feat: Recent flags (#7211)

frontend/src/component/feature/FeatureView/FeatureOverview/FeatureOverview.tsx

@@ -2,14 +2,18 @@ import FeatureOverviewMetaData from './FeatureOverviewMetaData/FeatureOverviewMe
 import FeatureOverviewEnvironments from './FeatureOverviewEnvironments/FeatureOverviewEnvironments';
 import { Route, Routes, useNavigate } from 'react-router-dom';
 import { SidebarModal } from 'component/common/SidebarModal/SidebarModal';
-import { formatFeaturePath } from 'component/feature/FeatureStrategy/FeatureStrategyEdit/FeatureStrategyEdit';
+import {
+    FeatureStrategyEdit,
+    formatFeaturePath,
+} from 'component/feature/FeatureStrategy/FeatureStrategyEdit/FeatureStrategyEdit';
 import { useRequiredPathParam } from 'hooks/useRequiredPathParam';
 import { usePageTitle } from 'hooks/usePageTitle';
 import { FeatureOverviewSidePanel } from 'component/feature/FeatureView/FeatureOverview/FeatureOverviewSidePanel/FeatureOverviewSidePanel';
 import { useHiddenEnvironments } from 'hooks/useHiddenEnvironments';
 import { styled } from '@mui/material';
 import { FeatureStrategyCreate } from 'component/feature/FeatureStrategy/FeatureStrategyCreate/FeatureStrategyCreate';
-import { FeatureStrategyEdit } from 'component/feature/FeatureStrategy/FeatureStrategyEdit/FeatureStrategyEdit';
+import { useEffect } from 'react';
+import { useLastViewedFlags } from 'hooks/useLastViewedFlags';
 
 const StyledContainer = styled('div')(({ theme }) => ({
     display: 'flex',
@@ -37,6 +41,10 @@ const FeatureOverview = () => {
         useHiddenEnvironments();
     const onSidebarClose = () => navigate(featurePath);
     usePageTitle(featureId);
+    const { setLastViewed } = useLastViewedFlags();
+    useEffect(() => {
+        setLastViewed({ featureId, projectId });
+    }, [featureId]);
 
     return (
         <StyledContainer>

frontend/src/component/layout/MainLayout/NavigationSidebar/NavigationList.tsx

@@ -18,6 +18,7 @@ import Accordion from '@mui/material/Accordion';
 import AccordionDetails from '@mui/material/AccordionDetails';
 import AccordionSummary from '@mui/material/AccordionSummary';
 import ExpandMoreIcon from '@mui/icons-material/ExpandMore';
+import FlagIcon from '@mui/icons-material/OutlinedFlag';
 
 const StyledBadgeContainer = styled('div')(({ theme }) => ({
     paddingLeft: theme.spacing(2),
@@ -119,6 +120,30 @@ export const RecentProjectsList: FC<{
     );
 };
 
+export const RecentFlagsList: FC<{
+    flags: { featureId: string; projectId: string }[];
+    mode: NavigationMode;
+    onClick: () => void;
+}> = ({ flags, mode, onClick }) => {
+    const DynamicListItem = mode === 'mini' ? MiniListItem : FullListItem;
+
+    return (
+        <List>
+            {flags.map((flag) => (
+                <DynamicListItem
+                    href={`/projects/${flag.projectId}/features/${flag.featureId}`}
+                    text={flag.featureId}
+                    onClick={onClick}
+                    selected={false}
+                    key={flag.featureId}
+                >
+                    <FlagIcon />
+                </DynamicListItem>
+            ))}
+        </List>
+    );
+};
+
 export const PrimaryNavigationList: FC<{
     mode: NavigationMode;
     onClick: (activeItem: string) => void;
@@ -226,3 +251,22 @@ export const RecentProjectsNavigation: FC<{
         </Box>
     );
 };
+
+export const RecentFlagsNavigation: FC<{
+    mode: NavigationMode;
+    flags: { featureId: string; projectId: string }[];
+    onClick: () => void;
+}> = ({ mode, onClick, flags }) => {
+    return (
+        <Box>
+            {mode === 'full' && (
+                <Typography
+                    sx={{ fontWeight: 'bold', fontSize: 'small', mb: 1, ml: 2 }}
+                >
+                    Recent flags
+                </Typography>
+            )}
+            <RecentFlagsList flags={flags} mode={mode} onClick={onClick} />
+        </Box>
+    );
+};

frontend/src/component/layout/MainLayout/NavigationSidebar/NavigationSidebar.test.tsx

