Middlewares

In CrumbJS, middlewares work just like in Express or other express-like frameworks:
they are functions that run before one or more routes are executed.

You can register middlewares at two levels:

• Global level: When a middleware is added to the main App instance (in index.ts), it will be applied globally to all routes of your API.
• App level: When a middleware is added to a instance of App outside index.ts, it will be applied to all the routes contained on that App instance
• Route level: You can also attach middlewares to a specific route, so they will only run when that route is executed.

Create your first global Middleware

src/index.ts

const app = new App();
app.prefix("api");
app.use(cors({ origin: "*" }));
app.use(signals(true));
app.use(secureHeaders());
app.use(indexController);
// -----------------------------------
// this middleware will be executed before all api routes
app.use(async (ctx) => {
  console.log("Go ahead my friend!");
  return await ctx.next(); // Mandatory return in middlewares
});
// -----------------------------------
app.post(
  "/posts",
  async ({ body, setStatus }) => {
    setStatus(201);
    return body;
  },
  {
    type: "application/json",
    body: createPostSchema,
    summary: "Create a post",
    description:
      "Creates a blog post. If `slug` is omitted, it is generated from `title`.",
    tags: ["Posts"],
    operationId: "createPost",
  }
);

app.serve();

Call any endpoint and you will see on the console something like this

Create a route specific middleware

src/index.ts -> Conceptual example

import { Middleware } from "@crumbjs/core";

const middleware: Middleware = async ({ next }) => {
  console.log("Go ahead my friend!");
  return await next(); // Mandatory return in middlewares
};

const app = new App();
/** ... */
app.post(
  "/posts",
  async ({ body, setStatus }) => {
    setStatus(201);
    return body;
  },
  {
    use: middleware, // <-- that it! added to this specific route only.
    // You can also add more than one use: [ middleware1, middleware2 ]
    type: "application/json",
    body: createPostSchema,
    summary: "Create a post",
    description:
      "Creates a blog post. If `slug` is omitted, it is generated from `title`.",
    tags: ["Posts"],
    operationId: "createPost",
  }
);
/** ... */
app.serve();