Weekend Reads - API Testing (Web Service Testing, Inspect Http request, Rest API Testing) - Free tools

Very good presentation on compiled list of free tools for API Testing. More Details - Free API debugging and testing tools you should know about

Tools List from the presentation and SO reads

• Rest-assured - Java DSL for easy testing of REST services
• Retrofit - A type-safe REST client for Android and Java
• RequestBin - Inspect HTTP Requests
• Hurl.it — Make HTTP Requests
• ngrok captures all traffic - Raw request/response bytes
• mitmproxy: a man-in-the-middle proxy - Intercept, modify, replay and save HTTP/S traffic
• Postman is a powerful HTTP client to help test web services easily and efficiently
• Mock your HTTP responses to test your REST API
• Chrome Rest Console - REST Console is an HTTP Request Visualizer 
• SO - Online testing a REST service
• Simple REST and HTTP API Client for .NET

While reading through the list again went back to check on SOAP, Rest Basics. API testing / Web Service testing we will be looking into only aspects Rest, SOAP based web services. Summary based on StackOverflow readings, posts. References - StackOverflow reference answers link. More details Pls check reference link. (Consolidated Answer and Detailed short summary listed below)

Rest	SOAP
REST is over HTTP. REST has no WSDL interface definition	SOAP can be over any transportprotocols such HTTP, FTP, STMP, JMS etc.
REST stands for Representational State Transfer. REST approach uses the standard GET, PUT, POST, and DELETE verbs	Simple Object Access Protocol (SOAP)  SOAP builds an XML protocol on top of HTTP  / TCP/IP.
REST is good for getting a blob of data that you don't have to work with	SOAP describes functions, and types of data. If you want to get an object, SOAP is way quicker and easier to implement
Typically uses normal HTTP methods instead of a big XML format describing everything	Has several protocols and technologies relating to it: WSDL, XSDs, SOAP, WS-Addressing
REST plays well with AJAX'y web pages. If you keep your requests simple, you can make service calls directly from your JavaScript, and that comes in very handy.	SOAP is useful from a tooling perspective because the WSDL is so easily consumed by tools. So, you can get Web Service clients generated for you in your favourite language.

More Reads

HTTP vs REST vs SOAP

REST and SOAP: When Should I Use Each (or Both)?

From AWS Blog - 80% REST / 20% SOAP usage pattern

Example - Learn REST: A Tutorial
Restful Load Testing

Happy Learning!!!

.NET 2.0 Web Services Functional Test Automation

I'm reading book .Net Test automation recipies. If I had got this book 3 years back this could have helped me alot in automation. Never too late. I love this book. Thanks to the author for his great work. I used to use tool WebServiceStudio for Web Services Testing since 2006 (Long time back :))

• I have attempted creating a simple asp.net webservice
• Testing the same using Httpwebrequest POST

This is a skeleton only, The next post I'm planning to cover

• Trying same example for WCF Service
• Implement Data Driven Testing for this example using Nunit
• Logging and Reporting

 Step 1 - Create a simple web service

Step 2 - Below sample project would be created, Modify the code for addition of two numbers

[WebMethod]

public int AddNumbers(int a, int b)

{

    return a+b;

}

Step 3 - View in Browser, You will see the SOAP Request

Step 4 - Created a Console Application

Copy - Paste below code in the Console App. Provide the correct modified URL for the webapp.

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Net;

using System.Data;

using System.IO;

namespace WebServiceAutomation

{

    class Program

    {

        static void Main(string[] args)

        {

            Console.WriteLine("Calling AddSum webmethod");

            int input1 = 10;

            int input2 = 20;

            int expectedresult = 30;

            int actualresult;

            string postData = @"<?xml version=""1.0"" encoding=""utf-8""?>

                <soap:Envelope xmlns:xsi=""http://www.w3.org/2001/XMLSchema-instance"" xmlns:xsd=""http://www.w3.org/2001/XMLSchema"" xmlns:soap=""http://schemas.xmlsoap.org/soap/envelope/"">

