feat: Dual export pattern for clean bundler builds and Node.js compatibility

[mandarini]

What kind of change does this PR introduce?

Feature enhancement that provides a solution to bundler warnings while maintaining backward compatibility for Node.js < 22 users.

What is the current behavior?

Users see "Critical dependency: the request of a dependency is an expression" warnings in their bundlers due to dynamic imports in @supabase/realtime-js used for Node.js WebSocket detection.

What is the new behavior?

This PR introduces dual export paths to give users control over their build output:

📦 Main Export - Clean & Bundler-Friendly

import { createClient } from '@supabase/supabase-js'
- ✅ No bundler warnings
- ✅ Optimal for production builds
- ⚠️ Node.js < 22 users must provide WebSocket explicitly

🔧 Auto Export - Backward Compatible (Temporary)

import { createClient } from '@supabase/supabase-js/auto'
- ✅ Maintains current behavior with auto-detection
- ⚠️ Will show bundler warnings
- 🚨 **Deprecated** - Will be removed in v3.0.0

Breaking Changes

None for most users! However, Node.js < 22 users using the main export will need to provide WebSocket:

// Before
import { createClient } from '@supabase/supabase-js'
const supabase = createClient(url, key)

// After (Node.js < 22 only)
import { createClient } from '@supabase/supabase-js'
import ws from 'ws'
const supabase = createClient(url, key, {
  realtime: {
    transport: ws
  }
})

User Impact & Migration

Environment	Impact	Action Required
Browser	None	No changes
Edge Runtime	None	No changes
Node.js 22+	None	No changes
Node.js < 22	Minor	Install ws and pass via options OR use /auto export

Implementation Details

• Updates @supabase/realtime-js to v2.16.0 with dual export support
• Adds /auto export path in package.json
• Creates SupabaseClient.auto.ts for backward compatibility
• Main export uses clean realtime-js without dynamic imports
• Auto export maintains dynamic imports for compatibility

Migration Timeline

• v2.x: Both exports available
• v3.0: Remove /auto export, require explicit transport for Node.js < 22

Related PRs

• feat: separate entry point for dynamic imports realtime-js#511 - Implements dual export pattern in realtime-js

[coveralls]

Pull Request Test Coverage Report for Build 16887185443

Details

• 0 of 74 (0.0%) changed or added relevant lines in 2 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-25.1%) to 49.734%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/index.auto.ts	0	14	0.0%
src/SupabaseClient.auto.ts	0	60	0.0%

Totals
Change from base Build 16805913259:	-25.1%
Covered Lines:	122
Relevant Lines:	220

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💛 - Coveralls