test(shared): add unit tests for getProfileUrl, getWebViewUrl, getDeepLinkUrl (#296)

Closes #10

- tests getProfileUrl('github', 'octocat') → https://github.com/octocat
- tests getWebViewUrl('linkedin', 'john') → correct LinkedIn webview URL
- tests getDeepLinkUrl('twitter', 'john') → correct Twitter deep link URL
- covers null returns for unsupported and unknown platforms
- follows existing Vitest describe/it/expect style

Co-authored-by: Amrit <amrit@example.com>

Author: amritbej

packages/shared/src/__tests__/platforms-url.test.ts

@@ -0,0 +1,62 @@
+import { describe, it, expect } from 'vitest';
+import { getProfileUrl, getWebViewUrl, getDeepLinkUrl } from '../platforms';
+
+// ─── getProfileUrl Tests ───
+
+describe('getProfileUrl', () => {
+  it('should return the correct GitHub profile URL', () => {
+    expect(getProfileUrl('github', 'octocat')).toBe('https://github.com/octocat');
+  });
+
+  it('should return the correct LinkedIn profile URL', () => {
+    expect(getProfileUrl('linkedin', 'john')).toBe('https://www.linkedin.com/in/john');
+  });
+
+  it('should return the correct Twitter profile URL', () => {
+    expect(getProfileUrl('twitter', 'john')).toBe('https://x.com/john');
+  });
+
+  it('should return empty string for an unknown platform', () => {
+    expect(getProfileUrl('nonexistent', 'user')).toBe('');
+  });
+});
+
+// ─── getWebViewUrl Tests ───
+
+describe('getWebViewUrl', () => {
+  it('should return the correct LinkedIn webview URL', () => {
+    expect(getWebViewUrl('linkedin', 'john')).toBe('https://www.linkedin.com/in/john');
+  });
+
+  it('should return the correct Twitter webview URL', () => {
+    expect(getWebViewUrl('twitter', 'john')).toBe('https://x.com/john');
+  });
+
+  it('should return null for platforms without a webview URL (github)', () => {
+    expect(getWebViewUrl('github', 'octocat')).toBeNull();
+  });
+
+  it('should return null for an unknown platform', () => {
+    expect(getWebViewUrl('nonexistent', 'user')).toBeNull();
+  });
+});
+
+// ─── getDeepLinkUrl Tests ───
+
+describe('getDeepLinkUrl', () => {
+  it('should return the correct Twitter deep link URL', () => {
+    expect(getDeepLinkUrl('twitter', 'john')).toBe('twitter://user?screen_name=john');
+  });
+
+  it('should return the correct LinkedIn deep link URL', () => {
+    expect(getDeepLinkUrl('linkedin', 'john')).toBe('linkedin://profile?id=john');
+  });
+
+  it('should return null for platforms without a deep link (github)', () => {
+    expect(getDeepLinkUrl('github', 'octocat')).toBeNull();
+  });
+
+  it('should return null for an unknown platform', () => {
+    expect(getDeepLinkUrl('nonexistent', 'user')).toBeNull();
+  });
+});