Fix loader breaking automatic JSX transform for files without workflow directives

[Copilot]

Files without "use workflow" or "use step" directives were failing SSR with ReferenceError: React is not defined. The loader was preventing Next.js from applying automatic JSX runtime transforms.

Changes

packages/next/src/loader.ts

• Use webpack callback API for pass-through instead of returning raw source
• When no directive found: callback(null, source, sourceMap) → allows Next.js SWC to process file
• Previously: return normalizedSource → blocked subsequent loaders

packages/next/src/index.ts

• Remove Turbopack rule configuration that overrode Next.js's built-in JSX handling
• Custom *.tsx/*.ts rules replaced default transforms, breaking files without directives

Why

In webpack, returning source from a loader marks the file as processed, skipping remaining loaders. In Turbopack, defining custom rules for file extensions replaces default handling entirely. Both prevented Next.js's automatic JSX transform (react/jsx-runtime) from running.

// Before: blocked Next.js transforms
if (!normalizedSource.match(/(use step|use workflow)/)) {
  return normalizedSource;
}

// After: passes through to Next.js loaders
if (!normalizedSource.match(/(use step|use workflow)/)) {
  return callback(null, source, sourceMap);
}

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• fonts.googleapis.com
  • Triggering command: /usr/local/bin/node /home/REDACTED/work/workflow/workflow/node_modules/.pnpm/next@15.5.4_@opentelemetry+api@1.9.0_react-dom@19.1.0_react@19.1.0__react@19.1.0/node_modules/next/dist/compiled/jest-worker/processChild.js (dns block)
  • Triggering command: node /home/REDACTED/work/workflow/workflow/workbench/nextjs-turbopack/node_modules/.bin/../next/dist/bin/next build --turbopack (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

Original prompt

---

This section details on the original issue you should resolve

<issue_title>@workflow/next loader breaks automatic JSX transform (React is not defined during SSR)</issue_title>
<issue_description>After enabling Workflow in next.config.mjs:

import { withWorkflow } from '@workflow/next';
export default withWorkflow({ reactStrictMode: true });

some .tsx files without "use workflow" or "use step" fail during SSR with:

ReferenceError: React is not defined

The generated server bundle contains React.createElement(...) but no import React, meaning the automatic JSX transform isn’t applied.

Findings

• The loader (@workflow/next/dist/loader.js) short-circuits by returning the raw source when no directive is found.
• Because it runs before Next’s SWC, those files skip the automatic JSX transform and fall back to the classic runtime.
• On branches without the Workflow wrapper, everything renders normally.

Expected
Files without Workflow directives should still use Next’s automatic JSX transform (react/jsx-runtime) and not require a React import.

Environment

• Next.js 16.0.1
• React 19
• @workflow/next 4.0.1-beta.6
• Node 22

---

Disclaimer: We are newcomers and this issue analysis was created using AI. Really sorry if this is not the correct way or place to open this issue.
</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes @workflow/next loader breaks automatic JSX transform (React is not defined during SSR) #212

---

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Project	Deployment	Preview	Comments	Updated (UTC)
example-nextjs-workflow-turbopack	Ready	Preview	Comment	Nov 7, 2025 8:37am
example-nextjs-workflow-webpack	Ready	Preview	Comment	Nov 7, 2025 8:37am
example-workflow	Ready	Preview	Comment	Nov 7, 2025 8:37am
workbench-nitro-workflow	Ready	Preview	Comment	Nov 7, 2025 8:37am
workbench-nuxt-workflow	Ready	Preview	Comment	Nov 7, 2025 8:37am
workbench-sveltekit-workflow	Ready	Preview	Comment	Nov 7, 2025 8:37am
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