mynode/packages/app-desktop/gui/NoteList/utils/UseAutoScroll.test.ts

import useAutoScroll from './useAutoScroll';
import { renderHook } from '@testing-library/react';

type Props = {
	selectedNoteId: string;
	selectedFolderId: string;
	targetIndex: number;
	makeItemIndexVisible: (index: number)=> void;
};

describe('UseAutoScroll', () => {

	test('scrolls to the note when a new note is selected', () => {
		const makeItemIndexVisible = jest.fn();

		renderHook(() => useAutoScroll('note-1', 'folder-1', 5, makeItemIndexVisible));

		expect(makeItemIndexVisible).toHaveBeenCalledTimes(1);
		expect(makeItemIndexVisible).toHaveBeenCalledWith(5);
	});

	test('does not scroll when the same note is already selected', () => {
		const makeItemIndexVisible = jest.fn();

		const { rerender } = renderHook(() =>
			useAutoScroll('note-1', 'folder-1', 5, makeItemIndexVisible),
		);

		makeItemIndexVisible.mockClear();
		rerender();

		expect(makeItemIndexVisible).not.toHaveBeenCalled();
	});

	test('does not scroll for multi-selection or no selection', () => {
		const makeItemIndexVisible = jest.fn();

		renderHook(() => useAutoScroll('', 'folder-1', -1, makeItemIndexVisible));

		expect(makeItemIndexVisible).not.toHaveBeenCalled();
	});

	test('defers scroll until notes load after folder change', () => {
		const makeItemIndexVisible = jest.fn();

		const { rerender } = renderHook(
			(props: Props) => useAutoScroll(
				props.selectedNoteId,
				props.selectedFolderId,
				props.targetIndex,
				props.makeItemIndexVisible,
			),
			{ initialProps: { selectedNoteId: 'note-1', selectedFolderId: 'folder-2', targetIndex: -1, makeItemIndexVisible } },
		);

		expect(makeItemIndexVisible).not.toHaveBeenCalled();

		rerender({ selectedNoteId: 'note-1', selectedFolderId: 'folder-2', targetIndex: 3, makeItemIndexVisible });

		expect(makeItemIndexVisible).toHaveBeenCalledTimes(1);
		expect(makeItemIndexVisible).toHaveBeenCalledWith(3);
	});

	test('scrolls again when the folder changes even if note ID is the same', () => {
		const makeItemIndexVisible = jest.fn();

		const { rerender } = renderHook(
			(props: Props) => useAutoScroll(
				props.selectedNoteId,
				props.selectedFolderId,
				props.targetIndex,
				props.makeItemIndexVisible,
			),
			{ initialProps: { selectedNoteId: 'note-1', selectedFolderId: 'folder-1', targetIndex: 2, makeItemIndexVisible } },
		);

		expect(makeItemIndexVisible).toHaveBeenCalledTimes(1);

		rerender({ selectedNoteId: 'note-1', selectedFolderId: 'folder-2', targetIndex: 2, makeItemIndexVisible });

		expect(makeItemIndexVisible).toHaveBeenCalledTimes(2);
	});

	test('does not scroll again when targetIndex changes after the pending flag is cleared', () => {
		// Covers the case where a sort or filter changes targetIndex without a new selection.
		// Without this guard, arrow-key navigation would trigger a spurious second scroll.
		const makeItemIndexVisible = jest.fn();

		const { rerender } = renderHook(
			(props: Props) => useAutoScroll(
				props.selectedNoteId,
				props.selectedFolderId,
				props.targetIndex,
				props.makeItemIndexVisible,
			),
			{ initialProps: { selectedNoteId: 'note-1', selectedFolderId: 'folder-1', targetIndex: 5, makeItemIndexVisible } },
		);

		expect(makeItemIndexVisible).toHaveBeenCalledTimes(1);

		rerender({ selectedNoteId: 'note-1', selectedFolderId: 'folder-1', targetIndex: 7, makeItemIndexVisible });

		expect(makeItemIndexVisible).toHaveBeenCalledTimes(1);
	});

});