Improve frontend test coverage above 90% and add missing test files

frontend/__tests__/mockData/mockSnapshotData.ts

@@ -10,6 +10,7 @@ export const mockSnapshotDetailsData = {
     errorMessage: '',
     newReleases: [
       {
+        id: 'release-1',
         name: 'v0.9.2',
         publishedAt: '2024-12-13T14:43:46+00:00',
         tagName: 'v0.9.2',
@@ -24,6 +25,7 @@ export const mockSnapshotDetailsData = {
         },
       },
       {
+        id: 'release-2',
         name: 'Latest pre-release',
         publishedAt: '2024-12-13T13:17:30+00:00',
         tagName: 'pre-release',

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

@@ -46,6 +46,7 @@ jest.mock('utils/constants', () => ({
       links: [
         { text: 'About', href: '/about' },
         { text: 'Contribute', href: 'https://github.com/OWASP/Nest/blob/main/CONTRIBUTING.md' },
+        { text: 'Empty Href Link', href: '' }, // Empty href to test fallback
       ],
     },
     {
@@ -71,9 +72,19 @@ jest.mock('utils/constants', () => ({
   ],
 }))
 
-jest.mock('utils/env.client', () => ({
+// Create a mutable mock for environment variables
+let mockEnv = {
   ENVIRONMENT: 'production',
   RELEASE_VERSION: '1.2.3',
+}
+
+jest.mock('utils/env.client', () => ({
+  get ENVIRONMENT() {
+    return mockEnv.ENVIRONMENT
+  },
+  get RELEASE_VERSION() {
+    return mockEnv.RELEASE_VERSION
+  },
 }))
 
 import { FaGithub, FaSlack } from 'react-icons/fa6'
@@ -93,6 +104,10 @@ describe('Footer', () => {
 
   beforeEach(() => {
     jest.clearAllMocks()
+    mockEnv = {
+      ENVIRONMENT: 'production',
+      RELEASE_VERSION: '1.2.3',
+    }
   })
 
   afterEach(() => {
@@ -132,10 +147,12 @@ describe('Footer', () => {
           }
         }
       }
+
       for (const link of regularLinks) {
         const linkElement = screen.getByRole('link', { name: link.text })
         expect(linkElement).toBeInTheDocument()
-        expect(linkElement).toHaveAttribute('href', link.href)
+        const expectedHref = link.href || '/'
+        expect(linkElement).toHaveAttribute('href', expectedHref)
         expect(linkElement).toHaveAttribute('target', '_blank')
       }
 
@@ -266,63 +283,31 @@ describe('Footer', () => {
       expect(versionLink).toHaveAttribute('rel', 'noopener noreferrer')
     })
 
-    test('handles span elements correctly', () => {
-      renderFooter()
-
-      const spanText = screen.getByText('Plain Text')
-      expect(spanText.tagName).toBe('SPAN')
-      expect(spanText).toHaveClass('text-slate-600', 'dark:text-slate-400')
-    })
-  })
-
-  describe('Version Link Behavior', () => {
-    let originalEnvironment: string
-    let originalReleaseVersion: string
-    let envModule: typeof import('utils/env.client')
-
-    beforeEach(() => {
-      jest.clearAllMocks()
-      envModule = jest.requireMock<typeof import('utils/env.client')>('utils/env.client')
-      originalEnvironment = envModule.ENVIRONMENT
-      originalReleaseVersion = envModule.RELEASE_VERSION
-    })
-
-    afterEach(() => {
-      if (envModule) {
-        envModule.ENVIRONMENT = originalEnvironment
-        envModule.RELEASE_VERSION = originalReleaseVersion
-      }
-    })
-
-    test('renders version as commit link in staging environment', () => {
-      envModule.ENVIRONMENT = 'staging'
-      envModule.RELEASE_VERSION = '24.2.10-12c25c5'
+    test('renders version as commit link in non-production environment', () => {
+      // Set non-production environment with commit hash
+      mockEnv.ENVIRONMENT = 'staging'
+      mockEnv.RELEASE_VERSION = '24.2.10-12c25c5'
 
