Router Merging

TezX allows merging multiple routers into a parent app, enabling modular route management. This ensures:

Non-destructive merges — existing routes remain intact.
Hierarchical route structure — sub-routers can maintain their own nested routes.
Safe middleware scoping — each router can define its own middlewares.

Terminology

Term	Meaning
Parent Router	The main `TezX` instance or a Router that aggregates multiple sub-routers
Sub-Router	A router that contains its own routes & middleware
Merged Router	The result of merging sub-routers into the parent router

Pre-Merge Example

Parent router before adding any sub-router:

Parent Router:
├── /test
│   ├── GET → handler1
│   └── /1
│       ├── GET → handler2

Adding a Sub-Router

Sub-router structure:

Sub-Router:
├── /products
│   └── /2
│       ├── GET → handler3

After Merge

Merged router structure:

Merged Router:
├── /test
│   ├── GET → handler1
│   └── /1
│       ├── GET → handler2
├── /products
│   └── /2
│       ├── GET → handler3

All routes remain intact and merge non-destructively.

Code Example

import { TezX, Router } from "tezx";

// Parent router
const app = new TezX();
app.get("/test", (ctx) => ctx.text("Handler 1"));
app.get("/test/1", (ctx) => ctx.text("Handler 2"));

// Sub-router
const productRouter = new Router();
productRouter.get("/products/2", (ctx) => ctx.text("Handler 3"));

// Merge the routers into parent
app.use("/", productRouter);

Best Practices

1. Use Unique Prefixes

Prevent conflicts by using distinct prefixes:

const authRouter = new Router();
authRouter.get("/login", (ctx) => ctx.text("Login"));

app.use("/auth", authRouter);
// Resulting route: /auth/login

2. Middleware Hygiene

Each router can define its own middlewares:

const api = new Router();

api.use((ctx, next) => {
  ctx.setHeader("x-api", "v1");
  return next();
});

api.get("/status", (ctx) => ctx.json({ ok: true }));

app.use("/api", api);

Requests to /api/status automatically pass through the API middleware.

3. Inspect Route Tree

Logging can help debug route structure:

console.log(app.routes);
// Outputs a tree-like structure for verification

4. Safe Re-Merge Patterns

Avoid defining the same path across multiple routers:

// ❌ Avoid
router1.get("/ping", ...);
router2.get("/ping", ...);

// ✅ Use prefixes
app.use("/api", router1);
app.use("/public", router2);

Router Merging

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