How to Write & Add Tests Scripts with Postman? – Devstringx

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How to Write & Add Tests Scripts with Postman? – Devstringx

What Is Postman?

Postman is an API (Application programming interface) development tool that helps to build, test, and modify APIs. Virtually any practicality that might require by any developer encapsulate in this tool. It’s the power to make varied sorts of protocol requests(GET, POST, PUT, PATCH), save the environment for later use, and change the API code for various languages(like JavaScript, and Python).

How to Write Tests on Postman?

Tests ensure that your API is functioning as expected, that integrations between services are functioning reliably, and that any changes haven’t broken existing functionality. You can take a look at scripts on your Postman API requests in JavaScript. You also can take a look at code to resource the debugging technique while something is going wrong together with your API project. For example, you could possibly write a take a look to validate your API’s blunders managed via means of sending a request with incomplete information or incorrect parameters.

Adding Tests

You’ll add tests to individual requests, collections, and folders in every collection. postman includes code snippets you add and so amend to fit your test logic. To feature tests to a request, open the request and enter your code within the take a look at tab. Tests can execute once the request runs. The output is in the response’ Test Results tab.

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Adding Test gRPC Request

  1. Move to the Scripts tab in your gRPC request.
  2. Choose the execution hook (Before invoking or once response) to which you would like to feature a test.
  3. Use snippets from the proper pane to add a test or write tailored assertions.

Each execution hook offer for all gRPC requests no matter the tactic kind being unary, shopper streaming, server streaming, or biface streaming. Your scripts will embody but several tests you wish and can save beside the remainder of your request after you select Save.

Tests are run after you select Invoke, either before or once the request invokes. If you decide on Cancel, the request execution and to any extent further script execution.

Test Scripts

Test scripts will use dynamic variables, do test assertions on response information, and pass data between requests. within the tests tab for a request, enter your JavaScript manually or choose Snippets next to the code editor.

Tests execute once the response is received. Once you select Send, postman runs your test script after the response data returns from the API.

Validating Response

To validate the info that came back by a request, you’ll use the pm.response object during a test. outline tests using the pm.test function, providing a name and performance that returns a Boolean (true or false) value indicating if the test passed or in your assertions to check the response detail.

➔    pm.test():

The pm.test() characteristic uses to write down check specs within the Postman check sandbox. Writing tests inner this characteristic lets you name the check accurately and ensures that the relaxation of the script isn’t always blocked in case of any errors.

Image of Postman check sandbox

➔    pm.expect():

The pm.expect() statement characteristic becomes constructed at the shoulders of the famous JavaScript test library chaiJS BDD. Using a comparable syntax, pm.expect() makes it clean to put in writing readable tests, and you could address assertions of facts from a reaction or variables.

image of JavaScript test library


The The item provides a shorthand for often-used response-based checks. the exploitation of this family of assertions streamlines tests for response standing sorts and body variations.

Image of shorthand exploitation

Test Results

After you run a request with tests, move to the Tests tab within the response viewer. you’ll see a listing of your tests and whether or not the test has passed or failed. A Boolean that evaluates to true could be a passing test, and a boolean that evaluates to false is a failing test.

Image of Test Results of Postman

If you are interested in even more software testing-related articles and information from us here at Devstringx, then we have a lot to choose from for you.


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