chore: enforce explicit return types

eslint.config.js

@@ -30,9 +30,18 @@ export default [
     ignores: ['build/', '.svelte-kit/', '.vercel', 'dist/', 'playwright-report/', 'test-results/'],
   },
   {
+    files: ['**/*.{ts,svelte}'],
     rules: {
       '@typescript-eslint/no-explicit-any': 'off',
       '@typescript-eslint/no-var-requires': 'off',
+      '@typescript-eslint/explicit-function-return-type': [
+        'error',
+        {
+          allowExpressions: true,
+          allowTypedFunctionExpressions: true,
+          allowHigherOrderFunctions: true,
+        },
+      ],
       '@typescript-eslint/no-unused-vars': [
         'error',
         {

src/lib/backend/db/news.ts

@@ -67,7 +67,7 @@ export async function searchStory(url: string, options?: SearchStoryOptions): Pr
   }
 }
 
-function buildQuery({ textFilter, dateFilter, sources }: SearchRequestParameters) {
+function buildQuery({ textFilter, dateFilter, sources }: SearchRequestParameters): any {
   const textFilters = textFilter
     ?.split(/\s+/)
     .filter((text) => !!text)

src/lib/components/news/News.svelte

@@ -45,7 +45,7 @@
     clearTimeout(checkUpdatesTimeout);
   });
 
-  async function fetchNews(searchRequestParameters: SearchRequestParameters) {
+  async function fetchNews(searchRequestParameters: SearchRequestParameters): Promise<void> {
     await news.taskWithLoading(async () => {
       const foundNews = await searchNews(searchRequestParameters);
       if (!foundNews?.prevKey) {
@@ -60,7 +60,7 @@
     setCheckUpdatesTimeout(true);
   }
 
-  async function fetchNewNews() {
+  async function fetchNewNews(): Promise<void> {
     await news.taskWithLoading(async () => {
       const currSearchRequestParameters = get(searchRequestParameters);
       const prevKey = get(news).prevKey;
@@ -74,7 +74,7 @@
     setCheckUpdatesTimeout(true);
   }
 
-  async function fetchMoreNews() {
+  async function fetchMoreNews(): Promise<void> {
     await news.taskWithLoading(async () => {
       const currSearchRequestParameters = get(searchRequestParameters);
       const nextKey = get(news).nextKey;
@@ -86,7 +86,7 @@
     });
   }
 
-  async function fetchNewsUpdates() {
+  async function fetchNewsUpdates(): Promise<void> {
     const currSearchRequestParameters = get(searchRequestParameters);
     const prevKey = get(news).prevKey;
     if (!prevKey) {
@@ -119,7 +119,7 @@
     cancelCheckNewsUpdates();
   }
 
-  function setCheckUpdatesTimeout(initial: boolean) {
+  function setCheckUpdatesTimeout(initial: boolean): void {
     if (!$settings.checkNewsUpdates) {
       return;
     }

src/lib/components/news/filter/BookmarkActions.svelte

@@ -20,19 +20,19 @@
     unsubscribeAll(subscriptions);
   });
 
-  function handleStartSearch() {
+  function handleStartSearch(): void {
     textFilterInputRef?.focus();
   }
 
-  function handleTextFilterChange(textFilter?: string) {
+  function handleTextFilterChange(textFilter?: string): void {
     bookmarks.setTextFilter(textFilter ?? '');
   }
 
-  function handleDeleteAllBookmarks() {
+  function handleDeleteAllBookmarks(): void {
     bookmarks.removeAll();
   }
 
-  function handleDeleteAllViewedBookmarks() {
+  function handleDeleteAllViewedBookmarks(): void {
     bookmarks.removeAllViewed();
   }
 </script>

src/lib/components/news/filter/BookmarkDeletePopover.svelte

@@ -23,11 +23,11 @@
     transition
   `;
 
-  function handleRemoveAllBookmarksButtonClick() {
+  function handleRemoveAllBookmarksButtonClick(): void {
     onRemoveAllBookmarks?.();
   }
 
-  function handleRemoveAllViewedBookmarksButtonClick() {
+  function handleRemoveAllViewedBookmarksButtonClick(): void {
     onRemoveAllViewedBookmarks?.();
   }
 </script>

src/lib/components/news/filter/NewsFilter.svelte

@@ -21,19 +21,19 @@
     unsubscribeAll(subscriptions);
   });
 
-  function handleStartSearch() {
+  function handleStartSearch(): void {
     textFilterInputRef?.focus();
   }
 
-  function handleTextFilterChange(textFilter?: string) {
+  function handleTextFilterChange(textFilter?: string): void {
     searchFilter.setTextFilter(textFilter);
   }
 
-  function handleDateFilterFromChange(from?: string) {
+  function handleDateFilterFromChange(from?: string): void {
     searchFilter.setFrom(from);
   }
 
