Router (#12)

* add router

* add test for router

* export router in mod.ts

app.ts

@@ -2,6 +2,7 @@ import { serve, ServeInit } from "https://deno.land/std@0.163.0/http/server.ts";
 import { Context } from "./context.ts";
 import decode from "./decode.ts";
 import { Handler, ServerError } from "./types.ts";
+import { Router } from "./router.ts";
 
 const notFound = {
   status: 404,
@@ -88,5 +89,12 @@ export class WebApp {
     }
   };
 
+  use = (path: string, router: Router) => {
+    for (const [id, handler] of router.routes) {
+      const [method, pathname] = id.split(",");
+      this.#add(path + pathname, method, handler);
+    }
+  };
+
   serve = (opts?: ServeInit) => serve(this.handle, opts);
 }

mod.ts

@@ -2,3 +2,4 @@ import { WebApp } from "./app.ts";
 export default () => new WebApp();
 export { Context } from "./context.ts";
 export type { Handler } from "./types.ts";
+export { Router } from "./router.ts";

router.ts

@@ -0,0 +1,25 @@
+import { WebApp } from "./app.ts";
+import { Handler } from "./types.ts";
+
+export class Router extends WebApp {
+  routes: Map<string, Handler>;
+
+  constructor() {
+    super();
+    this.routes = new Map();
+
+    // deno-fmt-ignore-line
+    const methods = ['get', 'post', 'put', 'patch', 'delete', 'options', 'head'] as const;
+    for (const method of methods) {
+      this[method] = (path, handler) =>
+        this.#add(path, method.toUpperCase(), handler);
+    }
+  }
+
+  #add(pathname: string, method: string, handler: Handler) {
+    const id = method + ',' + pathname;
+    this.routes.set(id, handler);
+
+    return this;
+  }
+}

test.ts

@@ -1,12 +1,14 @@
 import { assertEquals } from "https://deno.land/std@0.161.0/testing/asserts.ts";
 import fast, { Context } from "./mod.ts";
+import { Router } from "./router.ts";
 
 function makeRequest(path: string, init: RequestInit = {}) {
   path = "https://example.com" + path;
   return new Request(path, { ...init });
 }
 
 const app = fast();
+const router = new Router();
 
 Deno.test("404", async () => {
   const req = makeRequest("/404");
@@ -130,3 +132,14 @@ Deno.test("decode", async () => {
   const res5 = await app.handle(req5);
   assertEquals(res5.status, 201);
 });
+
+router.get("/", () => "router home");
+app.use("/api", router);
+
+Deno.test("router", async () => {
+  const req = makeRequest("/api/");
+  const res = await app.handle(req);
+  const data = await res.text();
+  assertEquals(res.status, 200);
+  assertEquals(data, "router home");
+});