test(dashboard): add vitest suite for heatmap component (JhaSourav07#836)

Author: JhaSourav07

components/dashboard/Heatmap.test.ts

@@ -0,0 +1,69 @@
+import { render, screen } from '@testing-library/react';
+import { describe, it, expect, vi, beforeAll } from 'vitest';
+import type { ReactNode, HTMLAttributes } from 'react';
+import Heatmap from './Heatmap';
+import type { ActivityData } from '@/types/dashboard';
+
+// 1. Mock ResizeObserver (JSDOM lacks it)
+beforeAll(() => {
+  global.ResizeObserver = class ResizeObserver {
+    observe() {}
+    unobserve() {}
+    disconnect() {}
+  };
+});
+
+// 2. Mock framer-motion with inline types to prevent hoisting errors
+vi.mock('framer-motion', () => ({
+  motion: {
+    div: (props: HTMLAttributes<HTMLDivElement> & { children?: ReactNode }) => (
+      <div
+        className={props.className}
+        style={props.style}
+        onMouseEnter={props.onMouseEnter}
+        onMouseLeave={props.onMouseLeave}
+      >
+        {props.children}
+      </div>
+    ),
+  },
+  AnimatePresence: ({ children }: { children?: ReactNode }) => <>{children}</>,
+}));
+
+describe('Heatmap', () => {
+  // Create a strongly typed empty array to fix the `data={[]}` red lines
+  const emptyData: ActivityData[] = [];
+
+  // Helper to generate properly typed mock data
+  const generateMockData = (days: number): ActivityData[] => {
+    return Array.from({ length: days }, (_, i) => ({
+      date: `2024-01-${(i % 28) + 1}`,
+      count: 5,
+      intensity: 2,
+    }));
+  };
+
+  it("renders 'Contribution Heatmap' heading", () => {
+    render(<Heatmap data={emptyData} />);
+    expect(screen.getByRole('heading', { name: /contribution heatmap/i })).toBeDefined();
+  });
+
+  it("renders 'Last 365 days' subtitle", () => {
+    render(<Heatmap data={emptyData} />);
+    expect(screen.getByText(/last 365 days/i)).toBeDefined();
+  });
+
+  it("renders 'Less' and 'More' legend labels", () => {
+    render(<Heatmap data={emptyData} />);
+    expect(screen.getByText(/less/i)).toBeDefined();
+    expect(screen.getByText(/more/i)).toBeDefined();
+  });
+
+  it('renders without crashing with an empty data array', () => {
+    expect(() => render(<Heatmap data={emptyData} />)).not.toThrow();
+  });
+
+  it('renders without crashing with 365 days of data', () => {
+    expect(() => render(<Heatmap data={generateMockData(365)} />)).not.toThrow();
+  });
+});