How to make your Express app 9x faster (and type-safe)

npm i encore.dev

encore app init

{
   "compilerOptions": {
      "paths": {
         "~encore/*": [
            "./encore.gen/*"
         ]
      }
   }
}

import {Service} from "encore.dev/service";

export default new Service("my-service");

import { api, RawRequest, RawResponse } from "encore.dev/api";
import express, { request, response } from "express";

Object.setPrototypeOf(request, RawRequest.prototype);
Object.setPrototypeOf(response, RawResponse.prototype);

const app = express();

app.get('/foo', (req: any, res) => {
  res.send('Hello World!')
})

export const expressApp = api.raw(
  { expose: true, method: "*", path: "/!rest" },
  app,
);

import express, {Request, Response} from "express";

const app: Express = express();

// GET request with dynamic path parameter
app.get("/hello/:name", (req: Request, res: Response) => {
  const msg = `Hello ${req.params.name}!`;
  res.json({message: msg});
})

// GET request with query string parameter
app.get("/hello", (req: Request, res: Response) => {
  const msg = `Hello ${req.query.name}!`;
  res.json({message: msg});
});

// POST request example with JSON body
app.post("/order", (req: Request, res: Response) => {
  const price = req.body.price;
  const orderId = req.body.orderId;
  // Handle order logic
  res.json({message: "Order has been placed"});
});

import {api, Query} from "encore.dev/api";

// Dynamic path parameter :name
export const dynamicPathParamExample = api(
  {expose: true, method: "GET", path: "/hello/:name"},
  async ({name}: { name: string }): Promise<{ message: string }> => {
    const msg = `Hello ${name}!`;
    return {message: msg};
  },
);

interface RequestParams {
  // Encore will now automatically parse the query string parameter
  name?: Query<string>;
}

// Query string parameter ?name
export const queryStringExample = api(
  {expose: true, method: "GET", path: "/hello"},
  async ({name}: RequestParams): Promise<{ message: string }> => {
    const msg = `Hello ${name}!`;
    return {message: msg};
  },
);

interface OrderRequest {
  price: string;
  orderId: number;
}

// POST request example with JSON body
export const order = api(
  {expose: true, method: "POST", path: "/order"},
  async ({price, orderId}: OrderRequest): Promise<{ message: string }> => {
    // Handle order logic
    console.log(price, orderId)

    return {message: "Order has been placed"};
  },
);

// Raw endpoint
export const myRawEndpoint = api.raw(
  {expose: true, path: "/raw", method: "GET"},
  async (req, resp) => {
    resp.writeHead(200, {"Content-Type": "text/plain"});
    resp.end("Hello, raw world!");
  },
);

import express, {Request, Response} from "express";

const app: Express = express();

app.get("/save-post", async (req: Request, res: Response) => {
  try {
    // Calling another service using fetch
    const resp = await fetch("https://another-service/posts", {
      method: "POST",
      headers: {"Content-Type": "application/json"},
      body: JSON.stringify({
        title: req.query.title,
        content: req.query.content,
      }),
    });
    res.json(await resp.json());
  } catch (e) {
    res.status(500).json({error: "Could not save post"});
  }
});

import {api} from "encore.dev/api";
import {anotherService} from "~encore/clients";

export const microserviceCommunication = api(
  {expose: true, method: "GET", path: "/call"},
  async (): Promise<{ message: string }> => {
    // Calling the foo endpoint in anotherService
    const fooResponse = await anotherService.foo();

    const msg = `Data from another service ${fooResponse.data}!`;
    return {message: msg};
  },
);

import express, {NextFunction, Request, Response} from "express";

const app: Express = express();

// Auth middleware
function authMiddleware(req: Request, res: Response, next: NextFunction) {
  // TODO: Validate up auth token and verify that this is an authenticated user
  const isInvalidUser = req.headers["authorization"] === undefined;

  if (isInvalidUser) {
    res.status(401).json({error: "invalid request"});
  } else {
    next();
  }
}

