test(services): add tests for posts fetchers

2 files changed, 74 insertions, 24 deletions

diff --git a/src/utils/hooks/use-posts-list/use-posts-list.test.ts b/src/utils/hooks/use-posts-list/use-posts-list.test.ts
deleted file mode 100644
index ff69de2..0000000
--- a/src/utils/hooks/use-posts-list/use-posts-list.test.ts
+++ /dev/null
@@ -1,24 +0,0 @@
-import { describe, expect, it } from '@jest/globals';
-import { act, renderHook } from '@testing-library/react';
-import { fetchPostsList } from '../../../services/graphql';
-import { usePostsList } from './use-posts-list';
-
-describe('usePostsList', () => {
-  it('can return the first new result index when loading more posts', async () => {
-    const perPage = 5;
-    const { result } = renderHook(() =>
-      usePostsList({ fetcher: fetchPostsList, perPage })
-    );
-
-    expect.assertions(2);
-
-    expect(result.current.firstNewResultIndex).toBeUndefined();
-
-    await act(async () => {
-      await result.current.loadMore();
-    });
-
-    // Assuming there is more than one page.
-    expect(result.current.firstNewResultIndex).toBe(perPage + 1);
-  });
-});
diff --git a/src/utils/hooks/use-posts-list/use-posts-list.test.tsx b/src/utils/hooks/use-posts-list/use-posts-list.test.tsx
new file mode 100644
index 0000000..f23ddde
--- /dev/null
+++ b/src/utils/hooks/use-posts-list/use-posts-list.test.tsx
@@ -0,0 +1,74 @@
+import {
+  afterEach,
+  beforeEach,
+  describe,
+  expect,
+  it,
+  jest,
+} from '@jest/globals';
+import { act, renderHook } from '@testing-library/react';
+import type { ReactNode } from 'react';
+import { SWRConfig } from 'swr';
+import { fetchPostsList } from '../../../services/graphql';
+import { usePostsList } from './use-posts-list';
+
+const wrapper = ({ children }: { children?: ReactNode }) => {
+  const map = new Map();
+
+  return (
+    <SWRConfig
+      value={{
+        provider: () => map,
+        isOnline() {
+          return true;
+        },
+        isVisible() {
+          return true;
+        },
+        initFocus() {
+          /* nothing */
+        },
+        initReconnect() {
+          /* nothing */
+        },
+      }}
+    >
+      {children}
+    </SWRConfig>
+  );
+};
+
+describe('usePostsList', () => {
+  beforeEach(() => {
+    /* Not sure why it is needed, but without it Jest was complaining with `You
+     * are trying to import a file after the Jest environment has been torn
+     * down`... Maybe because of useSWR? */
+    jest.useFakeTimers({
+      doNotFake: ['queueMicrotask'],
+    });
+  });
+
+  afterEach(() => {
+    jest.runOnlyPendingTimers();
+    jest.useRealTimers();
+  });
+
+  it('can return the first new result index when loading more posts', async () => {
+    const perPage = 5;
+    const { result } = renderHook(
+      () => usePostsList({ fetcher: fetchPostsList, perPage }),
+      { wrapper }
+    );
+
+    expect.assertions(2);
+
+    expect(result.current.firstNewResultIndex).toBeUndefined();
+
+    await act(async () => {
+      await result.current.loadMore();
+    });
+
+    // Assuming there is more than one page.
+    expect(result.current.firstNewResultIndex).toBe(perPage + 1);
+  });
+});