Enable stricter Typescript options (#30435)

app/javascript/mastodon/components/animated_number.tsx

@@ -48,8 +48,9 @@ export const AnimatedNumber: React.FC<Props> = ({ value }) => {
             <span
               key={key}
               style={{
-                position: direction * style.y > 0 ? 'absolute' : 'static',
-                transform: `translateY(${style.y * 100}%)`,
+                position:
+                  direction * (style.y ?? 0) > 0 ? 'absolute' : 'static',
+                transform: `translateY(${(style.y ?? 0) * 100}%)`,
               }}
             >
               <ShortNumber value={data as number} />

app/javascript/mastodon/components/hashtag_bar.tsx

@@ -52,7 +52,10 @@ function uniqueHashtagsWithCaseHandling(hashtags: string[]) {
   );
 
   return Object.values(groups).map((tags) => {
-    if (tags.length === 1) return tags[0];
+    // eslint-disable-next-line @typescript-eslint/no-non-null-assertion -- we know that the array has at least one element
+    const firstTag = tags[0]!;
+
+    if (tags.length === 1) return firstTag;
 
     // The best match is the one where we have the less difference between upper and lower case letter count
     const best = minBy(tags, (tag) => {
@@ -66,7 +69,7 @@ function uniqueHashtagsWithCaseHandling(hashtags: string[]) {
       return Math.abs(lowerCase - upperCase);
     });
 
-    return best ?? tags[0];
+    return best ?? firstTag;
   });
 }
 

app/javascript/mastodon/components/short_number.tsx

@@ -48,7 +48,7 @@ const ShortNumberCounter: React.FC<ShortNumberCounterProps> = ({ value }) => {
 
   const count = (
     <FormattedNumber
-      value={rawNumber}
+      value={rawNumber ?? 0}
       maximumFractionDigits={maxFractionDigits}
     />
   );

app/javascript/mastodon/features/emoji/emoji_mart_data_light.ts

@@ -29,7 +29,10 @@ const emojis: Emojis = {};
 
 // decompress
 Object.keys(shortCodesToEmojiData).forEach((shortCode) => {
-  const [_filenameData, searchData] = shortCodesToEmojiData[shortCode];
+  const emojiData = shortCodesToEmojiData[shortCode];
+  if (!emojiData) return;
+
+  const [_filenameData, searchData] = emojiData;
   const [native, short_names, search, unified] = searchData;
 
   emojis[shortCode] = {

app/javascript/mastodon/features/emoji/emoji_unicode_mapping_light.ts

@@ -46,7 +46,10 @@ function processEmojiMapData(
 Object.keys(shortCodesToEmojiData).forEach(
   (shortCode: ShortCodesToEmojiDataKey) => {
     if (shortCode === undefined) return;
-    const [filenameData, _searchData] = shortCodesToEmojiData[shortCode];
+
+    const emojiData = shortCodesToEmojiData[shortCode];
+    if (!emojiData) return;
+    const [filenameData, _searchData] = emojiData;
     filenameData.forEach((emojiMapData) => {
       processEmojiMapData(emojiMapData, shortCode);
     });

app/javascript/mastodon/store/middlewares/sounds.ts

@@ -74,8 +74,9 @@ export const soundsMiddleware = (): Middleware<
     if (isActionWithMetaSound(action)) {
       const sound = action.meta.sound;
 
-      if (sound && Object.hasOwn(soundCache, sound)) {
-        play(soundCache[sound]);
+      if (sound) {
+        const s = soundCache[sound];
+        if (s) play(s);
       }
     }