kauai

v1.0.6

Published

4 years ago

A simple HTTP server framework

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b2broker-manager

HTTP REST web framework

Kauai

A simple server framework (written in TypeScript).

Installation

npm install kauai

Usage

Kauai

.use() - Add a Middleware/Router to the stack

import { Kauai } from "kauai";

const app = new Kauai().use(middleware1).use(router2);
app.use("/path", middleware2, router2);
app.use(new RegExp("path"), router3, middleware1);

.off() - remove a Middleware/Router form the stack

import { Kauai } from "kauai";

const app = new Kauai()
  .use("/path", middleware1)
  .use(middleware2)
  .off("/path", middleware1);

.createServer() - create a server (HTTP)

import { Kauai } from "kauai";

const app = new Kauai()
  .use(new RegExp("path"), middleware)
  .use("/path2", router);
const server = app.createServer();

.createSecureServer() - create a server (HTTPS)

import { Kauai } from "kauai";

const app = new Kauai().use("/path", middleware).use("/path2", router);
const secureServer = app.createSecureServer({ key, cert });

Context

.log - get the logger (see @kauai/logger)

const { log } = context;
log.info("Hello World", { data: 100 });

.setHeader() - Set a response header

const name = "X-HEADER";
const value = ["value1", "value2"];
context.setHeader(name, value);

.status() - set the response status

context.status(401);

.request - get the original request object (instanceof KauaiRequest)

const { request } = context;

.response - get the original response object (instanceof KauaiResponse)

const { response } = context;

.id - get id of the context (generated by the randomUUID() function and logged as trace_id by the context.log)

const { id } = context;

.done

class MyMiddleware extends Middleware {
  public run(context: Context): void {
    context.done = true; // Stop passing the `context` to other middlewares
  }
}

.url - parsed URL object

const {
  log,
  url: { search },
} = context;
log.trace("url search string", { search });

.send() - execute context.response.send() and set context.done to true

await context.send(data);
// or
await context.response.send(data);
context.done = true;

.json() - execute context.response.json() and set context.done to true

const json = { message: "Hello World!" };
await context.json(json);
// or
await context.response.json(json);
context.done = true;

.text() - execute context.response.text() and set context.done to true

const text = "Hello World!";
await context.text(text);
// or
await context.response.text(text);
context.done = true;

.html() - execute context.response.html() and set context.done to true

const html = "<html></html>";
await context.html(html);
// or
await context.response.html(html);
context.done = true;

.form() - execute context.response.form() and set context.done to true

const form = new URLSearchParams({ a: "1" });
await context.form(form);
// or
await context.response.form(form);
context.done = true;

.sendFile() - execute context.response.sendFile() and set context.done to true

const path = "<path to file>";
await context.sendFile(path);
// or
await context.response.sendFile(path);
context.done = true;

.throw() - throw KauaiError

context.throw(402, { json: { error: "Payment Required" }, expose: true });

Middleware

Any middleware should be extended from the abstract Middleware class and implement the .run() method

import { randomInt } from "crypto";
import { Middleware, Context } from "kauai";

export class MyMiddleware extends Middleware {
  public async run(context: Context): Promise<void> {
    const randomNumber = await new Promise((resolve, reject) => {
      randomInt(1, 100, (error, n) => {
        if (error) {
          reject(error);
        } else {
          resolve(n);
        }
      });
    });

    if (randomNumber <= 50) {
      context.throw(400, {
        message: "Generated number is less than or equal to 50",
        expose: true,
      });
    }

    return context.json({ message: "Generated number is greater than 50" });
  }
}

.disabled - One can disable a middleware at any time

import { Middleware, Context } from "kauai";

export class MyMiddleware1 extends Middleware {
  public run(context: Context): Promise<void> {
    return context.json({ message: "Hello World" });
  }
}

const mm1 = new MyMiddleware1({ disabled: true });

export class MyMiddleware2 extends Middleware {
  public async run(): Promise<void> {
    // Disable `mm1` every hour
    setInterval(() => {
      mm1.disabled = !mm1.disabled;
    }, 1000 * 60 * 60);
  }
}

.ignore_errors - ignore errors from await this.run(context)

import { Middleware, Context } from "kauai";

export class MyMiddleware1 extends Middleware {
  public run(context: Context): Promise<void> {
    if (this.ignore_errors) {
      return context.json({ message: "Hello World" });
    }
    context.throw(400);
  }
}

const mm1 = new MyMiddleware1({ ignore_errors: true });

export class MyMiddleware2 extends Middleware {
  public async run(): Promise<void> {
    // Throw errors from `mm1.run()` every minute
    setInterval(() => {
      mm1.ignore_errors = !mm1.ignore_errors;
    }, 1000 * 60);
  }
}

