Update Next.js 16

[luiztiago]

This pull request updates the project to support Next.js 16 and React 19, modernizes dependencies, and migrates ESLint configuration to the new flat config format. It also introduces a new proxy.ts middleware file to handle Next.js 16 middleware changes and ensure compatibility with VIP infrastructure.

Framework and Dependency Upgrades:

• Upgraded next to version 16.0.0, react and react-dom to 19.2.0, @apollo/client to 4.0.9, and updated related type packages to match new major versions. This ensures compatibility with the latest features and security patches. [1] [2]

ESLint Migration and Configuration:

• Migrated ESLint configuration to the new flat config format by adding eslint.config.mjs and updating lint scripts in package.json. Added new ESLint dependencies (@eslint/eslintrc, @eslint/js) and updated existing ones. [1] [2] [3]

Next.js Middleware Update:

• Added proxy.ts to replace the legacy middleware.ts, adapting to Next.js 16 conventions. This middleware removes the x-middleware-prefetch header, rewrites healthcheck requests, and sets VIP-specific headers to ensure correct error page handling.

Version Bump:

• Updated the project version in package.json from 0.1.0 to 0.2.0 to reflect significant changes.

[Copilot]

Pull request overview

This PR upgrades the project to Next.js 16 and React 19, modernizes the dependency stack, and migrates to ESLint's flat configuration format. A new proxy.ts middleware file is introduced to maintain VIP infrastructure compatibility.

Key Changes:

• Upgraded core frameworks: Next.js to 16.0.0, React and React-DOM to 19.2.0, and Apollo Client to 4.0.9
• Migrated ESLint from legacy .eslintrc to flat config format (eslint.config.mjs) with ESLint 9.0.0
• Added proxy.ts middleware file with VIP-specific header handling and health check routing

Reviewed changes

Copilot reviewed 3 out of 6 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
package.json	Version bump to 0.2.0; upgraded Next.js, React, TypeScript, ESLint, and testing dependencies; updated lint scripts for flat config
proxy.ts	New middleware file handling VIP-specific headers, prefetch header removal, and health check rewrites
eslint.config.mjs	New ESLint flat config using FlatCompat for Next.js plugin compatibility
next.config.js	Added explicit image optimization defaults for Next.js 16 compatibility with explanatory comments
tsconfig.json	Changed jsx compiler from "preserve" to "react-jsx" for React 19 support

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[Copilot]

The new flat config is missing the editorconfig and jest plugins that were configured in the old .eslintrc file. These plugins provided important linting rules (e.g., editorconfig/indent, jest/recommended). Consider adding these plugins to the new config using FlatCompat or ensure the old .eslintrc file is removed to avoid configuration conflicts.

[luiztiago]

@copilot open a new pull request to apply changes based on this feedback

[Copilot]

This comment is incorrect. Next.js 16 did not rename middleware.ts to proxy.ts. The standard middleware convention still uses middleware.ts in Next.js 16. If proxy.ts is being used for VIP-specific infrastructure reasons, the comment should clarify that this is a VIP naming convention, not a Next.js 16 change.

Suggested change

	// Note: In Next.js 16, middleware.ts has been renamed to proxy.ts
	// Note: This file is named proxy.ts for VIP-specific infrastructure reasons.
	// The standard Next.js convention is still middleware.ts, even in Next.js 16.

[luiztiago]

https://nextjs.org/docs/messages/middleware-to-proxy

[Copilot]

@luiztiago I've opened a new pull request, #131, to work on those changes. Once the pull request is ready, I'll request review from you.

[ingeniumed]

I opened #132 with some fixes to get the skeleton working as right now, if you point it to a WP backend it fails. That can go into this branch

[chriszarate]

@Automattic/vip-platform-cantina Consider updating this repo with a note saying that it is purely an example, is not maintained, and could harbor future vulnerabilities. Then archive it (with or without this PR). Next.js is a markedly different (worse) framework compared to three years ago (when this repo was developed) and it is much less suitable to our platform.