// Endpoint that requires auth
app.get("/dashboard", authMiddleware, (_, res: Response) => {
  res.json({message: "Secret dashboard message"});
});

import { api, APIError, Gateway, Header } from "encore.dev/api";
import { authHandler } from "encore.dev/auth";
import { getAuthData } from "~encore/auth";

interface AuthParams {
  authorization: Header<"Authorization">;
}

// The function passed to authHandler will be called for all incoming API call that requires authentication.
export const myAuthHandler = authHandler(
  async (params: AuthParams): Promise<{ userID: string }> => {
    // TODO: Validate up auth token and verify that this is an authenticated user
    const isInvalidUser = params.authorization === undefined;

    if (isInvalidUser) {
      throw APIError.unauthenticated("Invalid user ID");
    }

    return { userID: "user123" };
  },
);

export const gateway = new Gateway({ authHandler: myAuthHandler });

// Auth endpoint example
export const dashboardEndpoint = api(
  // Setting auth to true will require the user to be authenticated
  { auth: true, method: "GET", path: "/dashboard" },
  async (): Promise<{ message: string; userID: string }> => {
    return {
      message: "Secret dashboard message",
      userID: getAuthData()!.userID,
    };
  },
);

import express, {NextFunction, Request, Response} from "express";
import {z, ZodError} from "zod";

const app: Express = express();

// Request validation middleware
function validateData(schemas: {
  body: z.ZodObject<any, any>;
  query: z.ZodObject<any, any>;
  headers: z.ZodObject<any, any>;
}) {
  return (req: Request, res: Response, next: NextFunction) => {
    try {
      // Validate headers
      schemas.headers.parse(req.headers);

      // Validate request body
      schemas.body.parse(req.body);

      // Validate query params
      schemas.query.parse(req.query);

      next();
    } catch (error) {
      if (error instanceof ZodError) {
        const errorMessages = error.errors.map((issue: any) => ({
          message: `${issue.path.join(".")} is ${issue.message}`,
        }));
        res.status(400).json({error: "Invalid data", details: errorMessages});
      } else {
        res.status(500).json({error: "Internal Server Error"});
      }
    }
  };
}

// Request body validation schemas
const bodySchema = z.object({
  someKey: z.string().optional(),
  someOtherKey: z.number().optional(),
  requiredKey: z.array(z.number()),
  nullableKey: z.number().nullable().optional(),
  multipleTypesKey: z.union([z.boolean(), z.number()]).optional(),
  enumKey: z.enum(["John", "Foo"]).optional(),
});

// Query string validation schemas
const queryStringSchema = z.object({
  name: z.string().optional(),
});

// Headers validation schemas
const headersSchema = z.object({
  "x-foo": z.string().optional(),
});

// Request validation example using Zod
app.post(
  "/validate",
  validateData({
    headers: headersSchema,
    body: bodySchema,
    query: queryStringSchema,
  }),
  (_: Request, res: Response) => {
    res.json({message: "Validation succeeded"});
  },
);

import {api, Header, Query} from "encore.dev/api";

enum EnumType {
  FOO = "foo",
  BAR = "bar",
}

// Encore.ts automatically validates the request schema and returns and error
// if the request does not match the schema.
interface RequestSchema {
  foo: Header<"x-foo">;
  name?: Query<string>;

  someKey?: string;
  someOtherKey?: number;
  requiredKey: number[];
  nullableKey?: number | null;
  multipleTypesKey?: boolean | number;
  enumKey?: EnumType;
}

// Validate a request
export const schema = api(
  {expose: true, method: "POST", path: "/validate"},
  (data: RequestSchema): { message: string } => {
    console.log(data);
    return {message: "Validation succeeded"};
  },
);

import express, {Request, Response} from "express";

const app: Express = express();

// Default error handler
app.get("/broken", (req, res) => {
  throw new Error("BROKEN"); // This will result in a 500 error
});

// Returning specific error code
app.get("/get-user", (req: Request, res: Response) => {
  const id = req.query.id || "";
  if (id.length !== 3) {
    res.status(400).json({error: "invalid id format"});
  }
  // TODO: Fetch something from the DB
  res.json({user: "Simon"});
});

import {api, APIError} from "encore.dev/api"; // Default error handler

// Default error handler
export const broken = api(
  {expose: true, method: "GET", path: "/broken"},
  async (): Promise<void> => {
    throw new Error("This is a broken endpoint"); // This will result in a 500 error
  },
);

