refactor: extract profile url logic (JhaSourav07#2240)

## Description

Moves PROFILE_URL and BASE_ORIGIN out of hooks/useShareActions.ts into a
centralised utils/urls.ts module, exposing:

- getOrigin() — resolves the site origin with SSR fallback
(window.location.origin → NEXT_PUBLIC_SITE_URL →
https://commitpulse.vercel.app)
- getDashboardUrl(username) — builds the full dashboard profile URL

- All 8 call sites in useShareActions.ts updated to use the new helpers.
Unit tests cover all three fallback paths for both functions.

**Note: The PROFILE_URL function and BASE_ORIGIN are defined at the top
of hooks/useShareActions.ts (not ShareSheet.tsx as the issue says).**

Fixes JhaSourav07#356

## Pillar

- [ ] 🎨 Pillar 1 — New Theme Design
- [ ] 📐 Pillar 2 — Geometric SVG Improvement
- [ ] 🕐 Pillar 3 — Timezone Logic Optimization
- [x] 🛠️ Other (Bug fix, refactoring, docs)

## Visual Preview
N/A

## Checklist before requesting a review:

- [x] I have read the `CONTRIBUTING.md` file.
- [ ] I have tested these changes locally
(`localhost:3000/api/streak?user=YOUR_USERNAME`).
- [x] I have run `npm run format` and `npm run lint` locally and
resolved all errors (CI will fail otherwise).
- [x] My commits follow the Conventional Commits format (e.g.,
`feat(themes): ...`, `fix(calculate): ...`).
- [x] I have updated `README.md` if I added a new theme or URL
parameter.
- [x] I have started the repo.
- [x] I have made sure that i have only one commit to merge in this PR.
- [x] The SVG output matches the CommitPulse "premium quality" aesthetic
standard (no raw elements, smooth animations, correct fonts).
- [x] (Recommended) I joined the CommitPulse Discord community for
contributor discussions, mentorship, and faster PR support.

Author: JhaSourav07

hooks/useShareActions.ts

@@ -2,15 +2,10 @@
 import { useState, useRef, useEffect } from 'react';
 import { toPng, toCanvas } from 'html-to-image';
 import type { DashboardExportData } from '@/types/dashboard';
+import { getDashboardUrl, getOrigin } from '@/utils/urls';
 
 type OptionState = 'idle' | 'loading' | 'success' | 'error';
 
-const BASE_ORIGIN =
-  (typeof window !== 'undefined' ? window.location.origin : null) ??
-  process.env.NEXT_PUBLIC_SITE_URL ??
-  'https://commitpulse.vercel.app';
-const PROFILE_URL = (username: string) => `${BASE_ORIGIN}/dashboard/${username}`;
-
 const SVG_NAMESPACE = 'http://www.w3.org/2000/svg';
 const XLINK_NAMESPACE = 'http://www.w3.org/1999/xlink';
 const UNSAFE_SVG_ELEMENTS = new Set([
@@ -48,7 +43,7 @@ function sanitizeFilenameSegment(value: string): string {
 }
 
 function buildStreakSvgUrl(username: string): string {
-  const url = new URL('/api/streak', BASE_ORIGIN);
+  const url = new URL('/api/streak', getOrigin());
   url.searchParams.set('user', sanitizeUsernameForUrl(username));
   return url.toString();
 }
@@ -147,7 +142,7 @@ export function useShareActions(
   const handleCopyLink = async (): Promise<boolean> => {
     setOptionState('copy', 'loading');
     try {
-      await navigator.clipboard.writeText(PROFILE_URL(username));
+      await navigator.clipboard.writeText(getDashboardUrl(username));
       setOptionState('copy', 'success');
       setTimeout(() => onClose(), 800);
       return true;
@@ -158,20 +153,20 @@ export function useShareActions(
   };
 
   const handleTwitter = () => {
-    const url = PROFILE_URL(username);
+    const url = getDashboardUrl(username);
     const text = encodeURIComponent(`Check out my GitHub commit pulse on CommitPulse 🚀\n${url}`);
     window.open(`https://twitter.com/intent/tweet?text=${text}`, '_blank', 'noopener');
     onClose();
   };
 
   const handleLinkedIn = () => {
-    const url = encodeURIComponent(PROFILE_URL(username));
+    const url = encodeURIComponent(getDashboardUrl(username));
     window.open(`https://www.linkedin.com/sharing/share-offsite/?url=${url}`, '_blank', 'noopener');
     onClose();
   };
 
