Acceptance Test Robot Framework: Test returned JSON by Rest API
API testing is one of common jobs in automation tests, especially when multiple teams work on different parts of a system and use API as the mean of communication between components.
We will examine how Robot Framework can help us to test the API, let’s say REST API that return JSON results.
To access REST API, we need to use a HTTP Library. Standard Libriries from Robot Framework does not include this, so we need to manually into this addon.
pip install --upgrade robotframework-httplibrary
Then, let’s get started to test our API!
Wait, where is our API to test? We don’t have one, but luckily enough, there is free service to build sample APIs that we can use apiary.io, it is a great tool to mock API calls, i.e. you can trap the call requests and return any dummy data you want without writing any real logic. In short, no coding required!
Just register then it gives us a default API sample that we can use in our test immediately:
//http://private-2012e-nguyenthethang.apiary-mock.com/questions?page=1
[
{
"published_at":"2015-07-10T05:49:29.577344+00:00",
"choices":[
{
"url":"/questions/62/choices/265",
"votes":0,
"choice":"Android"
},
{
"url":"/questions/62/choices/264",
"votes":0,
"choice":"Bot"
},
{
"url":"/questions/62/choices/266",
"votes":0,
"choice":"God"
},
{
"url":"/questions/62/choices/263",
"votes":0,
"choice":"Human"
}
],
"url":"/questions/62",
"question":"Who Are You?"
},
...
]
Let’s create our test file api.robot. We start by importing the library and make the very first test: make sure our request will return a successful status (status=200)
*** Settings ***
Documentation Test our very first REST API
Library HttpLibrary.HTTP
*** Variables ***
${API_ENDPOINT} http://private-2012e-nguyenthethang.apiary-mock.com
*** Test Cases ***
List Question Request Should Return Successful
GET ${API_ENDPOINT}/questions
Response Status Code Should Equal 200
Now, run our console to check result:
pybot api.robot ============================================================================== Api :: Test our very first REST API ============================================================================== List Question Request Should Return Successful | PASS | ------------------------------------------------------------------------------ Api :: Test our very first REST API | PASS | 1 critical test, 1 passed, 0 failed 1 test total, 1 passed, 0 failed ============================================================================== Output: /Users/justin/robotframework/APITest/output.xml Log: /Users/justin/robotframework/APITest/log.html Report: /Users/justin/robotframework/APITest/report.html
Next, we will write some tests to verify the content of the API response. Let’s check if the response contains the correct number of items (1 item in the mock data, we can create more if we want). It takes several steps to do so:
- Grab the response result
- Convert it into JSON
- Examine the JSON object
Here is our test content:
List Question Requset Should Return Correct Number Of Items
GET ${API_ENDPOINT}/questions
${result} = Get Response Body
${json} = Parse Json ${result}
Length Should Be ${json} 10
That’s good. Our tests pass beautifully. But we should refactor it a little bit so that it looks nicer and descriptive enough.
*** Settings ***
Documentation Test our very first REST API
Library HttpLibrary.HTTP
*** Variables ***
${API_ENDPOINT} http://private-2012e-nguyenthethang.apiary-mock.com
*** Test Cases ***
List Question Request Should Return Successful
Get Question list
Response Status Code Should Equal 200
List Question Requset Should Return Correct Number Of Items
Get Question list
${json} = Parse Response Body To Json
Length Should Be ${json} 10
*** Keywords ***
Get Question list
GET ${API_ENDPOINT}/questions
Parse Response Body To Json
${result} = Get Response Body
${json} = Parse Json ${result}
[Return] ${json}
So we have DRYed it a bit and know that a keyword can return data. Next, let’s try to make a POST request, it is also a very common case.
You can find an API to create question at apiary editor, according to it, we need to send following JSON data to server:
{
"question": "Favourite programming language?",
"choices": [
"Swift",
"Python",
"Objective-C",
"Ruby"
]
}
This API will return the created question detail as response, so we not only test if it is 200, but also double check the result.
