Development tools - script usage of network testing tool POSTMAN

POSTMAN is one of the most commonly used interface testing tools in network programming, capable of continuous automatic testing using scripts. This is based on the local application version.

References:

Postman interface automated testing

postman script application basics

Postman can use scripts to preprocess before sending requests, and use scripts to test after receiving responses.

Some of the testing process of the script can be viewed using a browser-like console, in the lower left corner of the application, or using the shortcut "Ctrl + Alt + C"

Set variables, get variable examples

After setting variables in a script, you can use these set variables in requests, for example:

1. Set an environment variable in the script, the variable name veriable_key, and the variable value areveriable_value

pm.environment.set("variable_key", "variable_value");

2. You can use the corresponding method to get the value of this variable and output the result on the console

console.log(pm.environment.get("variable_key"));

3. Click Send to view the results on the console

Methods for setting, getting, and clearing can be added using the links on the right

Use of environment variables

After setting the environment variables, they can be used in sending request settings. For example, there is an environment variable named pass:

In this way, you can use the environment variables to set parameters, request headers and other information in the request.

test

Pre-requests are processed before the request is sent, and testing occurs when the response is received. Whether the result of the test method pm.test()passes or not will be prompted in the test result in the response column.

Send request example

Test requests can be sent directly in the script

pm.sendRequest("https://postman-echo.com/get", function (err, response) {
    
    
    console.log(response.json());
});

The error information is in err, and the response information is response.

Commonly used variables and methods

You can add some commonly used fragments on the right side of the application. In addition, there are some variables and methods that can be used:

responseBody gets the response body content

responseBody is the content of the response packet, type is string. If it is json, you can use JSON.parse(responseBody)it to convert it into an object.

pm.response gets response information

pm.response is an attribute of the pm object, used to record some response information. If the response is json, you can use pm.response.json()to get it.

pm.expect() JSON inspection

pm.expect()The method is used to check json data, for example, check the value of numRaters of the first rating attribute in the book (array type) attribute of a json object, which is 51459:

let jsonData = pm.response.json();
// 测试检查 jsonData.book[0].rating.numRaters 属性的值
pm.expect(jsonData.book[0].rating.numRaters).to.eql(51459);

cheerio.load() is similar to jquery in operating html elements

When the response content is a page and the content_type is text/html, you can use this method to obtain each element in the page, and use a method similar to jquery to obtain the required data.

const $ = cheerio.load(pm.response.text())
console.log($('title').text())		// 获取 title 标签的文本内容
console.log($('#csrf').attr('value'))	// 获取标签的 value 属性值

In this way, the required data can be saved to environment variables for use.