Forem: Pawan Garia

Secret Repo in GIT Hub

Pawan Garia — Wed, 22 Jul 2020 12:12:01 +0000

Found something very Interesting today about the GitHub.

In GitHub you can create a Repo with your username and this is the Repo content would be the homepage and You can write for example some details about yourself in the .md file and this would be highlighted on the Github home page.

Just Enter the name of your GitHub User.

Update and write something in your Readme.md file in the Repo and You have the new GitHub Landing page which shows this Read.md file content.

Try yourself and Enjoy :)

Browser Automation using Curl and ChromeDriver

Pawan Garia — Sat, 11 Jul 2020 22:39:54 +0000

Browser automation from command-line is possible after the release of HTTP servers like ChromeDriver, GeckoDriver which are implementing the W3C WebDriver standard and follow all the standards of a normal server-client architecture in HTTP.

In my other posts, I have described what is JSONWire Protocol and how it became a standard for the browser automation. I also described how we can perform browser automation using postman tool. Now in this article, I will show you how we can use simple curl HTTP commands to drive Chrome Browser.

Start ChromeDriver Server:

First, download the ChromeDriver and unzip the ChromeDriver to a particular directory. Now we need to first start the ChromeDriver Server like :

On Linux or Mac machines:

./chromedriver &

On Windows machine:

chromedriver.exe

After the successful start of the server you will see the following message on the terminal:

Starting ChromeDriver 2.33.506106 (8a06c39c4582fbfbab6966dbb1c38a9173bfb1a2) on port 9515
Only local connections are allowed.

Check Curl on your machine:

We will be using the Curl tool for the request and response, So the curl should be installed on your machine.
What is Curl
Curl is a command-line tool to transfer data. Curl support many of the data transfer protocols like DICT, FILE, FTP, FTPS, Gopher, HTTP, HTTPS, etc. Curl is a free and open-source project so there is no need for license or purchase. Anyone can install and start using curl. You can read more about Curl in the Following Git Book everything-curl. and Curl documentation page.

Curl can be downloaded from their website.. Windows Users can follow instructions from the following link

How to Check Curl on your machine

Open Command Line/Terminal on your machine and type following command:

$ curl -V

curl 7.43.0 (x86_64-apple-darwin15.0) libcurl/7.43.0 SecureTransport zlib/1.2.5
Protocols: dict file ftp ftps gopher http https imap imaps ldap ldaps pop3 pop3s rtsp smb smbs smtp smtps telnet tftp
Features: AsynchDNS IPv6 Largefile GSS-API Kerberos SPNEGO NTLM NTLM_WB SSL libz UnixSockets

This command will print the Curl version installed on your machine.

Now after running ChromeDriver and installing Curl successfully on our machine, we can start the steps for browser automation.

Step 1: Create a Session and Open Chrome Browser:

The first step is to create a session and you will see the browser is opened after this curl command.

curl  -d '{ "desiredCapabilities": { "caps": { "nativeEvents": false, "browserName": "chrome", "version": "", "platform": "ANY" } } }'  http://localhost:9515/session

{"sessionId":"27f4262ab044392b05138540055a8fd6","status":0}

Note down the SessionID from the response as we need the session Id for future requests

Step 2: Open Google.com URL:

Now after getting the session we will open the website url www.Google.com

curl -d '{"url":"https://www.google.com"}'http://localhost:9515/session/27f4262ab044392b05138540055a8fd6/url

{"sessionId":"27f4262ab044392b05138540055a8fd6","status":0,"value":null}

Step 3: Find the Search TextBox WebElement:

As we have opened the URL and now we need to find the Search text box WebElement.

curl -d '{"using":"name","value":"q"}' http://localhost:9515/session/27f4262ab044392b05138540055a8fd6/element

{"sessionId":"27f4262ab044392b05138540055a8fd6","status":0,"value":{"ELEMENT":"0.676163294199567-1"}}

Note down the ELEMENT Value from the response as this ElementID is representing the Element

Step 4: Enter Text in SearchBox WebElement:

Now we have the ElementID in which we want to send some text, So below Curl request will enter the text.

curl -d '{"value":["chrome"]}' http://localhost:9515/session/27f4262ab044392b05138540055a8fd6/element/0.676163294199567-1/value

{"sessionId":"27f4262ab044392b05138540055a8fd6","status":0,"value":null}

Step 4: Quit the Browser:

After Running the Steps We need to close the browser using the below curl command.

curl -X DELETE http://localhost:9515/session/27f4262ab044392b05138540055a8fd6

{"sessionId":"27f4262ab044392b05138540055a8fd6","status":0,"value":null}}

I have described and used very basic actions on the browser in this article but with the knowledge of WebDiver Json Wire Protocol, we can perform any action which can be done by Selenium WebDriver. Below is the small GIF for all the steps and action which we have discussed in this article.

