Postman使用手冊4——API test

一、Pre Request Scripts

Postman v0.10+ 版本支持pre-request scripts。

prerequest script.png

pre-request scripts是一個關聯了收藏夾內request，並且在發送request之前執行的代碼片段。這對於在request header中包含時間戳或者在URL參數中發送一個隨機字符串都是非常有用的。

例如：如果要在request的header中包含一個時間戳，你可以設置一個環境變量由一個函數返回他的值。

postman.setEnvironmentVariable('timestampHeader',new Date());

你可以在header中使 timestampHeader 變量，當request發送的時候，你的pre-request script將被執行，這個timestampHeader 變量的值將會替換{{timestampHeader}}。

注意：我們設置的環境對使用的環境變量必須是有效的。

二、Writing Tests

1.基本結構

---

![Uploading prerequest script_871640.png . . .]

Basic structure.png

Postman給了你一個環境讓你能夠為每個request編寫、執行你的test，而不用擔心任何額外的設置。

一個Postman的test本質上是JavaScript的代碼可以用來為一些特殊的test設置值。你可以在對象中設置一個描述性的鍵作為一個元素，然后聲明他如果是true或false。

tests[“Body contains user_id”] = responseBody.has(“user_id”)

這回核對body中是否包含了user_id這個字符串。如果你需要，你可以增加更多的鍵，這取決於你要用test做多少的事情。

test被保存為收藏夾request的一部分，這對於后端或前端的工程師來確保API運行的正常都是非常有意義的。

2.SNIPPETS

---

在寫test的時候這里有些事情需要注意，Postman嘗試使得列出常用的片段更簡單。你可以選擇你想添加的片段，然后適當的代碼將被添加到test的編輯器中。這是一個很好的方法來快速的構建test

3.查看結果

---

view result.png

Postman在你執行一個request的時候執行test，當然你可以選擇不考慮test。結果被顯示在一個tab里，並在頭部顯示多少test通過了測試。你設置在test中的變量將會被列在這里。如果值是true，這個test就會通過。你可以保持test tab活動直到你確保所有的test執行完。

三、Testing Sandbox

Postman的sandbox是一個JavaScript的執行環境，這使得你能夠為request寫pre-request scripts和test scripts 。不論你寫的代碼是pre-request scripts還是test script都會在sandbox中執行。

1.常用的庫和工具

---

• Lodash：
  JS utility library

• jQuery (Deprecated):
  Cross-platform JavaScript library. This will be removed in future versions of the sandbox.

• BackboneJS (Deprecated):
  Provides simple models, views, and collections. This will be removed in future versions of the sandbox.

• SugarJS:
  Extends native JS objects with useful methods

• tv4 JSON schema validator:
  Validates JSON objects against v4 of the json-schema draft

• CryptoJS:
  standard and secure cryptographic algorithms. Supported algorithms: AES, DES, EvpKDF, HMAC-MD5, HMAC-SHA1/3/256/512, MD5, PBKDF2, Rabbit, SHA1/3/224/256/512, TripleDES

• xml2Json(xmlString):
  This function behaves the same in Newman and Postman

• xmlToJson(xmlString)(Deprecated):
  This function does NOT behave the same in Newman and Postman

• postman.getResponseHeader(headerName) (Test-only):
  returns the response header with name "headerName", if it exists. Returns null if no such header exists. Note: According to W3C specifications, header names are case-insensitive. This method takes care of this.
  postman.getResponseHeader("Content-type") and postman.getResponseHeader("content-Type") will return the same value.

2.環境和全局變量

• postman.setEnvironmentVariable(variableName, variableValue) : Sets an environment variable "variableName", and assigns the string "variableValue" to it. You must have an environment selected for this method to work. Note: Only strings can be stored. Storing other types of data will result in unexpected behavior.

• postman.setGlobalVariable(variableName, variableValue):
  Sets a global variable "variableName", and assigns the string "variableValue" to it. Note: Only strings can be stored. Storing other types of data will result in unexpected behavior.

• postman.clearEnvironmentVariable(variableName):
  Clears the environment variable named "variableName". You must have an environment selected for this method to work.

• postman.clearGlobalVariable(variableName):
  Clears the global variable named "variableName".

• postman.clearEnvironmentVariables():
  Clears all environment variables. You must have an environment selected for this method to work.

• postman.clearGlobalVariables():
  Clears all global variables.

• environment:
  A dictionary of variables in the current environment. Use environment["foo"]
  to access the value of the "foo" environment variable.

