improve frontend test coverage

frontend/__tests__/unit/components/CardDetailsPage.test.tsx

@@ -1283,6 +1283,13 @@ describe('CardDetailsPage', () => {
       expect(screen.getByTestId('toggleable-list')).toHaveTextContent('Languages: JavaScript')
       expect(screen.queryByText('Topics:')).not.toBeInTheDocument()
     })
+
+    it('handles conditional rendering when languages empty but topics present', () => {
+      render(<CardDetailsPage {...defaultProps} languages={[]} topics={['web']} />)
+
+      expect(screen.getByTestId('toggleable-list')).toHaveTextContent('Topics: web')
+      expect(screen.queryByText('Languages:')).not.toBeInTheDocument()
+    })
   })
 
   describe('Accessibility and Semantic HTML', () => {
@@ -1611,6 +1618,25 @@ describe('CardDetailsPage', () => {
       expect(screen.getByText('Statistics')).toBeInTheDocument()
     })
 
+    it('handles undefined topics/languages in grid layout', () => {
+      render(<CardDetailsPage {...defaultProps} languages={['JavaScript']} topics={undefined} />)
+      expect(screen.getByTestId('toggleable-list')).toHaveTextContent('Languages: JavaScript')
+      cleanup()
+      render(<CardDetailsPage {...defaultProps} languages={undefined} topics={['web']} />)
+      expect(screen.getByTestId('toggleable-list')).toHaveTextContent('Topics: web')
+    })
+
+    it('renders Leaders with Unknown when value is null', () => {
+      const propsWithNullLeader = {
+        ...defaultProps,
+        type: 'chapter',
+        details: [{ label: 'Leaders', value: null }],
+      }
+      render(<CardDetailsPage {...propsWithNullLeader} />)
+      expect(screen.getByText('Leaders:')).toBeInTheDocument()
+      expect(screen.getByText('Unknown')).toBeInTheDocument()
+    })
+
     it('handles mixed valid and invalid data in arrays', () => {
       const mixedValidInvalidData = {
         ...defaultProps,
@@ -2083,6 +2109,39 @@ describe('CardDetailsPage', () => {
       expect(screen.getByText('Milestone No Author')).toBeInTheDocument()
     })
 
+    it('renders milestone author tooltip using login when name is missing', () => {
+      const milestonesWithAuthorNoName = [
+        {
+          author: {
+            login: 'author-login-only',
+            name: undefined,
+            avatarUrl: 'https://example.com/author-avatar.jpg',
+          },
+          body: 'Milestone with author no name',
+          closedIssuesCount: 3,
+          createdAt: new Date(Date.now() - 10000000).toISOString(),
+          openIssuesCount: 1,
+          repositoryName: 'test-repo',
+          organizationName: 'test-org',
+          state: 'open',
+          title: 'Milestone Author No Name',
+          url: 'https://github.com/test/project/milestone/1',
+        },
+      ]
+
+      const programProps: DetailsCardProps = {
+        ...defaultProps,
+        type: 'program' as const,
+        recentMilestones: milestonesWithAuthorNoName,
+        showAvatar: true,
+        modules: [],
+      }
+
+      render(<CardDetailsPage {...programProps} />)
+      expect(screen.getByTestId('mock-tooltip')).toHaveAttribute('title', 'author-login-only')
+      expect(screen.getByAltText("author-login-only's avatar")).toBeInTheDocument()
+    })
+
     it('renders milestone title without link when URL is missing', () => {
       const milestonesWithoutUrl = [
         {
@@ -2274,6 +2333,52 @@ describe('CardDetailsPage', () => {
       expect(screen.getByTestId('entity-actions')).toHaveTextContent('type=module')
     })
 
+    it('renders EntityActions for module type when user is a mentor but not admin', () => {
+      const { useSession } = jest.requireMock('next-auth/react')
+      useSession.mockReturnValue({
+        data: {
+          user: {
+            login: 'mentor-user',
+            name: 'Mentor User',
+            email: 'mentor@example.com',
+          },
+        },
+      })
+
+      const adminUser = {
+        id: 'admin-id',
+        login: 'admin-user',
+        name: 'Admin User',
+        avatarUrl: 'https://example.com/admin-avatar.jpg',
+      }
+
+      const mentorUser = {
+        id: 'mentor-id',
+        login: 'mentor-user',
+        name: 'Mentor User',
+        avatarUrl: 'https://example.com/mentor-avatar.jpg',
+      }
+
+      const moduleProps: DetailsCardProps = {
+        ...defaultProps,
+        type: 'module' as const,
+        accessLevel: 'admin',
+        admins: [adminUser],
+        mentors: [mentorUser],
+        programKey: 'test-program',
+        entityKey: 'test-module',
+        modules: [],
+      }
+
+      render(<CardDetailsPage {...moduleProps} />)
+
+      const entityActions = screen.getByTestId('entity-actions')
+      expect(entityActions).toBeInTheDocument()
+      expect(entityActions).toHaveTextContent('type=module')
+      // isAdmin should be undefined (user is not in admins list)
+      expect(entityActions).not.toHaveAttribute('data-isadmin', 'true')
+    })
+
     it('does not render EntityActions for module type when user is not an admin', () => {
       const { useSession } = jest.requireMock('next-auth/react')
       useSession.mockReturnValue({

frontend/__tests__/unit/components/ChapterMap.test.tsx

@@ -219,6 +219,30 @@ describe('ChapterMap Refactored Tests', () => {
       })
     })
 