-  function handleDateFilterToChange(to?: string) {
+  function handleDateFilterToChange(to?: string): void {
     searchFilter.setTo(to);
   }
 </script>

src/lib/components/news/filter/NewsFilterPopover.svelte

@@ -45,35 +45,35 @@
   const menuActionsClass = `grid grid-cols-2 gap-x-3 gap-y-2 w-full`;
   const menuButtonClass = `!w-full`;
 
-  function handleFromChange(from?: DateTime) {
+  function handleFromChange(from?: DateTime): void {
     onFromChange?.(from?.startOf('day').toISO() ?? undefined);
   }
 
-  function handleToChange(to?: DateTime) {
+  function handleToChange(to?: DateTime): void {
     onToChange?.(to?.endOf('day').toISO() ?? undefined);
   }
 
-  function handleApplyClick() {
+  function handleApplyClick(): void {
     onApply?.();
   }
 
-  function handleResetClick() {
+  function handleResetClick(): void {
     onReset?.();
   }
 
-  function handleSelectTodayClick() {
+  function handleSelectTodayClick(): void {
     onSelectToday?.();
   }
 
-  function handleSelectLastWeekClick() {
+  function handleSelectLastWeekClick(): void {
     onSelectLastWeek?.();
   }
 
-  function handleSelectLastMonthClick() {
+  function handleSelectLastMonthClick(): void {
     onSelectLastMonth?.();
   }
 
-  function handleSelectLastYearClick() {
+  function handleSelectLastYearClick(): void {
     onSelectLastYear?.();
   }
 </script>

src/lib/components/news/story/header/options/BookmarkButton.svelte

@@ -15,7 +15,7 @@
 
   let { story, class: clazz, onClose }: Props = $props();
 
-  function handleAddToBookmarksClick() {
+  function handleAddToBookmarksClick(): void {
     bookmarks.add(story);
     notifications.notify('Lesezeichen hinzugefügt', 'Der Artikel wurde zu deinen Lesezeichen hinzugefügt.', {
       forceAppNotification: true,
@@ -24,7 +24,7 @@
     onClose?.();
   }
 
-  function handleRemoveFromBookmarksClick() {
+  function handleRemoveFromBookmarksClick(): void {
     bookmarks.remove(story);
     notifications.notify('Lesezeichen entfernt', 'Der Artikel wurde von deinen Lesezeichen entfernt.', {
       forceAppNotification: true,

src/lib/components/news/story/header/options/OpenArticleButton.svelte

@@ -12,7 +12,7 @@
 
   let { story, class: clazz, onClose }: Props = $props();
 
-  function handleOpenArticleClick() {
+  function handleOpenArticleClick(): void {
     onClose?.();
   }
 </script>

src/lib/components/news/story/header/options/OpenSupportButton.svelte

@@ -10,7 +10,7 @@
 
   let { class: clazz, onClose }: Props = $props();
 
-  function handleOpenSupportClick() {
+  function handleOpenSupportClick(): void {
     onClose?.();
   }
 </script>

src/lib/components/news/story/header/options/ShareButton.svelte

@@ -27,7 +27,7 @@
     return !!navigator.clipboard?.writeText;
   }
 
-  async function handleShareArticleClick() {
+  async function handleShareArticleClick(): Promise<void> {
     try {
       await navigator.share(shareData);
     } catch (error) {
@@ -38,7 +38,7 @@
     onClose?.();
   }
 
-  async function handleCopyToClipboardClick() {
+  async function handleCopyToClipboardClick(): Promise<void> {
     const text = new Blob([story.url], { type: 'text/plain' });
     const html = new Blob(
       [`<a id="${story.id}" data-timestamp="${story.timestamp}" href="${story.url}">${story.title}</a>`],

src/lib/components/settings/appearance/Appearance.svelte

@@ -7,7 +7,7 @@
 
   let colorScheme: ColorScheme = $state($styles.colorScheme);
 
-  function handleColorSchemeRadioChange() {
+  function handleColorSchemeRadioChange(): void {
     if (colorScheme) {
       styles.setColorScheme(colorScheme);
     }

src/lib/components/settings/developer/Developer.svelte

@@ -45,12 +45,12 @@
     return estimate.usage;
   }
 
-  function handleResetIndexedDbButtonClick() {
+  function handleResetIndexedDbButtonClick(): void {
     indexedDB.deleteDatabase(BOOKMARKS_STORE_NAME);
     location.reload();
   }
 
-  function handleResetLocalStorageButtonClick() {
+  function handleResetLocalStorageButtonClick(): void {
     localStorage.clear();
     location.reload();
   }

src/lib/components/shared/app/EnableAnalytics.svelte

@@ -4,7 +4,7 @@
   import { browser } from '$app/environment';
   import { PUBLIC_ENABLE_ANALYTICS } from '$env/static/public';
 
-  function isAnalyticsEnabled() {
+  function isAnalyticsEnabled(): boolean {
     return PUBLIC_ENABLE_ANALYTICS === 'true';
   }
 

src/lib/components/shared/app/EnableDarkMode.svelte

@@ -21,7 +21,7 @@
     }
   });
 
