How to do API testing using Typicode json-server

In this example, we use the great json-server from Typicode to demonstrate the API testing functionality of Boozang.

Installing Typicode json server

Start by setting up an mock API by following the instructions here: https://github.com/typicode/json-server.

In brief, make sure to install NodeJS and use npm to install json-server globally.

npm install -g json-server

Create an empty data file “db.json” containing some JSON data i.e.

{
"posts": [
{ "id": 1, "title": "json-server", "author": "typicode" }
],
"comments": [
{ "id": 1, "body": "some comment", "postId": 1 }
],
"profile": { "name": "typicode" }
}

and start the mock API server locally

json-server --watch db.json

The server will be started on “http://localhost:3000”

Creating the API tests in Boozang

Now, go to “https://ai.boozang.com” (or https://eu.boozang.com” for Europe / Asia) and create a Boozang project called “API example” and add “http://localhost:3000” as application URL.

Now to get started we want to create the module “Posts” and create the following API tests

• Validate blog exists
• Add post
• Validate post
• Delete post
• Validate post doesn’t exist

We will later tie them together using a Cucumber test.

Overview of the API tests

Here is a brief overview of the API tests and things to keep in mind.

Validate blog available

Simple validation that check if blog is up and running

Add post

Adds a post using the REST API. Here we use the parameter

{
"author": "Mats Ljunggren",
"title": "A banana must rest"
}

Note: Remember to send this in the body of the POST request.

Validate post exists

Here we also use the parameter, but in this case we use a GET request to fetch the post and the script section to validate the post content

{
"author": "Mats Ljunggren",
"title": "A banana must rest"
}

Note how we use the parameter in the URL, and also in the validation section

vr = v[0].title===$parameter.title && v[0].author===$parameter.author;


We also save the post ID as project-level data

$project.currentId = v[0].id;

Delete post

The delete post simply uses the post id that was saved previously and deletes it using the DELETE operation.

Note: As you can see I add a validation to make sure $project.currentId is set.

Validate post doesn’t exist

A simple validation that the post is no longer there. As you can see from the validation section I make sure a status code 404 are being returned.

let vr = $result.status == 404;

The Cucumber test

Now it’s time to tie it all together using a Cucumber test. By going to the Features tab from the root, I create the following feature “Posts Management”, where I create the following scenario

Scenario Outline: Add and delete 

Given I have a blog with posts 
When I add a post with <title> and <author> 
Then the post with <author> and <title> should exist 
When I delete the post with <author> and <title> 
Then the post with <author> and <title> should not exist 

Examples: 
|author|title| 
|Mats Ljunggren|Some title| 
|Wensheng Li|Some other title|

This looks the following way in Boozang

After linking all the tests appropriately the test map looks as follows:

This was a very brief overview that only scratches the surface of what can be done in Boozang for API testing. For instance, this did not cover the following capabilities:

• Load testing
• Automated generation of API tests from regular tests
• Automated authorization token retrieval
• Auto-mapping of variables

We will try to cover these topics more substantially at some point in the near future. Let us know if you have any comments or suggestions!