chore(supabase): update readme and package.json testing instructions

Author: mandarini

packages/core/supabase-js/README.md

@@ -340,6 +340,66 @@ npx nx update:test-deps:bun supabase-js
 npx nx test:bun supabase-js
 ```
 
+#### Running Integration Tests Locally with Verdaccio
+
+For the most accurate testing that mirrors CI exactly, use a local Verdaccio registry. This approach:
+- Tests the actual published package (not just source code)
+- Mirrors the exact CI workflow
+- Works for all integration test types (Next.js, Expo, Bun, Deno)
+
+**Setup:**
+
+```bash
+# Terminal 1: Start local Verdaccio registry (stays running)
+npx nx local-registry
+
+# Terminal 2: Build and publish packages to local registry
+npx nx run-many --target=build --all
+npx nx populate-local-registry
+```
+
+**Run Integration Tests:**
+
+```bash
+# Example: Test with Bun
+cd packages/core/supabase-js/test/integration/bun
+echo 'registry=http://localhost:4873/' > .npmrc
+bun install
+bun test
+rm .npmrc  # Clean up
+cd ../../../..
+
+# Example: Test with Next.js
+cd packages/core/supabase-js/test/integration/next
+echo 'registry=http://localhost:4873/' > .npmrc
+npm install --legacy-peer-deps
+npm test
+rm .npmrc
+cd ../../../..
+
+# Example: Test with Expo
+cd packages/core/supabase-js/test/integration/expo
+echo 'registry=http://localhost:4873/' > .npmrc
+npm install
+npm test
+rm .npmrc
+cd ../../../..
+
+# Example: Test with Deno
+cd packages/core/supabase-js/test/deno
+echo 'registry=http://localhost:4873/' > .npmrc
+npm install
+npm test
+rm .npmrc
+cd ../../../..
+```
+
+**Tips:**
+- Keep Verdaccio running in Terminal 1 for multiple test runs
+- Only rebuild/republish when you change source code
+- Registry runs on `http://localhost:4873/`
+- To stop Verdaccio: Ctrl+C in Terminal 1
+
 #### WebSocket Browser Testing
 
 ```bash
@@ -358,46 +418,18 @@ cd ../../..
 
 #### CI/CD Testing
 
-When running on CI, the tests automatically use the latest dependencies from the root project. The CI pipeline:
-
-1. Builds the main project with current dependencies
-2. Creates a package archive (`.tgz`) with the latest versions
-3. Uses this archive in Expo, Next.js, Deno, and Bun tests to ensure consistency
-
-### Updating Test Dependencies
+When running on CI, the tests automatically publish packages to a local Verdaccio registry. The CI pipeline:
 
-The platform-specific tests (Expo, Next.js, Deno, Bun) use a packaged version of supabase-js rather than directly importing from source. This ensures they test the actual built package as it would be consumed by users.
-
-#### How It Works
-
-1. **Build** the current supabase-js package
-2. **Pack** it into a `.tgz` file (like `npm pack` does)
-3. **Copy** the `.tgz` to the test directory
-4. **Install** it in the test project
-
-This mimics how real users would install and use the package.
-
-#### Update Scripts
-
-```bash
-# Update ALL test environment dependencies at once
-# This builds, packs, and installs in all test directories
-npx nx update:test-deps supabase-js
-
-# Or update specific test environments:
-npx nx update:test-deps:expo supabase-js    # Expo/React Native only
-npx nx update:test-deps:next supabase-js    # Next.js only
-npx nx update:test-deps:deno supabase-js    # Deno only
-npx nx update:test-deps:bun supabase-js     # Bun only
-```
+1. Builds all packages with current dependencies
+2. Starts a local Verdaccio registry
+3. Publishes all packages to Verdaccio
+4. Integration tests install from Verdaccio, ensuring they test the actual built packages
 
-**When to Update:**
+### Local Testing with Your Changes
 
-- After making changes to the source code
-- Before running platform-specific tests locally
-- When debugging test failures that might be due to stale dependencies
+The platform-specific tests (Expo, Next.js, Deno, Bun) install from registries rather than directly importing from source. This ensures they test the actual built packages as they would be consumed by users.
 
-**Note:** CI automatically handles this, so manual updates are only needed for local development.
+**For local development:** Use the Verdaccio workflow described in "Running Integration Tests Locally with Verdaccio" above. This mirrors CI exactly and allows you to test your local changes before pushing.
 
 ### Test Coverage
 

packages/core/supabase-js/package.json

@@ -44,12 +44,7 @@
     "test:types": "tsd --files test/types/*.test-d.ts && jsr publish --dry-run --allow-dirty",
     "docs": "typedoc --entryPoints src/index.ts --out docs/v2",
     "docs:json": "typedoc --entryPoints src/index.ts --json docs/v2/spec.json --excludeExternals",
-    "serve:coverage": "npx nx test:coverage supabase-js && serve test/coverage",
-    "update:test-deps": "cd test/integration/expo && npm install && cd ../next && npm install --legacy-peer-deps && cd ../../deno && npm install && cd ../integration/bun && bun install",
-    "update:test-deps:expo": "cd test/integration/expo && npm install",
-    "update:test-deps:next": "cd test/integration/next && npm install --legacy-peer-deps",
-    "update:test-deps:deno": "cd test/deno && npm install",
-    "update:test-deps:bun": "cd test/integration/bun && bun install"
+    "serve:coverage": "npx nx test:coverage supabase-js && serve test/coverage"
   },
   "dependencies": {
     "@supabase/auth-js": "*",