// Returning specific error code
export const brokenWithErrorCode = api(
  {expose: true, method: "GET", path: "/broken/:id"},
  async ({id}: { id: string }): Promise<{ user: string }> => {
    if (id.length !== 3) {
      throw APIError.invalidArgument("invalid id format");
    }
    // TODO: Fetch something from the DB
    return {user: "Simon"};
  },
);

import express from "express";

const app: Express = express();

app.use("/assets", express.static("assets")); // Serve static files from the assets directory

import { api } from "encore.dev/api";

export const assets = api.static(
  { expose: true, path: "/assets/*path", dir: "./assets" },
);

import express, {Request, Response} from "express";

const app: Express = express();

app.set("view engine", "pug"); // Set view engine to Pug

// Template engine example. This will render the index.pug file in the views directory
app.get("/html", (_, res) => {
  res.render("index", {title: "Hey", message: "Hello there!"});
});

import {api} from "encore.dev/api";
import Handlebars from "handlebars";

const html = `
<!doctype html>
<html lang="en">
<head>
  <meta charset="UTF-8"/>
  <link rel="stylesheet" href="/assets/styles.css">
</head>
<body>
<h1>Hello {{name}}!</h1>
</body>
</html>
`;

// Making use of raw endpoints to serve dynamic templates.
// https://encore.dev/docs/ts/primitives/services-and-apis#raw-endpoints
export const serveHTML = api.raw(
  {expose: true, path: "/html", method: "GET"},
  async (req, resp) => {
    const template = Handlebars.compile(html);

    resp.setHeader("Content-Type", "text/html");
    resp.end(template({name: "Simon"}));
  },
);

import {describe, expect, test} from "vitest";
import request from "supertest";
import express from "express";
import getRequestExample from "../get-request-example";

/**
 * We need to add the supertest library to make fake HTTP requests to the Express.js app without having to
 * start the server. We also use the vitest library to write tests.
 */
describe("Express App", () => {
  const app = express();
  app.use("/", getRequestExample);

  test("should respond with a greeting message", async () => {
    const response = await request(app).get("/hello/John");
    expect(response.status).to.equal(200);
    expect(response.body).to.have.property("message");
    expect(response.body.message).to.equal("Hello John!");
  });
});

import {describe, expect, test} from "vitest";
import {dynamicPathParamExample} from "../get-request-example";

// This test suite demonstrates how to test an Encore route.
// Run tests using the `encore test` command.
describe("Encore app", () => {
  test("should respond with a greeting message", async () => {
    // You can call the Encore.ts endpoint directly in your tests,
    // just like any other function.
    const resp = await dynamicPathParamExample({name: "world"});
    expect(resp.message).toBe("Hello world!");
  });
});

import {api} from "encore.dev/api";
import {SQLDatabase} from "encore.dev/storage/sqldb";

// Define a database named 'users', using the database migrations in the "./migrations" folder.
// Encore automatically provisions, migrates, and connects to the database.
export const DB = new SQLDatabase("users", {
  migrations: "./migrations",
});

interface User {
  name: string;
  id: number;
}

// Get one User from DB
export const getUser = api(
  {expose: true, method: "GET", path: "/user/:id"},
  async ({id}: { id: number }): Promise<{ user: User | null }> => {
    const user = await DB.queryRow<User>`
        SELECT name
        FROM users
        WHERE id = ${id}
    `;

    return {user};
  },
);

// Add User from DB
export const addUser = api(
  { expose: true, method: "POST", path: "/user" },
  async ({ name }: { name: string }): Promise<void> => {
    await DB.exec`
        INSERT INTO users (name)
        VALUES (${name})
    `;
    return;
  },
);

CREATE TABLE users (
    id SERIAL PRIMARY KEY,
    name TEXT NOT NULL UNIQUE
);

import log from "encore.dev/log";

log.error(err, "something went terribly wrong!");
log.info("log message", { is_subscriber: true });