                <soap:Body>

                <AddNumbers xmlns=""http://tempuri.org/"">

                <a>input1</a>

                <b>input2</b>

                </AddNumbers>

            </soap:Body>

            </soap:Envelope>";

            postData = postData.Replace("input1",input1.ToString());

            postData = postData.Replace("input2",input2.ToString());

            byte[] buffer = Encoding.ASCII.GetBytes(postData);

            string url = "http://localhost:1033/Service1.asmx?op=AddNumbers";

            HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url);

            req.Method = "POST";

            req.ContentType =  "text/xml";

            req.ContentLength = buffer.Length;

            req.Timeout = 5000;

            Stream request = req.GetRequestStream();

            request.Write(buffer, 0, buffer.Length);

            request.Flush();

            request.Close();

            HttpWebResponse res = (HttpWebResponse)req.GetResponse();

            Stream resst = res.GetResponseStream();

            StreamReader sr = new StreamReader(resst);

            string response = sr.ReadToEnd();

            Console.WriteLine("HTTP Response is " + response);

            Console.ReadKey();

            int start = response.IndexOf("<AddNumbersResult>");

            int end = response.IndexOf("</AddNumbersResult>");

            string Actualresult = response.Substring(start+18, end - start-18);

            Console.WriteLine("Expectd Result is " + expectedresult +"\n");

            Console.WriteLine("Actual Result is " + Actualresult + "\n");

            Console.ReadKey();

        }

    }

}

Step 5 - Output Window After executing the Console App

Explanation for the code

• If you want to interact more directly with a Web server, the HttpWebRequest and HttpWebResponse add additional methods that make this easier
• HttpWebRequest and HttpWebResponse class is inside the System.NET namespace, and this two classes is designed to communicate by using the Http Protocol
• HttpWebRequest can be used to send HTTP request to the server
• Stream Class – msdn link  
• The Stream class is abstract
  Means that same code can be used to read from or write to any kind of secondary storage (aka the backing store)
• The StreamWriter class is derived from an abstract class called TextWriter, which writes characters to a stream or file
  The StreamReader class is derived from an abstract class called TextReader, which reads characters from a stream or file
• StreamWriter is quite a bit different than StreamReader
• StreamReader converts text to string or char[ ]
• It does not do "text to numeric/object" conversions
• You have to manually parse and convert the input
• StreamWriter automatically converts all types of binary data to human-readable text for display
• Stream Reader
• Read a line from the file using the ReadLine() method
• Returns a string if OK, null on end-of-file
• Stops reading when newline or "\r\n" encountered
• End-of-line is discarded
• Read entire file into a single string using ReadToEnd()

More Reads

• Learn Basics of how web services work - Anatomy of an XML Web Service Lifetime
• How To: Create a “Hello World” WCF Service Using Visual Studio
• Call WCF Webservice from Windows Application using HTTPWebRequest
• A Cleaner - Soap based Web Service & WCF Test Tool
• WCF Load Test Version 3.0 (Beta) for Visual Studio 2010
• How to Create a WCF Client for ASMX Web Service Without Using Web Proxy
• Automate Your ASP.NET Web Services Testing
• wizdl - Web Service GUI Test Tool
• Creating a Data-Driven Web Test against a Web Service
• Generate thousand of request using httpwebrequest
• Call XML webservice through c#.net

SOAP Vs REST (Representative State Transfer (REST))

1. REST stands for Representational State Transfer, this basically means that each unique URL is a representation of some object
2. It embraces a stateless client-server architecture in which the web services are viewed as resources and can be identified by their URLs. Source - Link
3. REST has no WSDL interface definition
4. REST is over HTTP, but SOAP can be over any transport protocols such HTTP, FTP, STMP, JMS etc.
5. SOAP is using soap envelope, but REST is just XML
6. SOAP RPC: Verb based. GetUser(string userId), AddUser(User u)
7. REST: Noun based. Ex- http://mysite/users/dseven, http://mysite/users/newUserForm
8. REST does NOT require a separate page for each data item, just a separate address.

Good Read - REST vs. SOAP – The Right WebService
Soap Headers Authentication in Web Services
CodeSnip: Handling SOAP Exceptions in Web Services
Interview Question: Compare two web services type SOAP and RESTful (SOAP Vs RESTful)
XML comparison tutorial using XMLUnit
Consuming Twitter APIs

Hope it Helps.

Happy Reading!!