From e380d28924c51fb1ff428f1ecae26d16479ab0f1 Mon Sep 17 00:00:00 2001
From: Mateusz Kwasniewski <kwasniewski.mateusz@gmail.com>
Date: Mon, 18 Dec 2023 14:13:32 +0100
Subject: [PATCH] feat: up and down arrow navigation for filter items (#5673)

---
 .../filter/FilterItem/FilterItem.test.tsx     | 30 ++++++++++-
 .../filter/FilterItem/FilterItem.tsx          | 52 +++++++++++++++++--
 2 files changed, 76 insertions(+), 6 deletions(-)

diff --git a/frontend/src/component/filter/FilterItem/FilterItem.test.tsx b/frontend/src/component/filter/FilterItem/FilterItem.test.tsx
index d9ddaa2c62..bcb4849784 100644
--- a/frontend/src/component/filter/FilterItem/FilterItem.test.tsx
+++ b/frontend/src/component/filter/FilterItem/FilterItem.test.tsx
@@ -1,4 +1,4 @@
-import { screen } from '@testing-library/react';
+import { screen, fireEvent } from '@testing-library/react';
 import { render } from 'utils/testRenderer';
 import { FilterItem, FilterItemParams, IFilterItemProps } from './FilterItem';
 
@@ -163,4 +163,32 @@ describe('FilterItem Component', () => {
             },
         ]);
     });
+
+    it('navigates between items with arrow keys', async () => {
+        setup(null);
+
+        const searchInput = await screen.findByPlaceholderText('Search');
+        fireEvent.keyDown(searchInput, { key: 'ArrowDown' });
+
+        const firstOption = screen.getByText('Option 1').closest('li')!;
+        expect(document.activeElement).toBe(firstOption);
+
+        fireEvent.keyDown(firstOption, { key: 'ArrowUp' });
+        expect(document.activeElement).toBe(searchInput);
+    });
+
+    it('selects an item with the Enter key', async () => {
+        const recordedChanges = setup(null);
+
+        const searchInput = await screen.findByPlaceholderText('Search');
+        fireEvent.keyDown(searchInput, { key: 'ArrowDown' });
+
+        const firstOption = screen.getByText('Option 1').closest('li')!;
+        fireEvent.keyDown(firstOption, { key: 'Enter' });
+
+        expect(recordedChanges).toContainEqual({
+            operator: 'IS',
+            values: ['1'],
+        });
+    });
 });
diff --git a/frontend/src/component/filter/FilterItem/FilterItem.tsx b/frontend/src/component/filter/FilterItem/FilterItem.tsx
index b98655e07c..639d6526b6 100644
--- a/frontend/src/component/filter/FilterItem/FilterItem.tsx
+++ b/frontend/src/component/filter/FilterItem/FilterItem.tsx
@@ -9,7 +9,6 @@ import {
     StyledTextField,
 } from './FilterItem.styles';
 import { FilterItemChip } from './FilterItemChip/FilterItemChip';
-import { onEnter } from '../../common/Search/SearchSuggestions/onEnter';
 
 export interface IFilterItemProps {
     name: string;
@@ -27,6 +26,37 @@ export type FilterItemParams = {
     values: string[];
 };
 
+interface UseSelectionManagementProps {
+    options: Array<{ label: string; value: string }>;
+    handleToggle: (value: string) => () => void;
+}
+
+const useSelectionManagement = ({
+    options,
+    handleToggle,
+}: UseSelectionManagementProps) => {
+    const listRefs = useRef<Array<HTMLInputElement | HTMLLIElement | null>>([]);
+
+    const handleSelection = (event: React.KeyboardEvent, index: number) => {
+        // we have to be careful not to prevent other keys e.g tab
+        if (event.key === 'ArrowDown' && index < listRefs.current.length - 1) {
+            event.preventDefault();
+            listRefs.current[index + 1]?.focus();
+        } else if (event.key === 'ArrowUp' && index > 0) {
+            event.preventDefault();
+            listRefs.current[index - 1]?.focus();
+        } else if (event.key === 'Enter') {
+            event.preventDefault();
+            if (index > 0) {
+                const listItemIndex = index - 1;
+                handleToggle(options[listItemIndex].value)();
+            }
+        }
+    };
+
+    return { listRefs, handleSelection };
+};
+
 export const FilterItem: FC<IFilterItemProps> = ({
     name,
     label,
@@ -92,6 +122,11 @@ export const FilterItem: FC<IFilterItemProps> = ({
         }
     };
 
+    const { listRefs, handleSelection } = useSelectionManagement({
+        options,
+        handleToggle,
+    });
+
     useEffect(() => {
         if (state && !currentOperators.includes(state.operator)) {
             onChange({
@@ -144,6 +179,10 @@ export const FilterItem: FC<IFilterItemProps> = ({
                                 </InputAdornment>
                             ),
                         }}
+                        inputRef={(el) => {
+                            listRefs.current[0] = el;
+                        }}
+                        onKeyDown={(event) => handleSelection(event, 0)}
                     />
                     <List sx={{ overflowY: 'auto' }} disablePadding>
                         {options
@@ -152,7 +191,7 @@ export const FilterItem: FC<IFilterItemProps> = ({
                                     .toLowerCase()
                                     .includes(searchText.toLowerCase()),
                             )
-                            .map((option) => {
+                            .map((option, index) => {
                                 const labelId = `checkbox-list-label-${option.value}`;
 
                                 return (
@@ -161,10 +200,13 @@ export const FilterItem: FC<IFilterItemProps> = ({
                                         dense
                                         disablePadding
                                         tabIndex={0}
-                                        onKeyDown={onEnter(
-                                            handleToggle(option.value),
-                                        )}
                                         onClick={handleToggle(option.value)}
+                                        ref={(el) => {
+                                            listRefs.current[index + 1] = el;
+                                        }}
+                                        onKeyDown={(event) =>
+                                            handleSelection(event, index + 1)
+                                        }
                                     >
                                         <StyledCheckbox
                                             edge='start'