Postman is an Application Programming Interface (API) testing tool.
This instructional article provides a thorough perceptive on “Postman” and its outstanding features.
This article is intended to provide a platform for professionals working in the software testing domain who look to improving their knowledge of API testing.
Having a brief insight on how an API platform works is an essential part, to begin of this tutorial
Brief Introduction on Postman
Postman is an Application Programming Interface (API) testing tool. API is a communication path for a couple of applications thereby successfully establishing a connection between them.
Hence API is a package of functions, tools, and contracts which can be provided as an application to its users for achieving successful communication with other applications.
An API is needed whenever we need to access an application that involves Facebook, IG, or so on.
Postman was planned and implemented in the year 2012 by software developer and entrepreneur Abhinav Asthana to utilize API advances and testing. Postman is a designated tool for testing the software of an API.
It is mainly used for designing, documenting, verifying, creating, and making any alteration in APIs.
A process of distribution and surveillance of HTTP requests and responses is made easy with the postman and has been developed with a GUI which can perform well on platforms like Linux n Mac and Windows.
It is also designed to perform multiple HTTP responses and requests like – POST, GET PATCH...Also easily translating them into code
Key highlights - Necessity of a Postman
A postman API testing tool comes with a large user friendly base and is quiet popular because of the following reasons:
Its free of licensing option , hence its suitable to be used by any capacity of users
Easily downloadable
Ease of accessibility after downloading and installing
API calls can be used on various request and subfolders , hence maintenance is easy to suit various collections
Construction of various API calls like SOAP , REST and HTTP is reasonable
Can be varied to usage for test development by adding up of few check points based on HTTP response codes.
It can be included on an elaborate integration platform be it either continuous delivery or continuous deployment (CI/CD) channel
Repeated testing can be avoided using postman
It comes with a huge community support system
It is easier to conduct debugging test steps
Sharing files is made easy as export/import is made environment friendly
Functioning of Postman
To start working with postman, there are four sections you need to understand-:
Header
Response
Sidebar
Builder
Header: Postman comes with a New, Import, Runner bar which is used to perform and run tests with runner, Open New, Interceptor, Sync menus, etc.
It highlights the workspace which is an additional feature able to be shared with other team
This new menu bar is used to set up a new surrounding, collections and requests.
The Import menu bar is used to send the same
A file or a folder, link or a raw text can be imported from code depository option which is present under import option
A postman or a runner menu in the window is opened to open a new tab
Response: This section of postman contains only the response details
Sidebar
This section mainly consists of collectible such as maintain tests , folders , requests , sub folders , also data related to history i.e. all records of API request and API’s
Builder: This is the prominent section of a postman, it displays the current request name, untitled request is made if at all no title is mentioned
This section is also surround with (GET, POST, PUT, etc) and URL. A request is generally executed with a send button. A save button is used to make any modifications done to a request call.
Note: The Builder segment has tabs such as the Pre-requests menu, Authorization section, headers, a body part, parameters, settings, and testing.
Params tabs check the request in a key value able to be paired with a parameter request
The process of authorization of an API with its username, tokens, passwords, and others comes in an authorization tab
The body part and the header parts are predefined in the header and body tabs respectively
The test tabs are embedded in scripts that can run a request when it’s triggered, which makes confirmation if API is working well or not, also it checks if the acquired data and response code is accurate
Postman Environmental setup
On Operating systems such as Windows, Mac and Linux Postman can be installed- in the following ways:
1. Chrome Extension is a source by which postman can be installed
2. Standalone application is another way to use postman
Variable's in Postman Environment
The option of holding and repeating a parameter in the request, script, and collection section is provided by the variables, if there is a need to alter a value or a parameter, it should be done in one place.
Thus these variables help to reduce the chances of errors and thereby increasing the efficiency
A key-value pair is provided in a postman environment which helps to recognize each request separately and helps to produce diverse responses that come from the same request.
There can be multiple environments for multiple variables also a single key-values variable can be applied to a single variable.
To be precise a postman environment allows the implementation of requests and collections in a wide range of sets of data.
A sophisticated environment can be used to produce, test, and to develop certain parameters like URL, Password, and so on
Steps to Create a postman Environment
Follow the below mentioned steps to successfully work on postman environment:
Step 1 – proceed to the new menu and then press Environment.
Step 2 – How to supervise ENVIRONMENTS: pop-up gets unlocked and it opens. Environment name has to be entered... Then, add a variable name and value.
In this section we need to add variable u and its value
In the next step, close the pop-up.
Step 3 - The new Environment (ENV1) gets replicated, as a part of -No Environment dropdown.
Step 4 − Select the ENV1 environment by entering the call enter {{u}} in the address bar menu, we need to enclose it in double flower braces to utilize an environmental variable in a request
Step 5 − Then, press the “Send option”.
Instead of the actual URL this option can be used
This variable can be used instead of the actual URL.
Range of the Environmental variables
The Environmental variables are restricted within the environment in which it is created, it also means that it is opened to a larger scope area in its own environment and if it makes an attempt to select another environment for same variables it shows an error
Nonetheless, if we make use of the same Environment variable u from another Environment, says Environment Test, we will receive errors.
The screen shot below shows the error message, which arises if we use the same Environment variable u from a different environment −
Authorization processes related to postman
In postman platform, authorization is mainly done to verify the ability of a user to permit a resource place in the server...There many me place for multiple API’s in a project but the access to them can be constrained only to authorized users only.
Authorization process is applicable to API’s which is mandatory to be in a secured mode, this is done for identification and to make verification.
API testing of postman
After successful installation of postman, API testing process can be commenced by making HTTP requests to the server
HTTP processes
The Hypertext Transfer Protocol (HTTP) is progression to made set up a communiqué between servers and clients.
It mechanizes a request – response protocol between a client and a server. Here in this context a web browser is taken in to consideration as a client and it hosts the website- which is viewed as a server. The trendiest HTTP techniques are as follows:
GET: This method is applicable for recovery of data from a server through the mentioned URL
POST: This request to call is made to transfer data to the server
PUT: This call to action is used to update/create a response
PATCH: This is used to upgrade to fractional resources
HEAD: This works similar to GET; only change is that HEAD shall not have a response body
DELETE: This deletes the mentioned resources
Concluding remarks on postman
Postman is a Software testing tool mainly used for API testing. Testing an API is crucial before successful delivery of product since API’s are used for integration of freeware’s.
It chain of support system integration is initiated for the code development. It enhances every single method of the HTTP request, thereby providing a way to easily test the URL.
Certain advantages of Postman in API testing framework are:
Postman facilitates integration of test set up easily.
Postman makes it a way to save data for other tests.
Postman assists in better integration testing.
Postman integrates with other assembly tools like Jenkins, etc in a flawless way.
Postman makes an easy response to the association of various environments and tests to regulations made on repositories.
Postman is a freely available open-source tool which has its applications mainly by QA testers to priorities the ease of testing and reshaping the API testing platform. In context to achieving the required target results, thereby saving time and effort a postman tool has to be used properly and effectively
Comments