The HTTP Language

Posted on August 3, 2022 by rainbyte
Tags: api, http, request, vscode

It is typical to see the situation where a developer has to work with services which provide an HTTP api.

Suppose we are implementing the following common endpoints:

After using a particular programming language to achieve the task, it is possible that we would like to communicate with it to test it works fine.

There are many tools in the market which allows us to make requests, even in a graphical point and click way, but I have found more confortable to have a text representation.

There is a file format called HTTP language which can represent requests in an standardized fashion and it is supported by CLI tools like httpYac and editor extensions like vscode-restclient.

The httpYac tool can be installed using npm with the following command:

npm -g install httpyac

I wrote a few examples about how to make requests to the proposed HTTP api using the HTTP language format. It can be seen in the following snippet that the syntax is very simple and complies with IETF request line spec.

HTTP language examples

We can obtain a single Todo using the GET verb followed by the host and the port where server is running, the HTTP version is optional:

GET http://localhost:4000/todos HTTP/1.1

To create a new Todo task we can follow the example and use POST verb, and in this case the Content-Type header should be specified, given that we are attaching a JSON data structure as body of the request:

POST http://localhost:4000/todos HTTP/1.1
Content-Type: application/json

{
    "text": "blabla",
    "completed": false
}

If we want to obtain a single Todo task then a variable could be used to indicate the :id, and the value can be accessed using brackets:

@get-todo-id = a0804e5f-a849-4920-9023-557ecdd790d1
GET http://localhost:4000/todos/{{get-todo-id}} HTTP/1.1

To modify a Todo task we use the PUT verb as appears on the proposed API. It is important to have the Content-Type header defined as we use JSON:

@put-todo-id = a0804e5f-a849-4920-9023-557ecdd790d1
PUT http://localhost:4000/todos/{{put-todo-id}} HTTP/1.1
Content-Type: application/json

{
    "text": "foobar",
    "completed": false
}

The format can also be used with the DELETE verb, and in this case we use a variable one more time, but with different name to avoid conflicts:

@del-todo-id = a0804e5f-a849-4920-9023-557ecdd790d1
DELETE http://localhost:4000/todos/{{del-todo-id}} HTTP/1.1

These snippets can be copied to a file with .rest or .http extension, eg. todo-requests.http, and executed this way:

httpyac todo-requests.http

Happy hacking! 🐱

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