+    it('removes existing zoom control before adding a new one on re-activation', async () => {
+      const { getByText, container } = render(<ChapterMap {...defaultProps} />)
+
+      fireEvent.click(getByText('Unlock map').closest('button'))
+      await waitFor(() => {
+        expect(L.control.zoom).toHaveBeenCalledTimes(1)
+        expect(mockZoomControl.addTo).toHaveBeenCalledTimes(1)
+      })
+
+      fireEvent.mouseLeave(container.firstChild as HTMLElement)
+      await waitFor(() => {
+        expect(mockZoomControl.remove).toHaveBeenCalled()
+        expect(getByText('Unlock map')).toBeInTheDocument()
+      })
+
+      jest.clearAllMocks()
+
+      fireEvent.click(getByText('Unlock map').closest('button'))
+      await waitFor(() => {
+        expect(L.control.zoom).toHaveBeenCalledTimes(1)
+        expect(mockZoomControl.addTo).toHaveBeenCalledTimes(1)
+      })
+    })
+
     it('locks map again on mouse leave', async () => {
       const { getByText, container } = render(<ChapterMap {...defaultProps} />)
 
@@ -266,6 +290,32 @@ describe('ChapterMap Refactored Tests', () => {
         expect(mockMap.setView).toHaveBeenCalledWith([35.6762, 139.6503], 7)
       })
     })
+
+    it('handles zero container height (aspect ratio 1)', async () => {
+      mockMap.getContainer.mockReturnValueOnce({
+        clientWidth: 800,
+        clientHeight: 0,
+      })
+
+      render(<ChapterMap {...defaultProps} />)
+      await waitFor(() => {
+        expect(mockMap.setMinZoom).toHaveBeenCalledWith(2)
+        expect(mockMap.setView).toHaveBeenCalledWith([20, 0], 2)
+      })
+    })
+
+    it('adjusts minZoom for wide aspect ratio (> 2)', async () => {
+      mockMap.getContainer.mockReturnValueOnce({
+        clientWidth: 1600,
+        clientHeight: 600,
+      })
+
+      render(<ChapterMap {...defaultProps} />)
+      await waitFor(() => {
+        expect(mockMap.setMinZoom).toHaveBeenCalledWith(1)
+        expect(mockMap.setView).toHaveBeenCalledWith([20, 0], 2)
+      })
+    })
   })
 
   describe('Share Location Button', () => {

frontend/__tests__/unit/components/EntityActions.test.tsx

@@ -1024,5 +1024,64 @@ describe('EntityActions', () => {
         )
       })
     })
+
+    it('skips cache update when getProgramModules is not in cache', async () => {
+      const mockCache = {
+        readQuery: jest.fn().mockReturnValue(null),
+        writeQuery: jest.fn(),
+      }
+
+      mockDeleteMutation.mockImplementationOnce(({ update }) => {
+        // eslint-disable-next-line @typescript-eslint/no-explicit-any
+        if (update) update(mockCache as any)
+        return Promise.resolve({ data: { deleteModule: true } })
+      })
+
+      render(
+        <EntityActions
+          type="module"
+          programKey="test-program"
+          moduleKey="test-module"
+          isAdmin={true}
+        />
+      )
+      fireEvent.click(screen.getByRole('button', { name: /Module actions menu/ }))
+      fireEvent.click(screen.getByText('Delete'))
+
+      fireEvent.click(screen.getByRole('button', { name: 'Delete' }))
+
+      await waitFor(() => {
+        expect(mockCache.readQuery).toHaveBeenCalled()
+        expect(mockCache.writeQuery).not.toHaveBeenCalled()
+        expect(mockPush).toHaveBeenCalledWith('/my/mentorship/programs/test-program')
+      })
+    })
+
+    it('handles non-Error thrown values gracefully', async () => {
+      mockDeleteMutation.mockRejectedValueOnce('string error')
+
+      render(
+        <EntityActions
+          type="module"
+          programKey="test-program"
+          moduleKey="test-module"
+          isAdmin={true}
+        />
+      )
+      fireEvent.click(screen.getByRole('button', { name: /Module actions menu/ }))
+      fireEvent.click(screen.getByText('Delete'))
+
+      fireEvent.click(screen.getByRole('button', { name: 'Delete' }))
+
+      await waitFor(() => {
+        expect(addToast).toHaveBeenCalledWith(
+          expect.objectContaining({
+            title: 'Error',
+            color: 'danger',
+            description: 'Failed to delete module. Please try again.',
+          })
+        )
+      })
+    })
   })
 })