KauaiError

KauaiError represents an HTTP error

import { Middleware, Context, KauaiError } from "kauai";

export class MyMiddleware extends Middleware {
  public run(context: Context): Promise<void> {
    const { length } = context.request.cookies;

    if (!length) {
      const status = 401;
      const expose = true;
      const message =
        "Text message to send (when `expose === true` and `json === null`)";
      const json = {
        error:
          "Send `json` as application/json (when `expose === true`) instead of `message`",
      };
      throw new KauaiError(status, { expose, message, json });
    }
    return context.json({ message: `Received ${length} cookies` });
  }
}

KauaiRequest

Simple usage with http

import { createServer } from "http";
import { KauaiRequest } from "kauai";
server = createServer({ IncomingMessage: KauaiRequest });

.header() - get a header by name

const rawHeader = request.header("X-Header");

.id - get the request id

const { id } = request;

.protocol - respects the Forwarded header:

const { protocol } = request;
if (protocol !== "https:") {
  console.error("The connection is not secure");
}

.secure - same as request.protocol === "https:"

const { secure } = request;
if (!secure) {
  console.error("The connection is not secure");
}

.query - A copy of URL.search parsed by the querystring.parse() method

const { query } = request;
// same as
const query = { ...parse(this.URL.search.substring(1)) };

KauaiResponse

Simple usage with http

import { createServer } from "http";
import { KauaiResponse } from "kauai";
server = createServer({ ServerResponse: KauaiResponse });

.cookies - The .send() method will add cookies to the response

import { randomUUID } from "crypto";
import { Cookie } from "kauai";

const key = "__Secure-Random-UUID";
const value = randomUUID();
const cookie = new Cookie({ key, value });
response.cookies.add(cookie);
await response.send("Check the `Set-Cookie` header for a random UUID");

.status() - Set the status code of the response

await response.status(400).send();

.set() - Set the headers

const headers = {
  "X-AMOUNT": "100.02 USD",
  "X-MONTHS": ["jan", "feb"],
};
await response.status(402).set(headers).send("Payment is required");

.send() - send data

await response.send(
  "Could be `number` | `string` | `Buffer` | `Readable` | `bigint` | `undefined`"
);

.json() - send an object as application/json using JSON.stringify()

const json = { k: "v", k1: 1, m: "message", f: false };
await response.json(json);

.text() - send text as plain/text

const text = "Hello World!";
await response.text(text);

.html() - send text as text/html

const html = "<html></html>";
await response.html(html);

.form() - send URLSearchParams;

const form = new URLSearchParams({ a: "1", b: ["a", "c"] });
await response.form(form);

.sendFile() - Send a file. Respects the following headers

const path = "<path to file>";
await response.sendFile(path);

Headers

Accept-Encoding

import { AcceptEncoding } from "kauai";

const encodings = AcceptEncoding.fromString(request.headers["accept-encoding"]);
// or using KauaiRequest
const { accept_encoding } = request;

Authorization

import { Authorization } from "kauai";

const authorization = AcceptEncoding.fromString(
  request.headers["Authorization"]
);
// or using KauaiRequest
const { authorization } = request;

Content-Encoding

import { ContentEncoding } from "kauai";

const encodings = ContentEncoding.fromString(
  request.headers["content-encoding"]
);
// or using KauaiRequest
const { content_encoding } = request;

Content-Range

import { ContentRange } from "kauai";

const cr = new ContentRange({ start: 0, end: 499, size: 1000 });
response.setHeader("Content-Range", cr.toString());

Content-Type

import { ContentType } from "kauai";

const type = ContentType.fromString(request.headers["content-type"]);
// or using KauaiRequest
const { content_type } = request;

import { Cookie } from "kauai";

const cookies = Cookie.fromString(request.headers["cookie"]);
// or using KauaiRequest
const { cookies } = request;
// or using KauaiResponse
const cookie1 = new Cookie({
  key: "__Secure-K1",
  value: "v1",
  http_only: false,
});
const cookie2 = new Cookie({
  key: "K2",
  value: "v2",
  same_site: "None",
  max_age: 1000,
});
response.cookies.add(cookie1).add(cookie2);

Forwarded

import { Forwarded } from "kauai";

const forwarded = Forwarded.fromString(request.headers["forwarded"]);
// or using KauaiRequest
const { forwarded } = request;

If-Modified-Since

import { IfModifiedSince } from "kauai";

const if_modified_since = IfModifiedSince.fromString(
  request.headers["if-modified-since"]
);
// or using KauaiRequest
const { if_modified_since } = request;

Range

import { Range } from "kauai";

const range = Range.fromString(request.headers.range);
// or using KauaiRequest
const { range } = request;

Test

npm run test:ci

Published

Vulnerabilities

Links

Maintainers

Keywords

Readme

Kauai

Installation

Usage

Kauai

Context

Middleware

KauaiError

KauaiRequest

KauaiResponse

Headers

Test