   const handleReddit = () => {
-    const url = encodeURIComponent(PROFILE_URL(username));
+    const url = encodeURIComponent(getDashboardUrl(username));
     const title = encodeURIComponent('Check out my CommitPulse dashboard 🚀');
     window.open(
       `https://www.reddit.com/submit?url=${url}&title=${title}`,
@@ -356,7 +351,7 @@ export function useShareActions(
       const rows: Array<Array<string | number>> = [
         ['field', 'value'],
         ['username', username],
-        ['profileUrl', PROFILE_URL(username)],
+        ['profileUrl', getDashboardUrl(username)],
         ['exportedAt', exportedAt],
         ['totalContributions', exportData.stats.totalContributions],
         ['currentStreak', exportData.stats.currentStreak],
@@ -388,7 +383,7 @@ export function useShareActions(
 
       const payload = {
         username,
-        profileUrl: PROFILE_URL(username),
+        profileUrl: getDashboardUrl(username),
         exportedAt: new Date().toISOString(),
         totalContributions: exportData.stats.totalContributions,
         currentStreak: exportData.stats.currentStreak,
@@ -422,7 +417,7 @@ export function useShareActions(
       await navigator.share({
         title: `${username}'s Commit Pulse`,
         text: `Check out my GitHub commit pulse on CommitPulse 🚀`,
-        url: PROFILE_URL(username),
+        url: getDashboardUrl(username),
       });
       setOptionState('native', 'success');
       setTimeout(() => onClose(), 800);

utils/urls.test.ts

@@ -0,0 +1,69 @@
+import { describe, it, expect, vi, afterEach } from 'vitest';
+import { getDashboardUrl, getOrigin } from './urls';
+
+afterEach(() => {
+  vi.unstubAllGlobals();
+  delete process.env.NEXT_PUBLIC_SITE_URL;
+});
+
+describe('getOrigin', () => {
+  it('returns window.location.origin when window is defined', () => {
+    vi.stubGlobal('window', { location: { origin: 'https://example.com' } });
+
+    expect(getOrigin()).toBe('https://example.com');
+  });
+
+  it('falls back to NEXT_PUBLIC_SITE_URL when window is undefined', () => {
+    vi.stubGlobal('window', undefined);
+    process.env.NEXT_PUBLIC_SITE_URL = 'https://staging.commitpulse.app';
+
+    expect(getOrigin()).toBe('https://staging.commitpulse.app');
+  });
+
+  it('falls back to the hardcoded origin when both window and NEXT_PUBLIC_SITE_URL are absent', () => {
+    vi.stubGlobal('window', undefined);
+
+    expect(getOrigin()).toBe('https://commitpulse.vercel.app');
+  });
+
+  it('treats an empty NEXT_PUBLIC_SITE_URL as absent and falls back to the hardcoded origin', () => {
+    vi.stubGlobal('window', undefined);
+    process.env.NEXT_PUBLIC_SITE_URL = '';
+
+    expect(getOrigin()).toBe('https://commitpulse.vercel.app');
+  });
+
+  it('treats a whitespace-only NEXT_PUBLIC_SITE_URL as absent and falls back to the hardcoded origin', () => {
+    vi.stubGlobal('window', undefined);
+    process.env.NEXT_PUBLIC_SITE_URL = '   ';
+
+    expect(getOrigin()).toBe('https://commitpulse.vercel.app');
+  });
+});
+
+describe('getDashboardUrl', () => {
+  it('returns the correct dashboard URL using window.location.origin', () => {
+    vi.stubGlobal('window', { location: { origin: 'https://example.com' } });
+
+    expect(getDashboardUrl('octocat')).toBe('https://example.com/dashboard/octocat');
+  });
+
+  it('falls back to NEXT_PUBLIC_SITE_URL when window is undefined', () => {
+    vi.stubGlobal('window', undefined);
+    process.env.NEXT_PUBLIC_SITE_URL = 'https://staging.commitpulse.app';
+
+    expect(getDashboardUrl('octocat')).toBe('https://staging.commitpulse.app/dashboard/octocat');
+  });
+
+  it('falls back to the hardcoded origin when both window and NEXT_PUBLIC_SITE_URL are absent', () => {
+    vi.stubGlobal('window', undefined);
+
+    expect(getDashboardUrl('octocat')).toBe('https://commitpulse.vercel.app/dashboard/octocat');
+  });
+
+  it('includes the username in the path', () => {
+    vi.stubGlobal('window', { location: { origin: 'https://example.com' } });
+
+    expect(getDashboardUrl('torvalds')).toBe('https://example.com/dashboard/torvalds');
+  });
+});

utils/urls.ts

@@ -0,0 +1,12 @@
+const FALLBACK_ORIGIN = 'https://commitpulse.vercel.app';
+
+export function getOrigin(): string {
+  const envOrigin = process.env.NEXT_PUBLIC_SITE_URL?.trim() || null;
+  return (
+    (typeof window !== 'undefined' ? window.location.origin : null) ?? envOrigin ?? FALLBACK_ORIGIN
+  );
+}
+
+export function getDashboardUrl(username: string): string {
+  return `${getOrigin()}/dashboard/${encodeURIComponent(username)}`;
+}