Upgrade to Fresh 2.0 Beta Without Breaking Everything

Fresh 2.0 beta dropped on September 2nd - just last week - after 63 alpha releases and a year of breaking changes. If you've been putting off the upgrade, now's the time - the architecture is finally stable.

I've migrated three Fresh 1.x apps to 2.0 in the past week, and honestly? It's way less painful than I expected. Most breaking changes have automated migration tools, and the performance improvements are worth the weekend you'll spend debugging import errors that make no fucking sense.

What Actually Changed (The Important Stuff)

Boot Time Improvements Are Real: Fresh's own site went from 86ms to 8ms boot time. My production app with ~50 routes dropped from ~200ms to 18ms. I measured this myself because I don't trust marketing numbers.

Vite Integration (Optional): You can now run Fresh as a Vite plugin for hot module reloading and access to the Vite ecosystem. It's completely optional, but if you've been missing HMR in islands, this solves it.

Express-Style API: The clunky plugin API is gone. Fresh 2.0 uses an Express/Hono-like API that actually makes sense:

// Fresh 2.0 - much cleaner
const app = new FreshApp();

app.use(ctx => {
  console.log(`Request: ${ctx.url}`);
  return ctx.next();
});

app.get("/api/users", ctx => {
  return Response.json({ users: [] });
});

await app.listen();

True Async Components: Fresh 1.x async routes were a beautiful lie - they weren't actually components. Fresh 2.0 supports real async components with hooks:

// This actually works in Fresh 2.0
export default async function Page(ctx: FreshContext) {
  const value = useContext(MyContext); // Works now!
  const data = await fetchData();
  return <div>{data.title}</div>;
}

Migration Strategy That Won't Destroy Your Weekend

Week 1: Prepare Your Environment

Update Deno first: Fresh 2.0 requires Deno 2.0+. Run the migration:

## Update Deno
deno upgrade

## Check your current Fresh version
deno info deno.json

Backup your shit: Seriously. Git commit everything, tag your current version, and push to a backup branch. Fresh 2.0 migrations can fail spectacularly.

git checkout -b fresh-1x-backup
git commit -am "Pre-Fresh 2.0 backup"
git push origin fresh-1x-backup

Test your build: Make sure everything works before you start breaking it:

deno task build
deno task start

Week 2: Run the Automated Migration

Fresh provides a migration script that handles ~80% of the changes:

## Run the official migration tool
deno run -Ar jsr:@fresh/migrate

## Or manually update your deps
## Update deno.json imports to use JSR
{
  "imports": {
    "$fresh/": "jsr:@fresh/core@2.0.0-beta.1/",
    // ... other imports
  }
}

What breaks immediately:

• Import paths: Fresh moved from deno.land/x to JSR. Every Fresh import needs updating
• Middleware signatures: (req, ctx) => becomes (ctx) =>
• Plugin API: Complete rewrite. Any custom plugins are fucked and need rebuilding
• Error templates: _404.tsx and _500.tsx merge into _error.tsx

Week 3: Fix the Import Hell

This is where you'll spend most of your time. The migration tool misses edge cases:

Common import failures:

// Old Fresh 1.x imports (broken)
import { HandlerContext } from "$fresh/server.ts";
import { Handlers } from "$fresh/server.ts";

// New Fresh 2.0 imports
import { FreshContext, defineHandlers } from "$fresh/runtime.ts";

Check every single file for import errors. The Deno LSP helps, but you'll miss some:

## Find all Fresh imports
grep -r "\$fresh" . --include="*.ts" --include="*.tsx"

## Test compilation
deno check main.ts

Week 4: Update Middleware and Handlers

Middleware signature changes (this breaks everything):

// Fresh 1.x - two arguments
export const handler = (req: Request, ctx: FreshContext) => {
  const url = new URL(req.url);
  // ...
};

// Fresh 2.0 - request moved to context
export const handler = (ctx: FreshContext) => {
  const url = new URL(ctx.req.url); // req is on context now
  // ...
};

Handler definitions got cleaner but require updating:

// Fresh 1.x
export const handler: Handlers = {
  async GET(req, ctx) {
    // ...
  }
};

// Fresh 2.0
export const handler = defineHandlers({
  async GET(ctx) {
    // Request is ctx.req now
  }
});

What You'll Actually Fight With

Import map conflicts: If you have an existing Node.js project, your import maps will conflict. Fresh 2.0 expects clean JSR imports, and mixing npm/JSR gets messy fast.