-      const { container } = render(<Footer />)
-      const versionLink = container.querySelector('a[href*="commit"]')
+      renderFooter()
 
+      const versionText = screen.getByText('v24.2.10-12c25c5')
+      const versionLink = versionText.closest('a')
       expect(versionLink).toBeInTheDocument()
       expect(versionLink).toHaveAttribute('href', 'https://github.com/OWASP/Nest/commit/12c25c5')
       expect(versionLink).toHaveAttribute('target', '_blank')
       expect(versionLink).toHaveAttribute('rel', 'noopener noreferrer')
-      expect(versionLink).toHaveTextContent('v24.2.10-12c25c5')
-    })
 
-    test('renders version as release tag link in production environment', () => {
-      envModule.ENVIRONMENT = 'production'
-      envModule.RELEASE_VERSION = '1.2.3'
+      // Reset to defaults to avoid leaking state
+      mockEnv.ENVIRONMENT = 'production'
+      mockEnv.RELEASE_VERSION = '1.2.3'
+    })
 
-      const { container } = render(<Footer />)
-      const versionLink = container.querySelector('a[href*="releases"]')
+    test('handles span elements correctly', () => {
+      renderFooter()
 
-      expect(versionLink).toBeInTheDocument()
-      expect(versionLink).toHaveAttribute(
-        'href',
-        'https://github.com/OWASP/Nest/releases/tag/1.2.3'
-      )
-      expect(versionLink).toHaveAttribute('target', '_blank')
-      expect(versionLink).toHaveAttribute('rel', 'noopener noreferrer')
-      expect(versionLink).toHaveTextContent('v1.2.3')
+      const spanText = screen.getByText('Plain Text')
+      expect(spanText.tagName).toBe('SPAN')
+      expect(spanText).toHaveClass('text-slate-600', 'dark:text-slate-400')
     })
   })
 
@@ -420,6 +405,13 @@ describe('Footer', () => {
       expect(aboutLink).toHaveAttribute('href', '/about')
     })
 
+    test('handles empty href with fallback to root path', () => {
+      renderFooter()
+
+      const emptyHrefLink = screen.getByRole('link', { name: 'Empty Href Link' })
+      expect(emptyHrefLink).toHaveAttribute('href', '/')
+    })
+
     test('handles sections with span elements', () => {
       renderFooter()
 

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

@@ -135,5 +135,45 @@ describe('HealthMetrics', () => {
       expect(props.days).toEqual([0, 0])
       expect(props.requirements).toEqual([0, 0])
     })
+
+    it('handles completely null/undefined optional fields', () => {
+      const nullData = [
+        {
+          createdAt: null,
+          openIssuesCount: null,
+          unassignedIssuesCount: undefined,
+          unansweredIssuesCount: null,
+          openPullRequestsCount: undefined,
+          starsCount: null,
+          forksCount: undefined,
+          id: 'null-test',
+          projectKey: 'null-project',
+        },
+      ]
+      // @ts-expect-error - testing specific edge case with mocked data
+      render(<HealthMetrics data={nullData} />)
+
+      // Verify LineCharts have 0s for data
+      const lineCharts = screen.getAllByTestId('LineChart')
+
+      // Issues Trend
+      const issuesProps = JSON.parse(lineCharts[0].dataset.props || '{}')
+      expect(issuesProps.series[0].data).toEqual([0]) // openIssuesCount
+      expect(issuesProps.series[1].data).toEqual([0]) // unassignedIssuesCount
+      expect(issuesProps.series[2].data).toEqual([0]) // unansweredIssuesCount
+      expect(issuesProps.labels).toEqual(['']) // createdAt
+
+      // Pull Requests Trend
+      const prProps = JSON.parse(lineCharts[1].dataset.props || '{}')
+      expect(prProps.series[0].data).toEqual([0]) // openPullRequestsCount
+
+      // Stars Trend
+      const starsProps = JSON.parse(lineCharts[2].dataset.props || '{}')
+      expect(starsProps.series[0].data).toEqual([0]) // starsCount
+
+      // Forks Trend
+      const forksProps = JSON.parse(lineCharts[3].dataset.props || '{}')
+      expect(forksProps.series[0].data).toEqual([0]) // forksCount
+    })
   })
 })

