test(themes): add nord theme validation tests (JhaSourav07#3061)

Author: JhaSourav07

lib/svg/nord.test.ts

@@ -0,0 +1,69 @@
+import { describe, it, expect } from 'vitest';
+import { themes } from './themes';
+import { generateSVG } from './generator';
+import { getLuminance } from './sanitizer';
+import type { BadgeParams, ContributionCalendar, StreakStats } from '../../types';
+
+describe('Nord Theme', () => {
+  const mockStats: StreakStats = {
+    currentStreak: 5,
+    longestStreak: 10,
+    totalContributions: 100,
+    todayDate: '2024-06-12',
+  };
+
+  const mockCalendar: ContributionCalendar = {
+    weeks: [
+      {
+        contributionDays: [{ contributionCount: 5, date: '2024-06-12' }],
+      },
+    ],
+  } as ContributionCalendar;
+
+  it('should exist as a theme key', () => {
+    expect(themes.nord).toBeDefined();
+  });
+
+  it('should have valid hex background color', () => {
+    expect(themes.nord.bg).toMatch(/^[0-9a-f]{6}$/i);
+  });
+
+  it('should have valid hex text color', () => {
+    expect(themes.nord.text).toMatch(/^[0-9a-f]{6}$/i);
+  });
+
+  it('should have valid hex accent color', () => {
+    expect(themes.nord.accent).toMatch(/^[0-9a-f]{6}$/i);
+  });
+
+  it('should generate SVG containing nord theme colors', () => {
+    const svg = generateSVG(
+      mockStats,
+      {
+        user: 'octocat',
+        bg: themes.nord.bg,
+        text: themes.nord.text,
+        accent: themes.nord.accent,
+      } as BadgeParams,
+      mockCalendar
+    );
+
+    expect(svg).toContain('<svg');
+    expect(svg).toContain('</svg>');
+    expect(svg.toLowerCase()).toContain(themes.nord.bg.toLowerCase());
+    expect(svg.toLowerCase()).toContain(themes.nord.text.toLowerCase());
+    expect(svg.toLowerCase()).toContain(themes.nord.accent.toLowerCase());
+  });
+
+  it('should provide sufficient contrast between bg and text', () => {
+    const bgLum = getLuminance(themes.nord.bg);
+    const textLum = getLuminance(themes.nord.text);
+
+    const lighter = Math.max(bgLum, textLum);
+    const darker = Math.min(bgLum, textLum);
+
+    const contrastRatio = (lighter + 0.05) / (darker + 0.05);
+
+    expect(contrastRatio).toBeGreaterThan(4.5);
+  });
+});