Category Archives: Coding Stuff

C# Advent Calendar – Combining Integration and UI Automation in C#

I signed up for the C# Advent Calendar with this post – be sure to check out the rest of the blog posts in the calendar! This post assumes you’ve got some experience with C# and Visual Studio, so I won’t be over-explaining some things. Comment if you get stuck or have questions!

If you’re here for the first time, welcome! I’m a “career QA”, been in the QA/testing field for just over 10 years now. I’ve been doing test automation with C# for several years, including CodedUI, Selenium, and integration tests (using NUnit or MSTest) for REST services, as well as unit testing. So I’m kicking off the C# Advent Calendar with a testing topic. Hope you enjoy!


My talk on Testing RESTful Web Services is all about evangelizing integration testing. Integration tests are sometimes missed between unit tests and GUI tests – developers may think it’s the QA’s job, and QA may think it’s the developer’s job, so they can fall through the cracks.

no_integration_test.gif

So why combine integration and UI tests? These are useful to see if the API and the UI are speaking the same language. They are often developed at the same time by different people, so it’s nice to have a safety net of tests that can be run whenever to verify things are still working properly.

I wrote a very simple web API for funsies (using this tutorial) and because it has an API and a web UI, it seemed like a great subject for this mixed tests treatment! My code can be found at my github, here: https://github.com/g33klady/MontyPythonApi.

Our test will:

  • do a GET via the API for an item
  • launch the UI and search for the same item
  • compare the responses

Creating The Class Library For The Tests

Because this is pretty small, I’m just going to use a single project for my tests. In a larger application I might split them out. I’ll create a Class Library for all of my testing stuff. The first thing I do in general is add all of the NuGet Packages I need.

NuGetPackages

I then set up my structure.

For the UI tests, I know I’ll be using the Page Object Model so I create a folder for those, and add my HomePage class. I also know I’ll need some utility methods, so I add a Utilities class. I’ll wait to add the test classes until I’m ready for them.

ProjectStructure1

Setting Up The Page Objects

In essence the Page Object Model is decoupling the definitions of the elements on a page from the tests that use/manipulate them. This keeps the tests maintainable and not as brittle.

Our page is pretty simple. I’ve pointed out the elements we’ll want to put into the class. We’ll just be typing a number into the text field, clicking Search, and reading the response in the div below that.

webpage_objectsIndicated

Each of my elements has an ID – easily identifiable elements helps us QA folks use the elements in automation. If I have to use Xpath, for example, the tests can be more brittle than if I tell the automation “find this thing with this unique identifier”.

This is what my class looks like with the text field identified:

using OpenQA.Selenium;
using OpenQA.Selenium.Support.PageObjects;
 
namespace MontyPythonApi.Tests.PageObjects
{
	public class HomePage
	{
		[FindsBy(How = How.Id, Using = "prodId")]
		public IWebElement ProductIdInput { get; private set; }
	}
}

The FindsBy is how Selenium will be finding the element, and then the property is of type IWebElement (so Selenium can find it) and I can call it whatever I want. I like to use the type of element it is in the name to make it more clear, especially when there’s tons of elements in there.

I’ll add the rest of the page elements, and then initializing the elements via the PageFactory (part of Selenium.Support.PageObjects):

using OpenQA.Selenium;
using OpenQA.Selenium.Support.PageObjects;
 
namespace MontyPythonApi.Tests.PageObjects
{
	public class HomePage
	{
		[FindsBy(How = How.Id, Using = "prodId")]
		public IWebElement ProductIdInput { get; private set; }
 
		[FindsBy(How = How.Id, Using = "searchButton")]
		public IWebElement SearchButton { get; private set; }
 
		[FindsBy(How = How.Id, Using = "product")]
		public IWebElement ProductDisplayOutput { get; private set; }
 
		public HomePage(IWebDriver browser)
		{
			PageFactory.InitElements(browser, this);
		}
	}
}

Any methods specific to this page will also go here. We can add them as we need them.

