Extract duplicate by title and alternative title logic into function

src/modules/library/screens/LibraryDuplicates.tsx

@@ -51,23 +51,20 @@ const findDuplicatesByTitle = <Manga extends Pick<MangaType, 'title'>>(
 };
 
 type TMangaDuplicate = Pick<MangaType, 'id' | 'title' | 'description'>;
-const findDuplicatesByTitleAndAlternativeTitles = <Manga extends TMangaDuplicate>(
-    libraryMangas: Manga[],
-): Record<string, Manga[]> => {
-    const titleToMangas: Record<string, Set<Manga>> = {};
-    const titleToAlternativeTitleMatches: Record<string, Set<Manga>> = {};
 
-    libraryMangas.forEach((mangaToCheck) => {
+const findDuplicatesByTitleAndAlternativeTitlesSingleManga = <Manga extends TMangaDuplicate>(
-        const titleToCheck = enhancedCleanup(mangaToCheck.title);
+    manga: Manga,
+    mangas: Manga[],
+): { byTitle: Manga[]; byAlternativeTitle: Manga[] } => {
+    const titleToCheck = enhancedCleanup(manga.title);
 
-        titleToMangas[titleToCheck] ??= new Set();
+    const result: ReturnType<typeof findDuplicatesByTitleAndAlternativeTitlesSingleManga<Manga>> = {
-        titleToMangas[titleToCheck].add(mangaToCheck);
+        byTitle: [manga],
+        byAlternativeTitle: [manga],
+    };
 
-        titleToAlternativeTitleMatches[titleToCheck] ??= new Set();
+    mangas.forEach((libraryManga) => {
-        titleToAlternativeTitleMatches[titleToCheck].add(mangaToCheck);
+        const isDifferentManga = manga.id !== libraryManga.id;
-
-        libraryMangas.forEach((libraryManga) => {
-            const isDifferentManga = mangaToCheck.id !== libraryManga.id;
         if (!isDifferentManga) {
             return;
         }
@@ -81,20 +78,46 @@ const findDuplicatesByTitleAndAlternativeTitles = <Manga extends TMangaDuplicate
         }
 
         if (doesTitleMatch) {
-                titleToMangas[titleToCheck].add(libraryManga);
+            result.byTitle.push(libraryManga);
         }
 
         if (doesAlternativeTitleMatch) {
-                titleToAlternativeTitleMatches[titleToCheck].add(libraryManga);
+            result.byAlternativeTitle.push(libraryManga);
         }
     });
+
+    return result;
+};
+
+const findDuplicatesByTitleAndAlternativeTitles = <Manga extends TMangaDuplicate>(
+    libraryMangas: Manga[],
+): Record<string, Manga[]> => {
+    const titleToMangas: Record<string, Manga[]> = {};
+    const titleToAlternativeTitleMatches: Record<string, Manga[]> = {};
+
+    libraryMangas.forEach((mangaToCheck) => {
+        const titleToCheck = enhancedCleanup(mangaToCheck.title);
+
+        titleToMangas[titleToCheck] ??= [];
+        titleToAlternativeTitleMatches[titleToCheck] ??= [];
+
+        const { byTitle, byAlternativeTitle } = findDuplicatesByTitleAndAlternativeTitlesSingleManga(
+            mangaToCheck,
+            libraryMangas,
+        );
+
+        titleToMangas[titleToCheck].push(...byTitle);
+        titleToAlternativeTitleMatches[titleToCheck].push(...byAlternativeTitle);
     });
 
     const titleToDuplicatesEntries = Object.entries(titleToMangas)
         .map(([title, titleMatches]) => {
-            const originalTitle = [...titleMatches][0].title;
+            const uniqueTitleMatches = new Set(titleMatches);
+            const uniqueAlternativeTitleMatches = new Set(titleToAlternativeTitleMatches[title] ?? []);
 
-            const combinedDuplicates = [...titleMatches, ...(titleToAlternativeTitleMatches[title] ?? [])];
+            const originalTitle = [...uniqueTitleMatches][0].title;
+
+            const combinedDuplicates = [...uniqueTitleMatches, ...uniqueAlternativeTitleMatches];
             const duplicates = [...new Set([...combinedDuplicates])];
 
             const noDuplicatesFound = duplicates.length === 1;