• globals:
  A dictionary of global variables. Useglobals["bar"]
  to access the value of the "bar" global variable.

3.動態變量

Postman也有一些動態變量，你可以用在你的request中。這個現在主要還是在實現階段，更多的功能以后被被添加進來。注意：動態變量不可以用於SandBox中，你只能在request的URL、headers、body中以放在雙花括號中間的形式使用。

• {{$guid}}: Adds a v4 style guid

• {{$timestamp}}: Adds the current timestamp.

• {{$randomInt}}: Adds a random integer between 0 and 1000

4. Cookies

+ responseCookies {array} （Postman-only）:
Gets all cookies set for the domain. You will need to enable the Interceptor for this to work.

• postman.getResponseCookie(cookieName)（Postman-only）:
  Gets the response cookie with the given name. You will need to enable the interceptor for this to work. Check out the blog post.

5.Request/response相關屬性

• request {object}:
  Postman makes the request object available to you while writing scripts. This object is read-only. Changing properties of this object will have no effect. Note: Variables will NOT be resolved in the request object. The request object is composed of the following:

  • data {object}:
    this is a dictionary of form data for the request. (request.data["key"]=="value")

  • headers {object}:
    this is a dictionary of headers for the request (request.headers["key"]=="value")

  • method {string}:
    GET/POST/PUT etc.

  • url {string}:
    the url for the request.

• responseHeaders {object}(Test-only)(Deprecated):
  This is a map of the response headers. This is case-sensitive, and should not be used. Check thepostman.getResponseHeader()
  method listed above.

• responseBody {string}(Test-only):
  A string containing the raw response body text. You can use this as an input to JSON.parse, or xml2Json.

• responseTime {number}(Test-only):
  The response time in milliseconds

• responseCode {object}(Test-only):
  Contains three properties:

  • code {number}:
    The response code (200 for OK, 404 for Not Found etc)

  • name {string}:
    The status code text

  • detail {string}:
    An explanation of the response code

• tests {object}(Test-only):
  This object is for you to populate. Postman will treat each property of this object as a boolean test.

• iteration {number}:
  Only available in the Collection Runner and Newman. Represents the current test run index. Starts from 0.

(Test-only): This object is only available in the test script section. Using this in a pre-request script will throw an error.

四、Testing 實例

我們來看一些Postman用於test的例子。這些例子中的大多數在Postman中是有效的，他們像一行JavaScript語句一樣簡答。在你的request中你可以有很多的test。

注意：test腳本在從服務器收到response后執行

1.設置環境變量：

postman.setEnvironmentVariable("key", "value");

2.設置全局變量：

 postman.setGlobalVariable("key", "value");

3.檢查response的body中是否包含字符串：

tests["Body matches string"] = responseBody.has("string_you_want_to_search");

4.把XML的body轉換成JSON對象：

var jsonObject = xml2Json(responseBody);

5.檢查response的body是都為一個字符串：

tests["Body is correct"] = responseBody === "response_body_string";

6.檢查JSON的值：

1.  
   var data = JSON.parse(responseBody);
2.  
   tests["Your test name"] = data.value === 100;

7.內容類型存在（檢查不區分大小寫）

tests["Content-Type is present"] = postman.getResponseHeader("Content-Type"); //Note: the getResponseHeader() method returns the header value, if it exists.

8.內容類型存在（區分大小寫）：

tests["Content-Type is present"] = responseHeaders.hasOwnProperty("Content-Type");

9.response的響應時間小於200ms：

tests["Response time is less than 200ms"] = responseTime < 200;

10.狀態碼為200：

tests["Status code is 200"] = responseCode.code === 200;

11.Code name contains a string：

tests["Status code name has string"] = responseCode.name.has("Created");

12.成功的POST request狀態碼：

tests["Successful POST request"] = responseCode.code === 201 || responseCode.code === 202;

13.Use TinyValidator for JSON data

1.  
   var schema = {
2.  
   "items": {
3.  
   "type": "boolean"
4.  
   }
5.  
   };
6.  
   var data1 = [true, false];
7.  
   var data2 = [true, 123];
8.  
    
9.  
   console.log(tv4.error);
10.  
    tests["Valid Data1"] = tv4.validate(data1, schema);
11.  
    tests["Valid Data2"] = tv4.validate(data2, schema);

14.Sample data files

JSON files are composed of key/value pairs：

Download JSON file

For CSV files, the top row needs to contain variable names

Download CSV file