Request and response

There are several ways to send extra information as part of the request and response. These include:

Query params: parts of the url such as ?x=7&y=cool
URL params: dynamic parts of the endpoint, such as the 7 in /users/7
Headers: Meta information about the request or response which is part of the HTTP standard
Body: Complex, structured data which accompanies the request or response

HTTP tools

Tools such as cURL, Postman and the VS Code plugin Thunderclient allows us to construct more complex requests to test our applications. They simulate client applications such as CLIs, mobile apps and websites which would be making these requests in production.

Sending and receiving JSON

We can configure our app to send an receive JSON as part of the body. As a bonus, this will also encode and parse between JSON and Javascript without need of JSON.parse() and JSON.stringify().

const app = express()
app.use(express.json())

Now we can send and receive json

serverclient

app.get('/users', async (req, res) => {
  const users = await User.findAll()
  res.json(users)
})

bash

> GET /users HTTP/1.1
> Host: localhost:5000
> User-Agent: curl/7.81.0
> Accept: */*

< HTTP/1.1 200 OK
< X-Powered-By: Express
< Content-Type: application/json; charset=utf-8
< Content-Length: 465
< ETag: W/"1d1-ANZR8XoyXChze/h4JDQ5/asCB28"
< Date: Thu, 22 Feb 2024 17:07:31 GMT
< Connection: keep-alive
< Keep-Alive: timeout=5

[
  {
    "id": 1,
    "username": "EluskM",
    "verified": 1
  },
  {
    "id": 2,
    "username": "BillGatekeeper",
    "verified": 1
  },
  {
    "id": 3,
    "username": "JeffWho",
    "verified": 0
  },
  {
    "id": 4,
    "username": "OprahWindey",
    "verified": 1
  },
  {
    "id": 5,
    "username": "MarkZeeberg",
    "verified": 1
  },
  {
    "id": 6,
    "username": "LarryFlinger",
    "verified": 0
  },
  {
    "id": 7,
    "username": "CannyWest",
    "verified": 1
  },
  {
    "id": 8,
    "username": "TaylorSquid",
    "verified": 0
  },
  {
    "id": 9,
    "username": "ArianaVenti",
    "verified": 1
  },
  {
    "id": 10,
    "username": "KylieGenner",
    "verified": 0
  }
]

Request and response ​