@@ -4,6 +4,12 @@ import { screen, fireEvent, waitFor } from '@testing-library/react';
 import { createLocalStorage } from 'utils/createLocalStorage';
 import { Route, Routes } from 'react-router-dom';
 import { listItemButtonClasses as classes } from '@mui/material/ListItemButton';
+import {
+    type LastViewedFlag,
+    useLastViewedFlags,
+} from '../../../../hooks/useLastViewedFlags';
+import { type FC, useEffect } from 'react';
+import { useLastViewedProject } from '../../../../hooks/useLastViewedProject';
 
 beforeEach(() => {
     window.localStorage.clear();
@@ -69,3 +75,32 @@ test('select active item', async () => {
 
     expect(links[1]).toHaveClass(classes.selected);
 });
+
+const SetupComponent: FC<{ project: string; flags: LastViewedFlag[] }> = ({
+    project,
+    flags,
+}) => {
+    const { setLastViewed: setProject } = useLastViewedProject();
+    const { setLastViewed: setFlag } = useLastViewedFlags();
+
+    useEffect(() => {
+        setProject(project);
+        flags.forEach((flag) => {
+            setFlag(flag);
+        });
+    }, []);
+
+    return <NavigationSidebar />;
+};
+
+test('print recent projects and flags', async () => {
+    render(
+        <SetupComponent
+            project={'projectA'}
+            flags={[{ featureId: 'featureA', projectId: 'projectB' }]}
+        />,
+    );
+
+    await screen.findByText('projectA');
+    await screen.findByText('featureA');
+});

frontend/src/component/layout/MainLayout/NavigationSidebar/NavigationSidebar.tsx

@@ -7,12 +7,14 @@ import { useExpanded } from './useExpanded';
 import {
     OtherLinksList,
     PrimaryNavigationList,
+    RecentFlagsNavigation,
     RecentProjectsNavigation,
     SecondaryNavigation,
     SecondaryNavigationList,
 } from './NavigationList';
 import { useInitialPathname } from './useInitialPathname';
 import { useLastViewedProject } from 'hooks/useLastViewedProject';
+import { useLastViewedFlags } from 'hooks/useLastViewedFlags';
 
 export const MobileNavigationSidebar: FC<{ onClick: () => void }> = ({
     onClick,
@@ -56,8 +58,11 @@ export const NavigationSidebar = () => {
 
     const [activeItem, setActiveItem] = useState(initialPathname);
 
-    const { lastViewed } = useLastViewedProject();
-    const showRecentProject = mode === 'full' && lastViewed;
+    const { lastViewed: lastViewedProject } = useLastViewedProject();
+    const showRecentProject = mode === 'full' && lastViewedProject;
+
+    const { lastViewed: lastViewedFlags } = useLastViewedFlags();
+    const showRecentFlags = mode === 'full' && lastViewedFlags.length > 0;
 
     return (
         <StretchContainer>
@@ -111,7 +116,15 @@ export const NavigationSidebar = () => {
             {showRecentProject && (
                 <RecentProjectsNavigation
                     mode={mode}
-                    projectId={lastViewed}
+                    projectId={lastViewedProject}
+                    onClick={() => setActiveItem('/projects')}
+                />
+            )}
+
+            {showRecentFlags && (
+                <RecentFlagsNavigation
+                    mode={mode}
+                    flags={lastViewedFlags}
                     onClick={() => setActiveItem('/projects')}
                 />
             )}

frontend/src/hooks/useCustomEvent.ts

@@ -1,4 +1,4 @@
-import { useEffect } from 'react';
+import { useCallback, useEffect } from 'react';
 
 /**
  * A hook that provides methods to emit and listen to custom DOM events.
@@ -8,10 +8,10 @@ export const useCustomEvent = (
     eventName: string,
     handler: (event: CustomEvent) => void,
 ) => {
-    const emitEvent = () => {
+    const emitEvent = useCallback(() => {
         const event = new CustomEvent(eventName);
         document.dispatchEvent(event);
-    };
+    }, [eventName]);
 
     useEffect(() => {
         const eventListener = (event: Event) => handler(event as CustomEvent);