Thanks for Reading!

Understanding the Architecture of Selenium WebDriver

Pawan Garia — Wed, 08 Jul 2020 10:23:29 +0000

Selenium WebDriver provides a programming interface for driving the browser for automation testing. You can find the introduction of WebDriver in my other article. This article is more about architecture and understanding how selenium WebDriver uses JSON Wire Protocol.

JSON Wire Protocol is an abstract specification of how automation behavior like clicking or typing or whatever you actually want to do with your automation script is mapped to selenium or appium or HTTP requests and response.

Why JSON Wire Protocol used in the first place?

To implement a client-server architecture that can give us the following benefits.

You write tests in any programming language.
You can perform or run test on cloud services like SauceLabs, BrowserStack or Selenium Grid setup.
You are not bound to run tests only on the local machine.
Different Drivers(FirefoxDriver, ChromeDriver) can be created for browsers and separate implementation by using the same standards.

So client-server implementation requires a standard set of the specification beforehand so that Server and Client should be in sync with each other in terms of what is coming and going on request and response. It's something like a language of communication with each other. So we need some common specifications to solve this kind of requirement and the solution is HTTP.

Why HTTP is the solution?

HTTP is a standard for the web and can be a good base for the specification. Every programming language has a good HTTP library that can be used for creating client and server for request and response calls.

How JSON Wire protocol works with HTTP?

HTTP request and response are generally made of verbs, route, body and response code which I am explaining here in details:

HTTP Verbs:

GET: Retrieve some information from server for example: getText, getTitle

POST: Make something happen for example: startSession, findElement, Click

DELETE: Delete some resource for example: deleteSession

HTTP Route:

There are many routes in JSON Wire Protocol used by WebDriver which you can check out here. Few examples:

GET   /status

POST  /session

GET   /Session

HTTP Response Code:

HTTP status codes are not specific enough for all the kind of things that might happen in Selenium WebDriver testing session. So for a specific case like NoSuchElement or Errors, we have a status code so that client can give particular and useful information back to the user. There are many response codes defined in WebDriver which you can find here in details but here are some examples:

0:   Success
7:   NoSuchElement
11:  ElementNotVisible
200: Everything OK
500: Something is wrong
404: Resource not there
501: Valid request but action not done by the server

HTTP Request and Response Body:

Everything is JSON in the request and response body. JSON is used for data transfer between client and server.

JSON Wire Protocol Request has route and body described in JSON like:

POST /session
{"desiredCapabilities" : {"browserName" : "chrome"}}

JSON Wire Protocol Response has status code and value in the body like a successful findElement request will give you the following response:

{"status" : 0, "value" : {"element" : "123422"}}

How Test work with HTTP and JSON Wire Protocol?

HTTP is a stateless protocol which means multiple requests are not associated with each other and server is not required to track the state of a particular client's previous request. Your test might be getting an Element in one request and clicking on the same Element in some another request, So Client and Server should share session, element, frame, etc. with each other in subsequent requests.
So the server assigns a unique ID to these Items like session and Element and then shares them with Client. The client can decide in the request like what needs to be done on the particular ID like click on an element.

Client makes a findElement call to the server and gets the response:

  Request:  POST  /session/::sessionId/element
  Response: {“status”:0, “value”:{“element":”elementID”}}

Now the client knows the elementID from the previous request's response and sends a click request with elementID.

   Request:  POST  /session/::sessionId/element/::elementID/click
   Response: {“status” : 0}

What WebDriver is doing in JSON Wire protocol?

Selenium WebDriver is a client which is giving an interface to write tests in programming languages like Java or Python or many other languages in the market. The server doesn't care or know about what language you are using for writing your tests because it only cares about the correct protocol which is JSON Wire protocol. So you can also make your own Selenium Webdriver in your choice of programming language. :)

Thanks for reading!