Setting Up The Utility Methods

For our integration tests, we’ll need to make HTTP Web Requests, and then get the response back and deserialize it. I prefer to deserialize it in the test itself, but if you want to do it in the utilities be my guest 😀

Our utility class looks like this (the formatting sucks – check out the code instead here):

using System;
using System.Net.Http;
using System.Text;
 
namespace MontyPythonApi.Tests
{
	public class Utilities
	{
		public static HttpResponseMessage SendHttpWebRequest(string url, string method, string content = null)
		{
			using (var httpClient = new HttpClient())
			{
				var httpMethod = new HttpMethod(method);
 
				using (var httpRequestMessage = new HttpRequestMessage { RequestUri = new Uri(url), Method = httpMethod })
				{
					if (httpMethod != HttpMethod.Get && content != null)
					{
						httpRequestMessage.Content = new StringContent(content, Encoding.UTF8, "application/json");
					}
					return httpClient.SendAsync(httpRequestMessage).Result;
				}
			}
		}
 
		public static string ReadWebResponse(HttpResponseMessage httpResponseMessage)
		{
			using (httpResponseMessage)
			{
				return httpResponseMessage.Content.ReadAsStringAsync().Result;
			}
		}
	}
}

Now We Can Write Our Test!

Now to the good stuff.

I start with the SetUp method, which runs prior to every test. This is where I set the browser driver up – what Selenium uses to make the browser bend to its will.

using NUnit.Framework;
using OpenQA.Selenium;
using OpenQA.Selenium.Chrome;
 
namespace MontyPythonApi.Tests
{
	[TestFixture]
	public class IntegrationAndUiTests
	{
                private IWebDriver browser;
		private static string webUrl;
		private static string apiUrl;
		private static string baseUrl;
 
		[SetUp]
		public void Setup()
		{
			browser = new ChromeDriver();
			baseUrl = "http://localhost:20461";
			webUrl = baseUrl + "/index.html";
			apiUrl = baseUrl + "/api/products";
		}
        } 
}

I instantiate the browser driver (using IWebDriver from Selenium) in the SetUp method because each test will need a new instance of it. Like all good tests, these need to be atomic.

We need a TearDown method as well, to clean up after ourselves.

[TearDown]
public void TearDown()
{		
	browser.Quit();
}

I’m going to set up my test to first make the call to the API, then use an Assert to verify that I got a 200 OK response back. This isn’t necessary but I find it useful – my tests fail here rather then trying to deserialize later on, so I know where things went wrong more quickly.

So we know our test is going to make a call to the API about a product, then verify the data in the web UI. We have a requirement that if a product has a discount price, it’s the only price that will display in the web UI. We set up our test data so that the product with ID = 1 has a discount price, so that will be the subject of our test.

[Test]
public void ProductsDiscountPriceDisplaysOnWebPage()
{
	//API call
	var uri = apiUrl + "/1"; //get the product with ID = 1
	var apiResponse = Utilities.SendHttpWebRequest(uri, "GET");
	Assert.That(apiResponse.IsSuccessStatusCode, 
		"Did not get success status code; got " + 
                apiResponse.StatusCode.ToString());
}

Our test has started to take shape. We are making our call, and getting the response back. We’re verifying  it got a 200 OK back but nothing else with it yet.

Let’s deserialize the response, so we can get the discount price value. To do that, I need to add the reference to the API project first, so I can use the model.

Here’s my code now, after having deserialized the response, using the utility method to read the response content into a string:

[Test]
public void ProductsDiscountPriceDisplaysOnWebPage()
{
        //API call
	var uri = apiUrl + "/1"; //get the product with ID = 1
	var apiResponse = Utilities.SendHttpWebRequest(uri, "GET");
	Assert.That(apiResponse.IsSuccessStatusCode, 
		"Did not get success status code; got " + 
		apiResponse.StatusCode.ToString());
	Models.Product product = JsonConvert.DeserializeObject(Utilities.ReadWebResponse(apiResponse));
}

Now we have the data that is returned for the product. We can now launch the web browser with Selenium and get the data returned in the web UI.

I need to have the browser go to the url, and then instantiate my page object:

//WebUI
browser.Navigate().GoToUrl(webUrl);
PageObjects.HomePage page = new PageObjects.HomePage(browser);

Now I can use the properties of page to interact with the elements on the page.

