What is Postman

Postman is a platform for API

• Development

• Testing

• Management
  
  Step 1 - Goto Postman website https://www.postman.com/ | Create Account
  Check Email and verify account

  Step 2 - Login to Postman

  Step 3 - Explore GUI and features

  
  

Step 1 - Select the HTTP Method
Step 2 - Add the API endpoint
Step 3 - Add Headers, Authorizations etc as needed
Step 4 - For POST, PUT requests add Body
Step 5 - Save & Run, Check response

In web services, POST requests are used to send data to the API server to create or update a resource. The data sent to the server is stored in the request body of the HTTP request

It's worth noting that a POST request is non-idempotent
It mutates data on the backend server (by creating or updating a resource), as opposed to a GET request which does not change any data

Similar to POST, PUT requests are used to send data to the API to update or create a resource

The difference is that PUT requests are idempotent. That is, calling the same PUT request multiple times will always produce the same result

In contrast, calling a POST request repeatedly make have side effects of creating the same resource multiple times

Generally, when a PUT request creates a resource the server will respond with a 201 (Created), and if the request modifies existing resource the server will return a 200 (OK) or 204 (No Content)

A PATCH request is one of the lesser-known HTTP methods
The difference with PATCH is that you only apply partial modifications to the resource

The difference between PATCH and PUT, is that a PATCH request is non-idempotent (like a POST request)

To expand on partial modification, say you're API has a /users/{{userid}} endpoint, and a user has a username

With a PATCH request, you may only need to send the updated username in the request body - as opposed to POST and PUT which require the full user entity

As the name applies, DELETE APIs delete the resources (identified by the Request-URI)

DELETE operations are idempotent. If you DELETE a resource, it’s removed from the collection of resources

Some may argue that it makes the DELETE method non-idempotent It’s a matter of discussion and personal opinion

1. What is COLLECTION
2. How to create Collection
3. How to create folders inside collection
4. How to arrange requests inside collection

Collection is a group of API requests

Raghav Pal

Can create variables at the following levels (scope)

• Global

• Collection

• Environment

• Data

• Local

Priority

1. Local

2. Data

3. Env

4. Collection

5. Global

Set Variables with script

Global: pm.globals.set("name", "Edison");

Collection: pm.collectionVariables.set("name", "Newton");

Environment: pm.environment.set("name", "Rutherford");

Local: pm.variables.set("name", "Ramanujan");

Environment is a set of key-value pairs

Step 1 - Create an api request
Step 2 - Create environments and add key-value pairs (variables)

Step 3 - Refer the variables in request

Step 4 - Select the environment from dropdown and run request

Step 5 - Create more environments and execute request

Postman contains a powerful runtime based on Node.js that allows you to add dynamic behavior to requests and collections

You can add JavaScript code to execute during 2 events in the flow:

1. Before a request is sent to the server, as a pre-request script under the Pre-request Script tab.

2. After a response is received, as a test script under the Tests tab.

Postman will prompt you with suggestions as you enter text. Select one to autocomplete your

code

You can add pre-request and test scripts to a collection, a folder, a request within a collection, or a request not saved to a collection

Tests in Postman are JavaScript code that is executed after receiving response

Step 1 - Create a API request
Step 2 - Check the tests section under

Request
Collection
Folder

Step 3 - Create and run tests

Debugging scripts can be written under either the Pre-request Script tab or the Tests tab, with helpful messages logged in the Postman Console

The Postman Console logs the following information:

● The primary request that was sent, including all underlying request headers, variable values, and redirects

● The proxy configuration and certificates used for the request

● Network information such as IP addresses, ciphers, and protocols used

● Log statements and asynchronous requests from test or pre-request scripts

● The raw response sent by the server before it's processed by Postman