keq v2.3.2

Keq is a request API write by Typescript for flexibility, readability, and a low learning curve. It also works with Node.js! Keq wraps the Fetch APIs, adding chain calls and middleware functions.

Usage

Send Request

A request can be initiated by invoking the appropriate method on the request object, then calling .then() (or .end() or await) to send the request. For example a simple GET request:

import { request } from "keq";

const body = await request
  .get("/search")
  .set("X-Origin-Host", "https://example.com")
  .query("key1", "value1");

Request can be initiated by:

import { request } from "keq";

const body = await request({
  url: "/search",
  method: "get",
});

Absolute URLs can be used. In web browsers absolute URLs work only if the server implements CORS.

import { request } from "keq";

const body = await request.get("https://example.com/search");

DELETE, HEAD, PATCH, POST, and PUT requests can also be used, simply change the method name:

import { request } from "keq";

await request.head("https://example.com/search");
await request.patch("https://example.com/search");
await request.post("https://example.com/search");
await request.put("https://example.com/search");
await request.delete("https://example.com/search");
await request.del("https://example.com/search");

.del() is the alias of .delete().

Keq will parse body according to the Content-Type of Response and return undefined if Content-Type not found. Add invoke .resolveWith('response') to get the origin Response Object.

import { request } from "keq";

const response = await request
  .get("http://test.com")
  .resolve('response')

const body = await response.json();

We will introduce resolveWith in more detail later.

Keq won't auto parse body, if response.status is 204. The HTTP 204 No Content success status response code indicates that server has fulfilled the request but does not need to return an entity-body, and might want to return updated meta information

Setting header fields

Setting header fields is simple, invoke .set() with a field name and value:

import { request } from "keq";

await request
  .get("/search")
  .set("X-Origin-Host", "https://example.com")
  .set("Accept", "application/json");

You may also pass an object or Headers to set several fields in a single call:

import { request } from "keq";

await request
  .get("/search")
  .set({
    "X-Origin-Host": "https://example.com",
    Accept: "application/json",
  });

Request query

The .query() method accepts objects, which when used with the GET method will form a query-string. The following will produce the path /search?query=Manny&range=1..5&order=desc.

import { request } from "keq";

await request
  .get("/search")
  .query({ query: "Manny" })
  .query({ range: "1..5" })
  .query("order", "desc");

Or as a single object:

import { request } from "keq";

await request
  .get("/search")
  .query({ query: "Manny", range: "1..5", order: "desc" });

Request routing parameters

The .params() method accepts key and value, which when used for the request with routing parameters.

import { request } from "keq";

await request
  // request to /users/jack/books/kafka
  .get("/users/:userName/books/{bookName}")
  .params("userName", 'jack');
  .params("bookName", "kafka");
  // or invoke with an object
  .params({
    "userName": "jack",
    "bookName": "kafka"
  })

JSON Request

A typical JSON POST request might look a little like the following, where we set the Content-Type header field appropriately:

import { request } from "keq";

await request
  .post("/user")
  .set("Content-Type", "application/json")
  .send({ name: "tj", pet: "tobi" });

When passed an object to .send(), it will auto set Content-Type to application/json

x-www-form-urlencoded Request

A typical Form POST request might look a little like the following:

import { request } from "keq";

await request
  .post("/user")
  .type("form")
  .send({ name: "tj", pet: "tobi" })
  .send("pet=tobi");

To send the data as application/x-www-form-urlencoded simply invoke .type() with "form". When passed an string to .send(), it will auto set Content-Type to application/x-www-form-urlencoded.

When calling .send () multiple times, the value of Content-Type will only be set when the first calling .send ().

Form-Data Request

A typical Form POST request might look a little like the following:

import { request } from "keq";

const form = new FormData();
form.append("name", "tj");
form.append("pet", "tobi");

// prettier-ignore
await request
  .post("/user")
  .type("form-data")
  .send(form)

When passed an FormData object to .send(), it will auto set Content-Type to multipart/form-data.

You can append field by invoke .field() and .attach()

import { request } from "keq";

await request
  .post("/user")
  .field("name", "tj")
  .field("pet", "tobi")
  .attach("file", new Blob(["I am tj"]));

Setting the Content-Type

The obvious solution is to use the .set() method:

import { request } from "keq";

// prettier-ignore
await request
  .post("/user")
  .set("Content-Type", "application/json")

As a short-hand the .type() method is also available, accepting the canonicalized MIME type name complete with type/subtype, or simply the extension name such as "xml", "json", "png", etc:

import { request } from "keq";

await request
  .post("/user")
  .type("json");

resolve responseBody

It was mentioned before that Keq will automatically parses the response body. And we can control the parsing behavior by calling .resolveWith(method). There are multiple parsing methods for us to choose from

