Begin work on infinite beer scroll

src/hooks/useGetBeerPosts.ts

@@ -0,0 +1,56 @@
+import beerPostQueryResult from '@/services/BeerPost/schema/BeerPostQueryResult';
+import APIResponseValidationSchema from '@/validation/APIResponseValidationSchema';
+import useSWRInfinite from 'swr/infinite';
+import { z } from 'zod';
+
+const useGetBeerPosts = ({ pageSize }: { pageSize: number }) => {
+  const fetcher = async (url: string) => {
+    const response = await fetch(url);
+    if (!response.ok) {
+      throw new Error(response.statusText);
+    }
+
+    const json = await response.json();
+    const count = response.headers.get('X-Total-Count');
+
+    const parsed = APIResponseValidationSchema.safeParse(json);
+    if (!parsed.success) {
+      throw new Error('API response validation failed');
+    }
+
+    const parsedPayload = z.array(beerPostQueryResult).safeParse(parsed.data.payload);
+    if (!parsedPayload.success) {
+      throw new Error('API response validation failed');
+    }
+
+    const pageCount = Math.ceil(parseInt(count as string, 10) / pageSize);
+    return {
+      beerPosts: parsedPayload.data,
+      pageCount,
+    };
+  };
+
+  const { data, error, isLoading, setSize, size } = useSWRInfinite(
+    (index) => `/api/beers?pageNum=${index + 1}&pageSize=${pageSize}`,
+    fetcher,
+  );
+
+  const beerPosts = data?.flatMap((d) => d.beerPosts) ?? [];
+  const pageCount = data?.[0].pageCount ?? 0;
+  const isLoadingMore =
+    isLoading || (size > 0 && data && typeof data[size - 1] === 'undefined');
+  const isAtEnd = !(size < data?.[0].pageCount!);
+
+  return {
+    beerPosts,
+    pageCount,
+    size,
+    setSize,
+    isLoading,
+    isLoadingMore,
+    isAtEnd,
+    error: error as unknown,
+  };
+};
+
+export default useGetBeerPosts;