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

@@ -4,9 +4,11 @@ import React from 'react'
 import IssuesTable, { type IssueRow } from 'components/IssuesTable'
 import { LabelList } from 'components/LabelList'
 
+const mockPush = jest.fn()
+
 jest.mock('next/navigation', () => ({
   useRouter: () => ({
-    push: jest.fn(),
+    push: mockPush,
   }),
 }))
 
@@ -367,6 +369,26 @@ describe('<IssuesTable />', () => {
       const user4Texts = screen.getAllByText('user4')
       expect(user4Texts.length).toBeGreaterThan(0)
     })
+
+    it('uses name when login is not available', () => {
+      const issueWithoutLogin: IssueRow = {
+        objectID: '8-no-login',
+        number: 133,
+        title: 'Issue Without Login',
+        state: 'open',
+        labels: [],
+        assignees: [
+          {
+            avatarUrl: 'https://example.com/avatar5.jpg',
+            login: '',
+            name: 'User Five',
+          },
+        ],
+      }
+      render(<IssuesTable issues={[issueWithoutLogin]} />)
+      const user5Texts = screen.getAllByText('User Five')
+      expect(user5Texts.length).toBeGreaterThan(0)
+    })
   })
 
   describe('Click Handlers', () => {
@@ -378,6 +400,24 @@ describe('<IssuesTable />', () => {
       fireEvent.click(issueButtons[0])
       expect(onIssueClick).toHaveBeenCalledWith(123)
     })
+
+    it('navigates to issue URL when onIssueClick is not provided', () => {
+      const issueUrl = (num: number) => `/issues/${num}`
+      render(<IssuesTable {...defaultProps} onIssueClick={undefined} issueUrl={issueUrl} />)
+      const issueButtons = screen.getAllByRole('button', { name: /Test Issue 1/i })
+      expect(issueButtons.length).toBeGreaterThan(0)
+      fireEvent.click(issueButtons[0])
+      expect(mockPush).toHaveBeenCalledWith('/issues/123')
+    })
+
+    it('does nothing when onIssueClick and issueUrl are not provided', () => {
+      mockPush.mockClear()
+      render(<IssuesTable {...defaultProps} onIssueClick={undefined} issueUrl={undefined} />)
+      const issueButtons = screen.getAllByRole('button', { name: /Test Issue 1/i })
+      expect(issueButtons.length).toBeGreaterThan(0)
+      fireEvent.click(issueButtons[0])
+      expect(mockPush).not.toHaveBeenCalled()
+    })
   })
 