Request Retry

No retry by default, invoke .retry(retryTimes[, retryDelay[, retryOn]]) to set retry parameters

import { request } from "keq";

await request
  .get("http://test.com")
  .retry(2, 1000, (attempt, err, ctx) => {
    if (err) {
      console.log("an error throw");
      return true;
    }

    return false;
  });

Set Request Redirect mode

Follow redirect by default, invoke .redirect(mode) to set the redirect mode. Allow values are "error", "manual" and "follow".

import { request } from "keq";

await request
  .get("http://test.com")
  .redirect("manual");

Set Request Credentials And Mode

These two parameters are used to control cross-domain requests.

import { request } from "keq";

await request
  .get("http://test.com")
  .mode("cors")
  .credentials("include");

Keq Internal Options

Invoke .option() add options.

import { request } from "keq";

const response = await request
  .get("http://test.com")
  .option("middlewareOption", "value");

Or as a single object:

import { request } from "keq";

await request
  .get("http://test.com")
  .options({
    middlewareOption: "value",
  });

​

Timeout

Keq has built-in timeout function.

await request
  .get("http://test.com")
  // 5000 milliseconds
  .timeout(5000)

Flow Control

Controlling the behavior of sending requests multiple times.

Abort

If the previous request was not completed, abort the last request.

import { request } from "keq";

request
  .get("http://test.com/cat")
  // second args is the abort signal
  // this will abort the request with same signal
  // a unique signal will be generated, if not signal set.
  .followControl("abort", 'animal');
  .end()

request
  .get("http://test.com/dog")
  // abort http://test.com/cat
  .followControl("abort", 'animal')
  .end()

Serial

The next request will not start until the previous request is completed.

import { request } from "keq";

request
  .get("http://test.com/cat")
  // a unique signal will be generated, if signal is not set.
  .followControl("serial", 'animal');
  .end()

// This request will be send after https://test.com/cat is complete
request
  .get("http://test.com/dog")
  .followControl("serial", 'animal')
  .end()

Middleware

You can extend Keq by write/import middleware. A typical middleware might look a little like the following:

import { request } from "keq"

const middleware = async (context, next) => {
  // equal to .retry(2)
  context.options.retryTimes = 2

  await next()
  const response = context.response
  if (!response) return
  const body = await response.json()

  // custom keq return type
  context.output = JSON.stringify(body)
}

// Global Middleware
request
  .use(middleware)

request
  .useRouter()
  /**
   * the middleware run when request url host is "example.com"
   */
  .host("example.com", middleware)
  /**
   * the middleware run when request url is location
   * It is usefully in browser.
   */
  .location(middleware)
  /**
   * the middleware run when pathname match `/api/service_name/**`.
   */
  .pathname("/api/service_name/**" middleware)
  /**
   * the middleware run when method is GET
   */
  .method('get', middleware)
  /**
   * used with keq-cli
   */
  .module('yourServiceName',middleware)
  /**
   * this middleware run when pathname start with '/api'
   */
  .route((ctx) => ctx.pathname.startsWith('/api'), middleware)

await request
  .get("http://test.com")
  /**
   * the middleware run once
   */
  .use(middleware)

request.use(middleware)

Add an global middleware, The running order of middleware is related to the order of .use()

request.useRouter()

Middleware Router

write an middleware

Middleware should be an asnyc-function that accept two argument:

Keq's context object has many parameters. The following lists all the built-in context attributes of Keq:

.useRouter()

This is the utils used to route middleware.

Create Request

If you want to create a request instance, you can invoke request.create():

import { createRequest } from "keq";

const customRequest = createRequest();

// Middleware only takes effect on customRequests
customRequest.use(/** some middleware */);

const body = await customRequest.get("http://test.com");

The gloabl request instance is created by request.create() too.

Q&A

The diffirent between .then() and .end()

Both .then () and .end () will send a request and return a Promise object. The difference between the two is that when called multiple times.

.then () actually sends only one request, no matter how many times it is called.

.end () will send a request for each call.

import { request } from "keq";

const keq = request.get("http://test.com");

keq.then(onfulfilled, onrejected);
// Won't send request, and will use the last request result.
keq.then(onfulfilled, onrejected);

keq.end();
keq.end();

The diffirent between ctx.res and ctx.response

ctx.response will allways return a new Response created by ctx.res && ctx.res.clone(). Sothat each middleware could calling ctx.response.json(), ctx.response.text(), ctx.response.formData().

What's more, The .formData() function isn't existed in Response returned by node-fetch. keq will append it to Response after clone, if in NodeJS.

See More

Keq is inspired by SuperAgent and Koa.

• Superagent
• Koa

Contributing & Development

If there is any doubt, it is very welcome to discuss the issue together.