frontend/src/hooks/useLastViewedFlags.test.tsx

@@ -0,0 +1,82 @@
+import type React from 'react';
+import { render, screen, fireEvent } from '@testing-library/react';
+import { useLastViewedFlags } from './useLastViewedFlags';
+
+const TestComponent: React.FC<{
+    testId: string;
+    featureId: string;
+    projectId: string;
+}> = ({ testId, featureId, projectId }) => {
+    const { lastViewed, setLastViewed } = useLastViewedFlags();
+
+    const handleUpdate = () => {
+        setLastViewed({ featureId, projectId });
+    };
+
+    return (
+        <div>
+            <div data-testid={testId}>
+                {lastViewed.map((flag, index) => (
+                    <div
+                        key={index}
+                    >{`${flag.featureId} - ${flag.projectId}`}</div>
+                ))}
+            </div>
+            <button
+                type='button'
+                onClick={handleUpdate}
+                data-testid={`update-${testId}`}
+            >
+                Add {featureId} {projectId}
+            </button>
+        </div>
+    );
+};
+
+describe('Last three unique flags are persisted and duplicates are skipped', () => {
+    beforeEach(() => {
+        localStorage.clear();
+        render(
+            <>
+                <TestComponent
+                    testId='component1'
+                    featureId='Feature1'
+                    projectId='Project1'
+                />
+                <TestComponent
+                    testId='component2'
+                    featureId='Feature2'
+                    projectId='Project2'
+                />
+                <TestComponent
+                    testId='component3'
+                    featureId='Feature3'
+                    projectId='Project3'
+                />
+                <TestComponent
+                    testId='component4'
+                    featureId='Feature4'
+                    projectId='Project4'
+                />
+            </>,
+        );
+    });
+
+    it('only persists the last three unique flags across components and skips duplicates', async () => {
+        fireEvent.click(screen.getByTestId('update-component1'));
+        fireEvent.click(screen.getByTestId('update-component2'));
+        fireEvent.click(screen.getByTestId('update-component1')); // duplicate
+        fireEvent.click(screen.getByTestId('update-component3'));
+        fireEvent.click(screen.getByTestId('update-component4'));
+
+        expect(await screen.findAllByText('Feature2 - Project2')).toHaveLength(
+            4,
+        );
+        expect(await screen.findAllByText('Feature3 - Project3')).toHaveLength(
+            4,
+        );
+        expect(await screen.findAllByText('Feature4 - Project4')).toHaveLength(
+            4,
+        );
+    });
+});

frontend/src/hooks/useLastViewedFlags.ts

@@ -0,0 +1,55 @@
+import { useCallback, useEffect, useState } from 'react';
+import { getLocalStorageItem, setLocalStorageItem } from '../utils/storage';
+import { basePath } from 'utils/formatPath';
+import { useCustomEvent } from './useCustomEvent';
+
+const MAX_ITEMS = 3;
+
+export type LastViewedFlag = { featureId: string; projectId: string };
+
+const removeIncorrect = (flags?: any[]): LastViewedFlag[] => {
+    if (!Array.isArray(flags)) return [];
+    return flags.filter((flag) => flag.featureId && flag.projectId);
+};
+
+const localStorageItems = (key: string) => {
+    return removeIncorrect(getLocalStorageItem(key) || []);
+};
+
+export const useLastViewedFlags = () => {
+    const key = `${basePath}:unleash-lastViewedFlags`;
+    const [lastViewed, setLastViewed] = useState<LastViewedFlag[]>(() =>
+        localStorageItems(key),
+    );
+
+    const { emitEvent } = useCustomEvent(
+        'lastViewedFlagsUpdated',
+        useCallback(() => {
+            setLastViewed(localStorageItems(key));
+        }, [key]),
+    );
+
+    useEffect(() => {
+        if (lastViewed) {
+            setLocalStorageItem(key, lastViewed);
+            emitEvent();
+        }
+    }, [JSON.stringify(lastViewed), key, emitEvent]);
+
+    const setCappedLastViewed = useCallback(
+        (flag: { featureId: string; projectId: string }) => {
+            if (!flag.featureId || !flag.projectId) return;
+            if (lastViewed.find((item) => item.featureId === flag.featureId))
+                return;
+            const updatedLastViewed = removeIncorrect([...lastViewed, flag]);
+            setLastViewed(
+                updatedLastViewed.length > MAX_ITEMS
+                    ? updatedLastViewed.slice(-MAX_ITEMS)
+                    : updatedLastViewed,
+            );
+        },
+        [JSON.stringify(lastViewed)],
+    );
+
+    return { lastViewed, setLastViewed: setCappedLastViewed };
+};

frontend/src/hooks/useLastViewedProject.ts

@@ -19,7 +19,7 @@ export const useLastViewedProject = () => {
             setLocalStorageItem(key, lastViewed);
             emitEvent();
         }
-    }, [lastViewed, key]);
+    }, [lastViewed, key, emitEvent]);
 
     return {
         lastViewed,