   describe('Empty State', () => {

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

@@ -0,0 +1,43 @@
+import { render, screen } from '@testing-library/react'
+import '@testing-library/jest-dom'
+import { LabelList } from 'components/LabelList'
+
+describe('LabelList', () => {
+  it('renders nothing when labels are empty', () => {
+    const { container } = render(<LabelList entityKey="test-1" labels={[]} />)
+    expect(container).toBeEmptyDOMElement()
+  })
+
+  it('renders nothing when labels are undefined', () => {
+    const { container } = render(<LabelList entityKey="test-2" labels={undefined} />)
+    expect(container).toBeEmptyDOMElement()
+  })
+
+  it('renders labels correctly', () => {
+    render(<LabelList entityKey="test-3" labels={['label1', 'label2']} />)
+    expect(screen.getByText('label1')).toBeInTheDocument()
+    expect(screen.getByText('label2')).toBeInTheDocument()
+  })
+
+  it('renders max visible labels and remaining count', () => {
+    render(<LabelList entityKey="test-4" labels={['1', '2', '3', '4', '5', '6']} maxVisible={5} />)
+    expect(screen.getByText('1')).toBeInTheDocument()
+    expect(screen.getByText('5')).toBeInTheDocument()
+    expect(screen.queryByText('6')).not.toBeInTheDocument()
+    expect(screen.getByText('+1 more')).toBeInTheDocument()
+  })
+
+  it('applies custom className', () => {
+    const { container } = render(
+      <LabelList entityKey="test-5" labels={['label']} className="custom-class" />
+    )
+    expect(container.firstChild).toHaveClass('custom-class')
+  })
+
+  it('renders all labels when maxVisible is greater than labels length', () => {
+    render(<LabelList entityKey="test-6" labels={['1', '2']} maxVisible={5} />)
+    expect(screen.getByText('1')).toBeInTheDocument()
+    expect(screen.getByText('2')).toBeInTheDocument()
+    expect(screen.queryByText(/\+\d+ more/)).not.toBeInTheDocument()
+  })
+})

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

@@ -443,6 +443,56 @@ describe('MovingLogos (LogoCarousel)', () => {
     })
   })
 
+  describe('Coverage Edge Cases', () => {
+    it('uses url for key generation when id is missing', () => {
+      const sponsor: Sponsor = {
+        id: undefined as unknown as string,
+        name: 'Name',
+        imageUrl: 'https://img.com',
+        url: 'https://url.com',
+        sponsorType: 'Gold',
+      }
+      render(<MovingLogos sponsors={[sponsor]} />)
+      expect(screen.getAllByTestId('sponsor-link')).toHaveLength(4)
+    })
+
+    it('uses name for key generation when id and url are missing', () => {
+      const sponsor: Sponsor = {
+        id: undefined as unknown as string,
+        name: 'Name',
+        imageUrl: 'https://img.com',
+        url: '',
+        sponsorType: 'Gold',
+      }
+      render(<MovingLogos sponsors={[sponsor]} />)
+      expect(screen.getAllByTestId('sponsor-link')).toHaveLength(4)
+    })
+
+    it('uses generic fallback for key generation when id, url, and name are missing', () => {
+      const sponsor: Sponsor = {
+        id: undefined as unknown as string,
+        name: '',
+        imageUrl: 'https://img.com',
+        url: '',
+        sponsorType: 'Gold',
+      }
+      render(<MovingLogos sponsors={[sponsor]} />)
+      expect(screen.getAllByTestId('sponsor-link')).toHaveLength(4)
+    })
+
+    it('renders generic "Sponsor" text when name and image are missing', () => {
+      const sponsor: Sponsor = {
+        id: '1',
+        name: '',
+        imageUrl: '',
+        url: 'https://url.com',
+        sponsorType: 'Gold',
+      }
+      render(<MovingLogos sponsors={[sponsor]} />)
+      expect(screen.getAllByText('Sponsor')).toHaveLength(2)
+    })
+  })
+
   describe('Accessibility Roles and Labels', () => {
     it('provides proper alt text for images', () => {
       render(<MovingLogos sponsors={mockSponsors} />)

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

@@ -99,4 +99,20 @@ describe('MetricsCard component', () => {
     expect(screen.getByText(/Score:/).textContent).toContain('55')
     expect(screen.getByRole('link')).toHaveAttribute('href', '/projects/dashboard/metrics/another')
   })
+
+  it('handles undefined optional props using defaults', () => {
+    const metric = makeMetric({
+      score: undefined,
+      createdAt: undefined,
+    })
+    render(<MetricsCard metric={metric} />)
+
+    // Score defaults to 0, so it should be red (< 50)
+    const scoreText = screen.getByText(/Score: 0/)
+    expect(scoreText).toBeInTheDocument()
+    expect(scoreText.closest('div')).toHaveClass('bg-red-500')
+
+    // createdAt defaults to "N/A"
+    expect(screen.getByText('N/A')).toBeInTheDocument()
+  })
 })