*** Settings ***
Documentation Test our very first REST API
Library HttpLibrary.HTTP
*** Variables ***
${API_ENDPOINT} http://private-2012e-nguyenthethang.apiary-mock.com
${QUESTION_JSON_DATA} { "question": "Favourite programming language?", "choices": [ "Swift", "Python", "Objective-C", "Ruby" ] }
*** Test Cases ***
Create Question Should Return Success
Create Http Context private-2012e-nguyenthethang.apiary-mock.com http
Set Request Header Content-Type application/json
Set Request Body ${QUESTION_JSON_DATA}
POST /questions
Response Status Code Should Equal 200
Code is self-explanatory: we set the necessary headers and body and send it, it would return desired 200 status. We want to compare the returned result with our expected result, particular this response:
{
"question": "Favourite programming language?",
"published_at": "2014-11-11T08:40:51.620Z",
"url": "/questions/2",
"choices": [
{
"choice": "Swift",
"url": "/questions/2/choices/1",
"votes": 0
}, {
"choice": "Python",
"url": "/questions/2/choices/2",
"votes": 0
}, {
"choice": "Objective-C",
"url": "/questions/2/choices/3",
"votes": 0
}, {
"choice": "Ruby",
"url": "/questions/2/choices/4",
"votes": 0
}
]
}
But this content is rather long, if we put it in our test file, it would be a little bit messy, therefore we will put it into an external file and read it into our test case. To do that, we import the library OperatingSystem from Standard Libraries.
*** Settings ***
Documentation Test our very first REST API
Library HttpLibrary.HTTP
Library OperatingSystem
*** Test Cases ***
Create Question Should Return Success
Create Http Context private-2012e-nguyenthethang.apiary-mock.com http
Set Request Header Content-Type application/json
Set Request Body ${QUESTION_JSON_DATA}
POST /questions
Response Status Code Should Equal 200
${result} = Parse Response Body To Json
${expectation} = Parse Json From File
Should Be Equal ${result} ${expectation}
*** Keywords ***
Parse Json From File
${file} = Get File question_detail.json
${json} = Parse Json ${file}
[Return] ${json}
Note that Apiary supports multiple mode, in Production mode, your requests can change data on server. So far we should always use Mock Server mode, so that it returns what we config it to be. Otherwise the test case maybe much more complex than the scope of this post. Such as primary key value and timestamp values always change and difficult to test.
You may notice that we parse Json into objects and compare them. It is pretty difficult to compare 2 json objects somehow.
In the end, we have done our important test cases, let’s refactor the code so that it looks tidier.
*** Settings ***
Documentation Test our very first REST API
Library HttpLibrary.HTTP
Library OperatingSystem
Test Setup Create API Context
*** Variables ***
${API_ENDPOINT} http://private-2012e-nguyenthethang.apiary-mock.com
${QUESTION_JSON_DATA} { "question": "Favourite programming language?", "choices": [ "Swift", "Python", "Objective-C", "Ruby" ] }
*** Test Cases ***
List Question Request Should Return Successful
Get Question list
Response Status Code Should Equal 200
List Question Requset Should Return Correct Number Of Items
Get Question list
Question List Should Have Correct Length
Create Question Should Return Success
Make Question Creation Request
Response Status Code Should Equal 201
Created Question Details Should Be Correct
*** Keywords ***
Create API Context
Create Http Context private-2012e-nguyenthethang.apiary-mock.com http
Make Question Creation Request
Set Request Header Content-Type application/json
Set Request Body ${QUESTION_JSON_DATA}
POST /questions
Question List Should Have Correct Length
${json} = Parse Response Body To Json
Length Should Be ${json} 1
Created Question Details Should Be Correct
${result} = Parse Response Body To Json
${expectation} = Parse Json From File
Should Be Equal ${result} ${expectation}
Get Question list
GET /questions
Parse Json From File
${file} = Get File question_detail.json
${json} = Parse Json ${file}
[Return] ${json}
Parse Response Body To Json
${result} = Get Response Body
Log ${result}
${json} = Parse Json ${result}
[Return] ${json}
By moving the techinical details into keywords we make our test cases more decriptive as natural languages. Just by reading the test cases, people can easily grasp what we are trying to prove. If a long time later we come back and look at the tests, we still understand it clearly and easily.
Summary, this post demonstrates:
- Ability of Robot Framework to test Rest API
- Ability to read content from file
- Encode/decode JSON content
- Usage of Apiary as mock server
文章来源：http://nguyenthethang.com/2015/07/14/acceptance-test-robot-framework-test-returned-json-by-rest-api/
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