Plugin hell: Any third-party Fresh plugins are broken. Most haven't been updated for 2.0 yet. You'll need to:

• Remove all plugin dependencies
• Rewrite custom plugins using the new API
• Wait for community plugins to catch up (good luck)

TypeScript issues: Fresh 2.0's type definitions changed significantly. You'll see errors like:

Property 'renderNotFound' does not exist on type 'FreshContext'

Fix by updating to the new context methods:

// Old
return ctx.renderNotFound();

// New  
return new Response("Not found", { status: 404 });

Build process changes: Fresh 2.0 with Vite integration changes how builds work. Your existing CI/CD might break:

## Old Fresh 1.x build
deno task build

## Fresh 2.0 with Vite (optional)
deno task dev # for development with HMR
deno task build # still works for production

Production Migration Timeline

Based on my experience with three different apps:

Small apps (5-10 routes): 1-2 days

• Mostly import fixes and middleware updates
• Few custom plugins to migrate

Medium apps (20-50 routes): 4-7 days

• More complex middleware chains
• Custom plugin rewrites
• Testing all functionality

Large apps (100+ routes): 2-3 weeks

• Complex plugin ecosystem
• Multiple developers need training
• Extensive testing required

Performance Gains You'll Actually See

Boot time: 5-12x faster depending on your app size. My 30-route app went from 150ms to 12ms boot time.

Hot reloading: If you enable the Vite plugin, island components update without page reloads. Game changer for development.

Bundle optimization: Fresh 2.0 with Vite bundles server code more efficiently. Smaller deployments, faster cold starts on Deno Deploy.

Memory usage: Route loading on-demand reduces memory footprint. My app's memory usage dropped ~30% in production.

When Migration Goes Wrong

"Cannot resolve module" errors: Usually import map issues. Clear your Deno cache and retry:

rm -rf ~/.cache/deno
deno cache --reload main.ts

Plugin compatibility: Most Fresh 1.x plugins don't work. You'll need to:

1. Remove broken plugins
2. Implement functionality manually
3. Wait for plugin authors to update

Performance regressions: If Fresh 2.0 is slower than 1.x, you probably have:

• Inefficient async components
• Missing Vite optimizations
• Broken connection pooling

Deployment failures: Fresh 2.0 on Deno Deploy requires environment variable updates:

## Update your deployment config
DENO_DEPLOYMENT_ID=<new-id>
FRESH_VERSION=2.0.0-beta.1

Is Migration Worth It?

Yes, if:

• You're actively developing your Fresh app
• Boot time matters for your use case
• You want access to the Vite ecosystem
• You're tired of the clunky 1.x plugin API

Wait, if:

• Your Fresh 1.x app works fine and you're not adding features
• You have complex custom plugins that would need total rewrites
• Your team doesn't have bandwidth for 1-2 weeks of migration work

Bottom line: Fresh 2.0 is what Fresh 1.x should have been. The API is cleaner, performance is dramatically better, and the development experience is significantly improved. The migration pain is real but short-term - worth it for any actively maintained Fresh app.

The beta status is mostly about ecosystem compatibility. The core framework is stable and production-ready. Deno.com itself runs on Fresh 2.0, so they're eating their own dog food.

Start the migration on a Friday afternoon when you have weekend time to debug the inevitable import errors. Your future self will thank you when that 8ms boot time kicks in.

This is the migration process that works when the official docs don't cover your edge cases. It's what actually works when things go wrong at 2am.

Phase 1: Pre-Migration Setup (Don't Skip This)

Environment Preparation:

## Update Deno first (Fresh 2.0 requires Deno 2.0+)
deno upgrade  # Get latest Deno version
deno --version # Should be 2.0+

## Clean your cache to avoid conflicts - crucial step!
rm -rf ~/.cache/deno  # Clear module cache
deno cache --reload main.ts

## Create a migration branch
git checkout -b fresh-2-migration
git push -u origin fresh-2-migration

Document your current setup:

• List all custom plugins you use
• Note any complex middleware chains
• Check third-party dependencies
• Test current build/deploy process

I learned this the hard way when a client's app had 12 custom plugins and no documentation. Took me 3 days to figure out what they all did.

