Migrating from Express

Shokupan is designed to feel familiar to Express developers. This guide shows you how to migrate your Express app.

Key Differences

1. Context vs Req/Res: Single ctx object instead of separate req and res
2. Return vs Send: Return values directly instead of calling res.json()
3. Built-in Parsing: Body parsing is automatic
4. Async by Default: All handlers are naturally async
5. Web Standards: Uses Headers, URL, Response from web standards

Basic Server

Express:

import express from 'express';
const app = express();
app.get('/', (req, res) => {
    res.json({ message: 'Hello' });
});
app.listen(3000);

Shokupan:

import { Shokupan } from 'shokupan';
const app = new Shokupan({ port: 3000 });
app.get('/', (ctx) => {
    return { message: 'Hello' };
});
app.listen();

Middleware

Express:

app.use((req, res, next) => {
    console.log(req.method, req.path);
    next();
});

Shokupan:

app.use(async (ctx, next) => {
    console.log(ctx.method, ctx.path);
    return next();  // Must return!
});

Migration Checklist

• Replace req and res with ctx
• Change res.json() to return
• Remove express.json() middleware
• Return values from middleware
• Update header access: req.headers.key → ctx.headers.get('key')
• Update query params: req.query.key → ctx.query.get('key')

Next Steps

• Routing - Learn Shokupan patterns
• Controllers - Use decorators