From 599b70cd2390d08ce26ee44174b3f39c6587110c Mon Sep 17 00:00:00 2001
From: Armand Philippot <git@armandphilippot.com>
Date: Mon, 13 Nov 2023 12:37:50 +0100
Subject: refactor(hooks): rewrite usePagination hook

* replace `isLoadingInitialData` with `isLoading` & `isRefreshing`
* rename `fallbackData` prop to `fallback`
* replace `setSize` return with a `loadMore` callback
* add tests
---
 src/utils/hooks/use-pagination/use-pagination.ts | 136 +++++++++++++++++++++++
 1 file changed, 136 insertions(+)
 create mode 100644 src/utils/hooks/use-pagination/use-pagination.ts

(limited to 'src/utils/hooks/use-pagination/use-pagination.ts')

diff --git a/src/utils/hooks/use-pagination/use-pagination.ts b/src/utils/hooks/use-pagination/use-pagination.ts
new file mode 100644
index 0000000..4df521b
--- /dev/null
+++ b/src/utils/hooks/use-pagination/use-pagination.ts
@@ -0,0 +1,136 @@
+import { useCallback } from 'react';
+import useSWRInfinite, { type SWRInfiniteKeyLoader } from 'swr/infinite';
+import type {
+  EdgesResponse,
+  GraphQLEdgesInput,
+  Maybe,
+  Nullable,
+  Search,
+} from '../../../types';
+
+export type UsePaginationConfig<T> = {
+  /**
+   * The initial data.
+   */
+  fallback?: EdgesResponse<T>[];
+  /**
+   * A function to fetch more data.
+   */
+  fetcher: (props: GraphQLEdgesInput & Search) => Promise<EdgesResponse<T>>;
+  /**
+   * The number of results per page.
+   */
+  perPage: number;
+  /**
+   * An optional search string.
+   */
+  searchQuery?: string;
+};
+
+export type UsePaginationReturn<T> = {
+  /**
+   * The data from the API.
+   */
+  data: Maybe<EdgesResponse<T>[]>;
+  /**
+   * An error thrown by fetcher.
+   */
+  error: unknown;
+  /**
+   * Determine if there's more data to fetch.
+   */
+  hasNextPage: Maybe<boolean>;
+  /**
+   * Determine if there is some data.
+   */
+  isEmpty: boolean;
+  /**
+   * Determine if there is some errors.
+   */
+  isError: boolean;
+  /**
+   * Determine if there is an ongoing request and no loaded data.
+   */
+  isLoading: boolean;
+  /**
+   * Determine if more data is currently loading.
+   */
+  isLoadingMore: boolean;
+  /**
+   * Determine if the data is refreshing.
+   */
+  isRefreshing: boolean;
+  /**
+   * Determine if there's a request or revalidation loading.
+   */
+  isValidating: boolean;
+  /**
+   * A callback function to load more data.
+   */
+  loadMore: () => Promise<void>;
+  /**
+   * Determine the number of pages that will be fetched and returned.
+   */
+  size: number;
+};
+
+/**
+ * Handle data fetching with pagination.
+ *
+ * This hook is a wrapper of `useSWRInfinite` hook.
+ *
+ * @param {UsePaginationConfig<T>} props - The pagination configuration.
+ * @returns {UsePaginationReturn} An object with pagination data and helpers.
+ */
+export const usePagination = <T>({
+  fallback,
+  fetcher,
+  perPage,
+  searchQuery,
+}: UsePaginationConfig<T>): UsePaginationReturn<T> => {
+  const getKey: SWRInfiniteKeyLoader<EdgesResponse<T>> = useCallback(
+    (pageIndex, previousPageData): Nullable<GraphQLEdgesInput & Search> => {
+      if (previousPageData && !previousPageData.edges.length) return null;
+
+      return {
+        first: perPage,
+        after:
+          pageIndex === 0 ? undefined : previousPageData?.pageInfo.endCursor,
+        search: searchQuery,
+      };
+    },
+    [perPage, searchQuery]
+  );
+
+  const { data, error, isLoading, isValidating, setSize, size } =
+    useSWRInfinite(getKey, fetcher, { fallbackData: fallback });
+
+  const loadMore = useCallback(async () => {
+    await setSize((prevSize) => prevSize + 1);
+  }, [setSize]);
+
+  const hasNextPage =
+    data && data.length > 0 && data[data.length - 1].pageInfo.hasNextPage;
+
+  const isLoadingMore = data
+    ? isLoading || (size > 0 && typeof data[size - 1] === 'undefined')
+    : false;
+
+  const isEmpty = data?.[0]?.edges.length === 0;
+
+  const isRefreshing = data ? isValidating && data.length === size : false;
+
+  return {
+    data,
+    error,
+    hasNextPage,
+    isEmpty,
+    isError: !!error,
+    isLoading,
+    isLoadingMore,
+    isRefreshing,
+    isValidating,
+    loadMore,
+    size,
+  };
+};
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