//WebUI
browser.Navigate().GoToUrl(webUrl);
PageObjects.HomePage page = new PageObjects.HomePage(browser);
page.ProductIdInput.SendKeys("1");
page.SearchButton.Click();

I’m essentially typing 1 into the search field, and clicking the search button.

Next I need to read the display of the data as it came back for that product. It comes back in a string with the format <Name> : $<Price> so I’ll need to parse it. Because this is something I’ll be doing on this page for more tests, I’ll add this utility method to the HomePage class.

public string GetPriceFromDisplayText(string displayText)
{
        decimal result;
	Regex r = new Regex("\\$(.*)");
	Match m = r.Match(displayText);
        decimal.TryParse(m.Groups[1].Value, out result);
	return result;
}

Definitely could hit some exceptions along the way, but for now we’ll leave it as-is.

Now our Web call looks like this:

//WebUI
browser.Navigate().GoToUrl(webUrl);
PageObjects.HomePage page = new PageObjects.HomePage(browser);
page.ProductIdInput.SendKeys("1");
page.SearchButton.Click();
var displayedPrice = page.GetPriceFromDisplayText(page.ProductDisplayOutput.Text);

And we can finally add that assert statement to check our values! Here’s our full test:

[Test]
public void ProductsDiscountPriceDisplaysOnWebPage()
{
	//API call
	var uri = apiUrl + "/1"; //get the product with ID = 1
	var apiResponse = Utilities.SendHttpWebRequest(uri, "GET");
	Assert.That(apiResponse.IsSuccessStatusCode, 
		"Did not get success status code; got " + 
		apiResponse.StatusCode.ToString());
	Models.Product product = JsonConvert.DeserializeObject(Utilities.ReadWebResponse(apiResponse));
 
	//WebUI
	browser.Navigate().GoToUrl(webUrl);
	PageObjects.HomePage page = new PageObjects.HomePage(browser);
	page.ProductIdInput.SendKeys("1");
	page.SearchButton.Click();
	var displayedPrice = page.GetPriceFromDisplayText(page.ProductDisplayOutput.Text);
 
	Assert.AreEqual(product.DiscountPrice, displayedPrice, "The prices don't match!");
			
}

Let’s run it and see what we get! Because the API and the tests live in the same solution, we’ll need to open a new instance of Visual Studio to run the tests locally.

Time For Some Results

And… our test fails!

TestResult

There’s a bug in the UI code that should display the discount code. Would we have found this otherwise? Probably with a good unit test, but this is a nice way to combine our tests and see how the application really behaves.

I’m leaving the bug there in the repo, so you can follow along. All of the code demonstrated above is there.

Let me know what you think – is this something you could use? Is this too much overhead for your project? Is this useful?

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Using SQL Databases and REST together in Integration Automation with C# and NUnit

EDIT: One mindful reader noted that I should be using good practices to protect my code from SQL Injection. So there are some updates below, and the code is also updated! I used this as my guide: https://msdn.microsoft.com/en-us/library/system.data.sqlclient.sqlcommand.parameters.aspx


One part of my talk and resources on Testing RESTful Web Services that I hinted at but didn’t quite get to was using SQL databases. A lot of us will be testing a REST service along with it’s backing SQL database, so it’s useful to know how to link them together in our C# automation!

I’ve added to my repository to include some checks against the AdventureWorks2012 SQL database, continuing to use C# and NUnit. Gitter’s database isn’t publicly available (nor should it be!) and I can’t find an AdventureWorks API that I could use for my checks – maybe that will be a later, more complete example. But for now, we’re doing some pretending!

If you’d like to follow along, grab the AdventureWorks2012 database backup from Microsoft by grabbing this zip AdventureWorks2012-Full Database Backup.zip. Unzip and restore the database (google it if you need help :D).

Look through the tables, run some queries, and see what we’re working with. For the coding examples in the repo, I’m mainly looking at the Production.ProductInventory table, which depends on the Production.Product table for ProductIds. From the Product table, I’m going to pick a product to work with – I like #875: Racing Socks, L. Querying the ProductInventory table, I see there’s 288 (presumably pairs) of Large Racing Socks.

