About the basics of the API, Rest API for a beginner tester. Which query is faster? 2023

If you are a beginner tester, then knowing the API can be useful for you, as API testing can help you catch bugs and improve the quality of your application.

Next you will learn about:

API

API (Application Programming Interface) is a set of instructions and protocols that allow programs to interact with each other. APIs are used to exchange data between different applications, web services and servers.

Below are the API basics to help you get started with API testing:

1. Check out the API documentation: each API usually has documentation that describes the available methods and parameters, as well as sample requests and responses. This documentation will help you understand how to use the API and what data can be retrieved.

2. Use API testing tools: There are many API testing tools such as Postman, SoapUI, Swagger, etc. They allow you to send requests to the API and view the responses. Using these tools will help you quickly test the API and check if it works.

3. Testing API Methods: API methods are actions that you can perform using the API, such as getting a list of products, creating a new order, or updating user data. When testing API methods, you need to verify that they work correctly, return correct data, and handle errors.

4. Checking data formats: The API can return data in various formats such as JSON, XML, or CSV. When testing an API, you need to check that the data is returned in the correct format and conforms to the expected structure.

5. Error processing: when using the API, errors are possible, such as an invalid request or missing data. When testing an API, you need to verify that errors are handled correctly and correct error messages are returned.

6. API Test Automation: API testing automation allows you to quickly and efficiently test APIs, especially with a large number of methods and parameters. To automate API testing, you can use programming languages ​​such as Python, Java, or JavaScript, or test automation tools such as Postman or SoapUI.

REST API

REST API (Representational State Transfer Application Programming Interface) is an architecture standard for creating web services that can be called by clients using the HTTP protocol. RESTful API uses HTTP methods (GET, POST, PUT, DELETE) to work with resources and provides data in JSON or XML format.

Basic principles of REST API:

1. Each resource has a unique URI (Uniform Resource Identifier).

2. The client sends requests to the server using HTTP methods (GET, POST, PUT, DELETE) to get or modify a resource.

3. The server returns responses in JSON or XML format, depending on the request.

4. The REST API does not store session state on the server between requests. Each request is a separate request to the server.

5. The REST API uses caching to reduce server load.

REST API testing is an important part of web application testing and can be done using various tools such as Postman, SoapUI, JMeter and more.

Request examples:

1. GET request. Used to receive information from the server. For example, an API request to get a list of all users in JSON format: GET https://api.example.com/users

2. POST requests used to send data to the server. For example, an API request to create a new user: POST https://api.example.com/users

   {

       "name": "John Doe",

       "email": "john.doe@example.com",

       "password": "password123"

   }

3. PUT requests used to update data on the server. For example, an API request to update information about a user with id 123: PUT https://api.example.com/users/123

   {

       "name": "Jane Doe",

       "email": "jane.doe@example.com",

       "password": "newpassword123"

   }

4. DELETE requests used to delete data on the server. For example, an API request to delete a user with id 123: DELETE https://api.example.com/users/123

5. Query parameters allow you to pass additional parameters in the request. For example, an API request to get a list of users sorted alphabetically by name: GET https://api.example.com/users?sort=name

6. path parameters are used to pass variables in the URL. For example, a request to the API to get information about the user with id 123: GET https://api.example.com/users/123

7. header parameters allow you to pass additional parameters in the request header. For example, a request to the API to pass an authorization token: GET https://api.example.com/users

   Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c

Which query is faster?

The question of which request is faster in an API depends on the specific situation and API configuration. However, in general, HTTP GET requests are generally faster than HTTP POST, PUT, and DELETE requests.

This is because GET requests do not require data to be passed in the request body, which can take extra time, especially when transferring large amounts of data. GET requests can also be cached, which can speed up their execution.

However, if the API uses nested queries or queries with parameters, then POST requests can be faster because they allow you to pass complex parameters and data in the request body.

In addition, the request speed also depends on factors such as network speed, server load, and API code optimization. Therefore, it is important to perform API performance testing and choose the best query methods in each specific situation.