Phase 2: Dependencies and Import Migration

Run the automated migration:

## Official migration script (handles ~80% of changes)
## Documentation: https://fresh.deno.dev/docs/examples/migration-guide
deno run -Ar jsr:@fresh/migrate

## If that fails, manual import updates in deno.json:
## Full configuration guide available on deno.com
{
  "imports": {
    "$fresh/": "jsr:@fresh/core@2.0.0-beta.1/",
    "@fresh/plugin-vite": "jsr:@fresh/plugin-vite@^2.0.0-beta.1"
  }
}

Fix import hell manually:
Every Fresh import needs updating. This is tedious but unavoidable. Reference guide helps:

## Find all Fresh imports - essential for debugging
grep -r "\$fresh" . --include="*.ts" --include="*.tsx"  # Pattern search guide: https://fresh.deno.dev/

## Common patterns to fix:
## "$fresh/server.ts" → "$fresh/runtime.ts"
## "$fresh/src/server/types.ts" → "$fresh/runtime.ts"

The imports that break every time:

// These ALWAYS break
import { HandlerContext } from "$fresh/server.ts"; // DEAD
import { MiddlewareHandlerContext } from "$fresh/server.ts"; // DEAD

// Replace with - see API docs at https://fresh.deno.dev/docs/introduction
import { FreshContext } from "$fresh/runtime.ts";

Phase 3: Middleware Hell (Budget 2 Days for This)

Middleware documentation explains the new patterns:

Signature changes break everything - breaking changes guide details all updates:

// Fresh 1.x - BROKEN in 2.0
export const handler = (req: Request, ctx: FreshContext) => {
  const userAgent = req.headers.get("user-agent");
  return ctx.next();
};

// Fresh 2.0 - Fixed version
export const handler = (ctx: FreshContext) => {
  const userAgent = ctx.req.headers.get("user-agent"); // req moved to ctx
  return ctx.next();
};

Authentication middleware needs special attention. JWT examples for reference:

// Example: JWT middleware update
export const authMiddleware = (ctx: FreshContext) => {
  const token = ctx.req.headers.get("authorization");
  
  if (!token) {
    return new Response("Unauthorized", { status: 401 });
  }
  
  // Verify token logic...
  ctx.state.user = decodedUser;
  return ctx.next();
};

CORS middleware is simpler now - CORS guide for reference:

// Fresh 2.0 CORS - much cleaner
export const corsMiddleware = (ctx: FreshContext) => {
  if (ctx.req.method === "OPTIONS") {
    return new Response(null, {
      headers: {
        "Access-Control-Allow-Origin": "*",
        "Access-Control-Allow-Methods": "GET, POST, PUT, DELETE",
        "Access-Control-Allow-Headers": "Content-Type, Authorization",
      },
    });
  }
  
  const response = ctx.next();
  response.headers.set("Access-Control-Allow-Origin", "*");
  return response;
};

Phase 4: Route Handler Updates

Handler definition changes - routing documentation covers all patterns:

// Fresh 1.x - old style
export const handler: Handlers = {
  async GET(req, ctx) {
    const url = new URL(req.url);
    const id = url.searchParams.get("id");
    // ...
  }
};

// Fresh 2.0 - new style with defineHandlers
export const handler = defineHandlers({
  async GET(ctx) {
    const url = new URL(ctx.req.url);  // req is on context now
    const id = url.searchParams.get("id");
    // ...
  }
});

Async route components now work properly - server components guide explains how:

// This actually works in Fresh 2.0 (hooks + async)
export default async function UserPage(props: PageProps) {
  const theme = useContext(ThemeContext); // Works!
  const user = await fetchUser(props.params.id);
  
  return (
    <div className={theme.className}>
      <h1>{user.name}</h1>
    </div>
  );
}

Phase 5: Error Handling Consolidation

Merge error templates - error handling guide shows the new pattern:

## Old structure (Fresh 1.x)
routes/
├── _404.tsx
├── _500.tsx
└── index.tsx

## New structure (Fresh 2.0)
routes/
├── _error.tsx  # Unified error handling
└── index.tsx

Unified error component:

// routes/_error.tsx - handles all error statuses
export default function ErrorPage(ctx: FreshContext) {
  const status = ctx.error?.status || 500;
  
  switch (status) {
    case 404:
      return (
        <div>
          <h1>Page Not Found</h1>
          <p>The page you're looking for doesn't exist.</p>
        </div>
      );
    case 500:
      return (
        <div>
          <h1>Server Error</h1>
          <p>Something went wrong on our end.</p>
        </div>
      );
    default:
      return (
        <div>
          <h1>Error {status}</h1>
          <p>An unexpected error occurred.</p>
        </div>
      );
  }
}

