Get To Know About API testing with Postman Tool

About Postman

Postman is a popular rest API client tool and it’s available as a Chrome browser extension but recently came out with native versions for both Mac and Windows. Postman is a robust, multi-featured application that helps you build, test, and share REST API calls easily and it is used for testing API web services.

For API validation, it has to verify you can do this when you receive the response. A common example of this is when you send a request to an API web service and get a response back, you verify that it returns an HTTP 200 OK status or it returns that the response contains a certain string in it.

Postman is the best choice for testing API rest services:

• Almost all modern web API data can be extracted by Postman.
• You can create a collection of REST API calls and save each call as part of a collection for execution in future.
• For transmitting and receiving REST information, Postman is more reliable
• Postman supports every HTTP method you can think of — including some you might even know about.

HTTP VERBS generally used in POSTMAN:

GET : Retrieve a specific resource (by an identifier).

HEAD : Works same as GET, just returns the header.

PUT : Update a specific record (by an identifier).

DELETE : Remove a specific record by an identifier.

POST : Create a new resource.

Steps for doing the API Testing using POSTMAN.

Step 1: Once you're up and running with Postman Tool

Step 2: Log-in with your Username and Password in Postman.

Step 3: Get the Request URL(Uniform Resource Locator) of the REst API web service and Paste that URL into the URL space given in the POSTMAN.

Step 4: Select the Method from the dropdown which you want to perform. For example GET,PUT,POST,DELETE.

(Note: The endpoint of the URL would be different for different Methods).

Step 5: Click Authorization and select Basic Auth (provide username and password only) from the Type dropdown.

Step 6: Once you've authenticated your request, Put the Headers with Key and Value field.

Step 7: Put the body part and select raw radio button option, In case you are using any POST/DELETE Method.

Step 8: Recheck the given URL and click on send button and observe the response in JSON format.