Let’s pretend that we have an inventory system that uses a REST service, which in turn grabs data from and updates our database. If we pull something off the shelf to send to a customer, we scan it into the system. The system identifies it, and sends a call like:

PUT http://ourwarehouse/api/products/875/inventory/-1

then the API goes into the database and essentially does:

UPDATE Production.ProductInventory 
SET Quantity = quantity - 1 where ProductID = 875

So with our checks, we would:

  1. Do a SELECT query on the database for the product and see what the quantity is
  2. Perform the PUT operation with the REST service
  3. Do the SELECT query again to see what the quantity is now
  4. Verify the new quantity is what we’re expecting

Utility Methods

First we can write some utility methods to execute our queries against the database. We start with a Utility class and add references to System.Data and System.Data.SqlClient.

Our first utility method is to execute a SQL query to get the quantity of a product. We’ll pass the product ID and connection string, and it will return a DataTable for us.

public static DataTable GetQuantityOfProduct(string productId, 
  string connectionString)
{
	string commandText = "SELECT Quantity FROM " +
                 "AdventureWorks2012.Production.ProductInventory WHERE " +
                 "ProductID = @ID;";
	using (SqlConnection connection = new SqlConnection(connectionString))
	{
		SqlCommand command = new SqlCommand(commandText, connection);
		command.Parameters.Add("@ID", SqlDbType.NVarChar);
		command.Parameters["@ID"].Value = productId;
		using (var da = new SqlDataAdapter(command))
		{
			var dt = new DataTable();
			da.Fill(dt);
			return dt;
		}
	}
}

Another utility method we’ll want is to execute an Update SQL command, to update the quantity (since we don’t have an API).

Again this method takes in the product ID, as well as quantity and connection string, but this method returns a code, not a DataTable. If our command is successful, we’re expecting the return code to be the number of rows affected. If it’s -1, then something went wrong.

public static int UpdateQuantityOfProduct(string productId, int quantity,
 string connectionString)
{
	int code = 0;
	string commandText = 
            "UPDATE AdventureWorks2012.Production.ProductInventory " +
            "SET Quantity = @Quantity WHERE ProductID = @ID;";
	using (SqlConnection connection = new SqlConnection(connectionString))
	{
	   using (SqlCommand command = new SqlCommand(commandText, connection))
	   {
		command.Parameters.Add("@Quantity", SqlDbType.Int);
		command.Parameters["@Quantity"].Value = quantity;
		command.Parameters.Add("@ID", SqlDbType.NVarChar);
		command.Parameters["@ID"].Value = productId;
		connection.Open();
		code = command.ExecuteNonQuery();
		command.Dispose();
	   }
	}
	return code;
}

 

Connection Strings

We’ll put our connection string for the database in our App.config file. We need to specify the server, which database, and the security we’re using. Mine is set up locally, with Integrated Security (Windows Authentication).

<appSettings>
    <add key="dbConnectionString" value="Data Source=MSSQLSERVER12;
            Initial Catalog=AdventureWorks2012;Integrated Security=True"/> 
</appSettings>

We’ll grab the connection string in the SetUp method in our test class:

private static string _connectionString;
[OneTimeSetUp]
public void SetUp()
{
     _connectionString = ConfigurationManager.AppSettings["dbConnectionString"];
}

The First Check

Let’s get started with our first check! Remember we’re going to:

  1. Do a SELECT query on the database for the product and see what the quantity is
  2. Perform the PUT operation with the REST service
  3. Do the SELECT query again to see what the quantity is now
  4. Verify the new quantity is what we’re expecting

0. Setup

First we need to specify a few things, including which product we’re going to use, how we’re going to modify the quantity, and create our query string.

int quantityModifier = -1;
string productId = "875";

So we’re going to take 1 away from our inventory, of product 875 or the amazing racing socks in large.

 

1. Do a SELECT query on the database to get initial quantity

First we execute the query, and get a DataTable in return. We could return just that individual field, but then our utility method wouldn’t be as useful or we’d have too many doing the same thing -sometimes we’ll want an entire row, sometimes we’ll want many rows. You can do it either way. Here, we’ll do the work in our test to get the field we want, which is the first row and first column.