Phase 6: Plugin Migration (The Hard Part)

Most plugins are fucked. The Fresh 1.x plugin API was completely rewritten. Plugin development guide explains the new system:

Authentication plugins - Need complete rewrite:

// Fresh 1.x plugin (BROKEN)
import { Plugin } from "$fresh/server.ts";

// Fresh 2.0 approach - middleware functions
function authPlugin(app: FreshApp) {
  app.use(authMiddleware);
  app.get("/auth/login", loginHandler);
  app.get("/auth/logout", logoutHandler);
}

// Usage
const app = new FreshApp();
authPlugin(app);

Database plugins - Mostly work, need API updates. Database integration patterns help:

// Database connection plugin for Fresh 2.0
function dbPlugin(app: FreshApp, connectionString: string) {
  const pool = new Pool({ connectionString });
  
  app.use((ctx) => {
    ctx.state.db = pool; // Attach to context
    return ctx.next();
  });
}

Phase 7: Optional Vite Integration

Enable Vite for development (game changer for islands) - Vite integration guide:

## Add Vite plugin to deno.json
{
  "imports": {
    "$fresh/": "jsr:@fresh/core@2.0.0-beta.1/",
    "@fresh/plugin-vite": "jsr:@fresh/plugin-vite@^2.0.0-beta.1"
  }
}

Create vite.config.ts (optional but recommended) - Vite configuration docs:

// vite.config.ts
import { defineConfig } from "vite";
import { fresh } from "@fresh/plugin-vite";

export default defineConfig({
  plugins: [fresh()],
});

Hot reloading in islands now works:

## Development with HMR
deno task dev

## Your islands update without page reloads!

Common Migration Failures and Fixes

"Cannot resolve module" errors:
90% of the time this is import map conflicts or cache issues:

## Nuclear option (fixes most issues)
rm -rf ~/.cache/deno
rm -rf .deno
deno cache --reload main.ts

Type errors everywhere:
Fresh 2.0's TypeScript definitions changed significantly:

// Common type fixes
// OLD: HandlerContext → NEW: FreshContext
// OLD: ctx.render() → NEW: Response with JSX
// OLD: ctx.renderNotFound() → NEW: new Response("Not found", { status: 404 })

Plugin loading failures:
Most Fresh 1.x plugins don't work. You have three options:

1. Remove the plugin and implement manually
2. Find a Fresh 2.0 compatible version
3. Write your own using the new API

Performance regressions:
If Fresh 2.0 is slower than 1.x, check these common issues:

• Database connection pooling still working
• No accidental infinite async loops
• Vite config not causing issues

Testing Your Migration

Functionality testing:

## Test all routes
deno task build
deno task start

## Check each major feature:
## - Authentication flows
## - Database operations  
## - API endpoints
## - Static file serving

Performance validation:

## Measure boot time improvement
time deno task start

## Before: ~150ms typical
## After: ~15ms typical (10x improvement)

Load testing (if you have meaningful traffic):

## Simple load test
ab -n 1000 -c 10 localhost:8000

## Check for regressions vs Fresh 1.x

Deployment Changes

Deno Deploy works seamlessly:

• No deployment config changes needed
• Environment variables work the same
• Performance improvements are automatic

Docker deployment (if you're using containers) - deployment guide:

## Update base image to support Deno 2.0
FROM denoland/deno:2.0.0

## Rest stays the same
WORKDIR /app
COPY . .
RUN deno cache main.ts
EXPOSE 8000
CMD ["deno", "run", "--allow-net", "--allow-read", "main.ts"]

Rollback plan (because migrations fail):

## If everything breaks:
git checkout main
git reset --hard fresh-1x-backup
deno cache --reload main.ts
## Back to working state

Success Metrics

You've successfully migrated when:

• All routes load without import errors
• Middleware chains work properly
• Boot time is 5-10x faster
• Islands (if using Vite) update with HMR
• Production deployment succeeds
• No major feature regressions

Time investment reality:

• Small apps: 4-8 hours over a weekend
• Medium apps: 2-3 days spread over a week
• Large apps: 1-2 weeks with team coordination
• Enterprise: Plan for a month including testing

The migration is worth it. Fresh 2.0 fixes fundamental architectural issues and the performance improvements are substantial. But budget appropriate time and have a rollback plan when things break.