-  function applyColorScheme(colorScheme: ColorScheme, prefersDarkColorScheme?: boolean) {
+  function applyColorScheme(colorScheme: ColorScheme, prefersDarkColorScheme?: boolean): void {
     if (colorScheme === 'system') {
       if (prefersDarkColorScheme ?? getPrefersDarkColorSchemeQuery()?.matches) {
         setDarkClass();
@@ -37,22 +37,22 @@
     }
   }
 
-  function changeColorScheme({ matches: prefersDarkColorScheme }: { matches: boolean }) {
+  function changeColorScheme({ matches: prefersDarkColorScheme }: { matches: boolean }): void {
     const colorScheme = $styles.colorScheme;
     if (colorScheme === 'system') {
       applyColorScheme(colorScheme, prefersDarkColorScheme);
     }
   }
 
-  function getPrefersDarkColorSchemeQuery() {
+  function getPrefersDarkColorSchemeQuery(): MediaQueryList {
     return window.matchMedia('(prefers-color-scheme: dark)');
   }
 
-  function setLightClass() {
+  function setLightClass(): void {
     document.documentElement.classList.remove('dark');
   }
 
-  function setDarkClass() {
+  function setDarkClass(): void {
     document.documentElement.classList.add('dark');
   }
 </script>

src/lib/components/shared/app/EnableGlobalKeybindings.svelte

@@ -1,14 +1,14 @@
 <script lang="ts">
   import { startSearch } from '$lib/stores/newsEvents';
 
-  function handleKeydown(event: KeyboardEvent) {
+  function handleKeydown(event: KeyboardEvent): void {
     if (isSearchShortcut(event)) {
       event.preventDefault();
       startSearch.notify();
     }
   }
 
-  function isSearchShortcut(event: KeyboardEvent) {
+  function isSearchShortcut(event: KeyboardEvent): boolean {
     const { key, metaKey, ctrlKey } = event;
     return (metaKey || ctrlKey) && ['f', 'k'].includes(key);
   }

src/lib/components/shared/app/EnableNetworkNotifications.svelte

@@ -9,7 +9,7 @@
     warnIfOffline($online);
   });
 
-  function warnIfOffline(online: boolean) {
+  function warnIfOffline(online: boolean): void {
     if (!online) {
       notifications.notify(
         'Verbindung unterbrochen',

src/lib/components/shared/content/AudioPlayer.svelte

@@ -36,11 +36,11 @@
   const metadataClass = ['flex flex-wrap items-center gap-x-1 text-sm text-gray-600 dark:text-gray-300'];
   const controlsClass = ['flex justify-center gap-2'];
 
-  function handleToggleMinimized() {
+  function handleToggleMinimized(): void {
     minimized = !minimized;
   }
 
-  function handleClose() {
+  function handleClose(): void {
     audioStore.end();
     minimized = false;
   }

src/lib/components/shared/content/Header.svelte

@@ -22,11 +22,11 @@
 
   let isNewsPage = $derived($page.url.pathname === '/');
 
-  function handleRefreshButtonClick() {
+  function handleRefreshButtonClick(): void {
     refreshNews.notify();
   }
 
-  async function handleCacheForOfflineUseClick() {
+  async function handleCacheForOfflineUseClick(): Promise<void> {
     notifications.notify('Download gestartet', 'Die neuesten Artikel werden für später geladen.', {
       uniqueCategory: NOTIFICATION_OFFLINE_CACHE_DOWNLOADED,
       replaceInCategory: true,

src/lib/components/shared/content/Popover.svelte

@@ -90,7 +90,7 @@
 
   let popoverButtonClass = $derived(buttonClassFn({ btnType, size, iconOnly, round }));
 
-  export function setOpen(newOpen: boolean) {
+  export function setOpen(newOpen: boolean): void {
     open = newOpen;
   }
 </script>

src/lib/components/shared/controls/DateInput.svelte

@@ -22,11 +22,11 @@
     onchange?.(value);
   });
 
-  export function focus() {
+  export function focus(): void {
     inputRef?.focus();
   }
 
-  function handleKeydown(event: KeyboardEvent) {
+  function handleKeydown(event: KeyboardEvent): void {
     if (event.key === 'Escape') {
       event.preventDefault();
       inputRef?.blur();

src/lib/components/shared/controls/Input.svelte

@@ -33,17 +33,17 @@
     onValueChange?.(value);
   });
 
-  export function focus() {
+  export function focus(): void {
     inputRef?.focus();
   }
 
-  function handleClearButtonClick() {
+  function handleClearButtonClick(): void {
     value = '';
     onclear?.();
     inputRef?.focus();
   }
 
-  function handleKeydown(event: KeyboardEvent) {
+  function handleKeydown(event: KeyboardEvent): void {
     if (event.key === 'Escape') {
       event.preventDefault();
       inputRef?.blur();