DataTable initialInventoryDt = 
    Utilities.GetQuantityOfProduct(productId, _connectionString);
int initialQuantity = Int32.Parse(initialInventoryDt.Rows[0][0].ToString());

Now we can figure out what the expected quantity will be when we’re done with our check.

int expectedQuantity = initialQuantity + quantityModifier;

2. Peform PUT operation with the REST service

If we had this pretend REST service set up, our code now would look something like this:

string url = String.Format("http://ourwarehouse/api/products/{0}/inventory/{1}, 
    productId, quantityModifier");
HttpResponseMessage response = Utilities.SendHttpWebRequest(url, "PUT");
Assert.IsTrue(response.IsSuccessStatusCode, 
    "Response code to PUT was not successful");

However, we don’t. So we have to fake it by doing an UPDATE command to the database directly.

 

And we add this code:

int code = UpdateQuantityOfProduct(productId,expectedQuantity,_connectionString);
Assert.IsTrue(code == 1, "more than 1 row was affected, something went wrong");

REMEMBER this is ONLY because we don’t have that REST service and we’re faking what the service would do!

3. Do the SELECT query again to get the new quantity

Again we perform our select query, and grab the returned value

DataTable updatedInventoryDt = 
    Utilities.GetQuantityOfProduct(productId, _connectionString);
int updatedQuantity = Int32.Parse(updatedInventoryDt.Rows[0][0].ToString());

4. Verify the new quantity that we’re expecting

Now we just do our Assert!

Assert.AreEqual(expectedQuantity, updatedQuantity, 
    "Updated Quantity is not as expected; it is " + updatedQuantity + 
    " but should be " + expectedQuantity);

Other Checks

We could also do a check of the GET method, to make sure our service is pulling information from the right table. Our steps would be:

  1. Do a SELECT query on the database for the product to get the quantity
  2. Perform the GET operation with the REST service to get the quantity
  3. Verify the quantities returned from both match

This example is in the repo, so you can check it out there!

There are many other variations that we could perform, as well, but these are some basic building blocks.

Wrap Up

I hope that this walkthrough and the code help you to be able to automate checks against SQL databases as well as REST services! Let me know if you think something is missing, or if you need some clarity, or if you find a bug in my code!

Also apologies about the formatting here – I need to find a good code snippet plugin to use in WordPress! Let me know if you have any suggestions!

She used this one neat trick to model JSON as classes in C#, and her audience was stunned!

I recently presented my talk Testing RESTful Web Services for the first time at the QL Technology Conference in Detroit. In this talk, I cover why we should test web services, and how to test RESTful web services both with tools like Postman, and C# and NUnit.

I was not prepared for, mid-demo, resounding applause from the audience. I was demoing a cool trick I learned from a teammate, and apparently it was new magic to the audience. Awesome! So I decided to blog about it, to spread the word of this fancy magic and help everyone save time when testing RESTful web services within Visual Studio.

What was that magic? It’s the ability to take a JSON response and quickly turn it into a class – a super fast way to model JSON responses!

applause

Huzzah!

If you already know how to do it, awesome! Spread the word!

What you need:

  • a JSON response to copy/paste
  • Visual Studio, with a solution loaded (we’ll use C#, not sure how it works with other languages)

I’ll use the same examples from my talk – it uses the gitter API (http://gitter.im).

First, create a new class file in your project:

  • Right-click in Solution Explorer where you want the file to go
  • Select Add -> Class
  • Type a name and click Add

Then, paste the JSON as classes!

  • Copy the JSON you want to model as a class
  • Inside the class file in Visual Studio, put your cursor inside the namespace
  • Choose Edit -> Paste Special -> Paste JSON As Classes
  • Much rejoicing!

You’ll need to clean up the class a bit, but it will definitely save you time!ClassesAndJson.png

I hope you’re able to use this neat trick to help you in your testing of web services!

You will want to choose your JSON responses for modeling carefully – make sure it has all of the potential properties! Otherwise, down the road when you’re deserializing, you’ll hit a failure because the JSON will have an extra property that your class is missing.

Any other neat tricks you can share?