frontend/src/services/indexedDBManager.ts
+++ b/frontend/src/services/indexedDBManager.ts
@@ -67,7 +67,7 @@ class IndexedDBManager {
 
       request.onerror = () => {
         console.error(`Failed to open ${config.name}:`, request.error);
-        reject(new Error(request.error?.message || 'Unknown error occurred while opening the database'));
+        reject(new Error(request.error?.message ?? 'Unknown error occurred while opening the database'));
       };
 
       request.onsuccess = () => {
@@ -257,7 +257,7 @@ class IndexedDBManager {
     return new Promise((resolve, reject) => {
       const deleteRequest = indexedDB.deleteDatabase(name);
 
-      deleteRequest.onerror = () => reject(new Error(deleteRequest.error?.message || 'Unknown error occurred while deleting the database'));
+      deleteRequest.onerror = () => reject(new Error(deleteRequest.error?.message ?? 'Unknown error occurred while deleting the database'));
       deleteRequest.onsuccess = () => {
         console.log(`Deleted database: ${name}`);
         resolve();
diff --git a/frontend/src/services/pdfProcessingService.ts b/frontend/src/services/pdfProcessingService.ts
index abcd492ac..9abf46142 100644
--- a/frontend/src/services/pdfProcessingService.ts
+++ b/frontend/src/services/pdfProcessingService.ts
@@ -35,7 +35,7 @@ export class PDFProcessingService {
     }
 
     // Start processing
-    this.startProcessing(file, fileKey);
+    void this.startProcessing(file, fileKey);
     return null;
   }
 
diff --git a/frontend/src/services/pdfWorkerManager.ts b/frontend/src/services/pdfWorkerManager.ts
index 13f18d023..db82f6d29 100644
--- a/frontend/src/services/pdfWorkerManager.ts
+++ b/frontend/src/services/pdfWorkerManager.ts
@@ -94,7 +94,7 @@ class PDFWorkerManager {
       // If document creation fails, make sure to clean up the loading task
       if (loadingTask) {
         try {
-          loadingTask.destroy();
+          await loadingTask.destroy();
         } catch {
           // Ignore errors
         }
@@ -109,7 +109,7 @@ class PDFWorkerManager {
   destroyDocument(pdf: PDFDocumentProxy): void {
     if (this.activeDocuments.has(pdf)) {
       try {
-        pdf.destroy();
+        void pdf.destroy();
         this.activeDocuments.delete(pdf);
         this.workerCount = Math.max(0, this.workerCount - 1);
       } catch {
@@ -167,7 +167,7 @@ class PDFWorkerManager {
     // Force destroy all documents
     this.activeDocuments.forEach(pdf => {
       try {
-        pdf.destroy();
+        void pdf.destroy();
       } catch {
         // Ignore errors
       }
diff --git a/frontend/src/tools/AdjustPageScale.tsx b/frontend/src/tools/AdjustPageScale.tsx
index 26159f551..3a00e0002 100644
--- a/frontend/src/tools/AdjustPageScale.tsx
+++ b/frontend/src/tools/AdjustPageScale.tsx
@@ -52,7 +52,7 @@ const AdjustPageScale = (props: BaseToolProps) => {
       title: t("adjustPageScale.title", "Page Scale Results"),
       onFileClick: base.handleThumbnailClick,
       onUndo: () => {
-        base.handleUndo();
+        void base.handleUndo();
       },
     },
   });
diff --git a/frontend/src/tools/Crop.tsx b/frontend/src/tools/Crop.tsx
index d185e3877..dd398619c 100644
--- a/frontend/src/tools/Crop.tsx
+++ b/frontend/src/tools/Crop.tsx
@@ -1,3 +1,4 @@
+import React from "react";
 import { useTranslation } from "react-i18next";
 import { createToolFlow } from "../components/tools/shared/createToolFlow";
 import CropSettings from "../components/tools/crop/CropSettings";
diff --git a/frontend/src/tools/RemovePassword.tsx b/frontend/src/tools/RemovePassword.tsx
index 970eb324b..f7afe9973 100644
--- a/frontend/src/tools/RemovePassword.tsx
+++ b/frontend/src/tools/RemovePassword.tsx
@@ -1,3 +1,4 @@
+import React from "react";
 import { useTranslation } from "react-i18next";
 import { createToolFlow } from "../components/tools/shared/createToolFlow";
 import RemovePasswordSettings from "../components/tools/removePassword/RemovePasswordSettings";
diff --git a/frontend/src/tools/Rotate.tsx b/frontend/src/tools/Rotate.tsx
index 0b45d8d54..40b75f69a 100644
--- a/frontend/src/tools/Rotate.tsx
+++ b/frontend/src/tools/Rotate.tsx
@@ -1,3 +1,4 @@
+import React from "react";
 import { useTranslation } from "react-i18next";
 import { createToolFlow } from "../components/tools/shared/createToolFlow";
 import RotateSettings from "../components/tools/rotate/RotateSettings";