frontend/__tests__/unit/components/ModuleForm.test.tsx

@@ -79,7 +79,7 @@ jest.mock('@heroui/react', () => ({
       <button
         type="button"
         data-testid="autocomplete-clear"
-        onClick={() => onSelectionChange?.(new Set())}
+        onClick={() => onSelectionChange?.(null)}
       >
         Clear Selection
       </button>
@@ -278,11 +278,16 @@ describe('ModuleForm', () => {
 
   beforeEach(() => {
     jest.clearAllMocks()
+    jest.useFakeTimers()
     mockQuery.mockResolvedValue({
       data: { searchProjects: [{ id: 'project-1', name: 'Test Project' }] },
     })
   })
 
+  afterEach(() => {
+    jest.useRealTimers()
+  })
+
   const renderModuleForm = (props = {}) => {
     const defaultProps = {
       formData: defaultFormData,
@@ -396,6 +401,51 @@ describe('ModuleForm', () => {
       }
       expect(mockSetFormData).toHaveBeenCalled()
     })
+
+    it('updates project field when ProjectSelector changes', async () => {
+      renderModuleForm()
+      const input = screen.getByTestId('autocomplete-input')
+      await act(async () => {
+        fireEvent.change(input, { target: { value: 'Test' } })
+        jest.advanceTimersByTime(350)
+      })
+      await waitFor(() => expect(mockQuery).toHaveBeenCalled())
+      const selectButton = screen.getByTestId('autocomplete-select-single')
+      await act(async () => {
+        fireEvent.click(selectButton)
+      })
+      expect(mockSetFormData).toHaveBeenCalled()
+      const setterFn = mockSetFormData.mock.calls[mockSetFormData.mock.calls.length - 1][0]
+      const result = setterFn(defaultFormData)
+      expect(result).toEqual(
+        expect.objectContaining({
+          projectId: 'project-1',
+          projectName: 'Test Project',
+        })
+      )
+    })
+
+    it('updates project field when ProjectSelector is cleared', async () => {
+      const initialFormData = {
+        ...defaultFormData,
+        projectId: 'proj-1',
+        projectName: 'Existing Project',
+      }
+      renderModuleForm({ formData: initialFormData })
+      const clearButton = screen.getByTestId('autocomplete-clear')
+      await act(async () => {
+        fireEvent.click(clearButton)
+      })
+      expect(mockSetFormData).toHaveBeenCalled()
+      const setterFn = mockSetFormData.mock.calls[mockSetFormData.mock.calls.length - 1][0]
+      const result = setterFn(initialFormData)
+      expect(result).toEqual(
+        expect.objectContaining({
+          projectId: '',
+          projectName: '',
+        })
+      )
+    })
   })
 
   describe('Experience Level Select - handleSelectChange (lines 74-84)', () => {
@@ -690,17 +740,16 @@ describe('ProjectSelector', () => {
       expect(mockOnProjectChange).toHaveBeenCalledWith('project-1', 'Test Project 1')
     })
 
-    it('clears selection when empty set is passed (lines 419-420)', async () => {
+    it('clears selection when clear button is clicked (lines 411-413)', async () => {
       renderProjectSelector({ value: 'project-1', defaultName: 'Existing Project' })
       const clearButton = screen.getByTestId('autocomplete-clear')
 
       await act(async () => {
         fireEvent.click(clearButton)
       })
 
-      // The component's handleSelectionChange doesn't handle empty Set directly
-      // This test verifies the current behavior where it's not called
-      expect(mockOnProjectChange).not.toHaveBeenCalled()
+      // Now expected to call onProjectChange with null
+      expect(mockOnProjectChange).toHaveBeenCalledWith(null, '')
     })
   })
 
@@ -778,6 +827,24 @@ describe('ProjectSelector', () => {
 
       consoleErrorSpy.mockRestore()
     })
+
+    it('handles missing searchProjects in response', async () => {
+      mockQuery.mockResolvedValue({ data: {} })
+
+      renderProjectSelector()
+      const input = screen.getByTestId('autocomplete-input')
+
+      await act(async () => {
+        fireEvent.change(input, { target: { value: 'Test' } })
+        jest.advanceTimersByTime(350)
+      })
+
+      await waitFor(() => {
+        expect(mockQuery).toHaveBeenCalled()
+      })
+      const items = screen.queryAllByTestId('autocomplete-item')
+      expect(items).toHaveLength(0)
+    })
   })
 
   describe('Validation Display', () => {