API Testing

API testing layout

API is a set of routines, protocols, and tools for building software applications. APIs specify how one software program should interact with other software programs.

In simple words, API stands for Application Programming Interface. API acts as an interface between two software applications and allows the two software applications to communicate with each other. API is a collection of software functions that can be executed by another software program

Examples of API Testing

A Google website can have API for various functions like search, translations, calendars, etc.

In general API’s are like below URL, they have the server name, paths.., etc

https://<server name>/v1/export/Publisher/Standard_Publisher_Report?format=csv

There are mainly 4 methods involve in API testing like the get, post, delete, and put methods.

GET- The GET method is used to extract information from the given server using a given URI. While using the GET request, it should only extract data and should have no other effect on the data.

POST- A POST request is used to create a new entity. It can also be used to send data to the server, for example, customer information, file upload, etc. using HTML forms.

PUT- Create a new entity or update an existing one.

DELETE- Removes all current representations of the target resource given by a URI.

How API Works

API testing requires an application to interact with API. to test an API, you require two things,

• Testing tool/framework to drive the API
• Writing down your own code to test the API

Steps for testing rest API

Step 1: Launch the application e.g Postman, once it is installed successfully

Application-Launch the application

Step 2: Enter the URL of the API in the URL textbox

Enter the URL

Step 3: Select the method for the type of HTTP method to hit- e.g. Post

API request-HTTP Method

Step 4: Provide parameters, authorizations, headers pre-requisite scripts, and texts by entering the key and value pair, token for authorization, and body in XML, raw, body, or GRAPHQL formats

Parameters

Now switch to Body Tab.

Set the required Body KEY AND VALUE e.G application/JSON

• Editor view: Raw input.
• Pass the request body of the API in the form of key-value pair e.g. {{“key1”:”value1",”key2":”value2"}. If it is post API, then we need to pass the body or parameters.

Database

Step 5: Next is to click on SEND

SEND

Response Details

API Response

Summary

•An API or Application Programming Interface is a set of programming instructions for accessing a web-based software application.

•There are mainly 4 methods involve in API testing like GET, POST, DELETE, PUT methods

•We need to check the response code, response message, and response body in API testing.