Writing unit
tests for Happy, Sad and bad path.
In this article i will explain writing unit test cases that cover negative and positive scenarios to test data.
Unit test case that covers either happy path or sad path , what is this new term bad path ; check last example
you will get better idea.
Happy path test Method:
A test case
which results you in a positive result is a happy path.
Entering
proper email address, username is valid data.
Example:
C#
validation Code:
public bool ValidateProductame(Product Product)
{
if (string.IsNullOrEmpty(Product.ProductName))
return false;
return true;
}
Test Method:
/// <summary>
/// validates Product
name.
/// Result is valid
Product Name.
/// </summary>
[TestMethod]
public
void
ChaekValidProductName()
{
var target =
_ProductValidation;
var product = new Product()
{
ProductName = "CodeChef4u SQL rcipies",
Price = 500,
Category = new ProductCategory()
{
CategoryName =
"Book"
},
ImageUrl = @"C:/data"
};
Assert.IsTrue(target.ValidateProductame(product));
}
Sad path unit test Method:
A test case
which gives expected results for invalid data is sad path test method.
For example entering empty or null username.
C#
validation Code:
public bool ValidateProductame(Product Product)
{
if (string.IsNullOrEmpty(Product.ProductName))
return false;
return true;
}
Test method:
/// <summary>
/// validates Product
name.
/// Result is invalid
Product Name.
/// </summary>
[TestMethod]
public
void
ChaekEmptyProductName()
{
var target =
_ProductValidation;
var product = new Product()
{
ProductName = "",
Price = 115,
Category = new ProductCategory()
{
CategoryName = "Book"
},
ImageUrl = @"C:/data"
};
Assert.IsFalse(target.ValidateProductame(product));
}
Bad path unit test Method:
With this
you can test entering some invalid data A test case which results you some
Valid message
you are expecting.
C# validation code:
public bool
ValidatePrductNameWithSpecialChar(Product Product,out string
ErrorMessage)
{
var regexItem = new Regex("^[a-zA-Z0-9 ]*$");
if
(regexItem.IsMatch(Product.ProductName))
{
ErrorMessage = "Special characters not allowed";
return
false;
}
ErrorMessage = "";
return
true;
}
Test method:
/// <summary>
/// Validates Product
name.
/// Result is valid
Product Name.
/// </summary>
[TestMethod]
public
void
ChaekBadProductNameForSpecialChar()
{
string
ExpectedErroMessage = "Special
characters not allowed";
string
TargetMessage;
var target =
_ProductValidation;
var product = new Product()
{
ProductName = "CodeChef4u ) SQL rcipies",
Price = 500,
Category = new ProductCategory()
{
CategoryName =
"Book"
},
ImageUrl = @"C:/data"
};
var
isFailed=target.ValidatePrductNameWithSpecialChar(product,out TargetMessage);
Assert.AreEqual(ExpectedErroMessage,
TargetMessage);
}
Writing Unit testing in C# with moq
What is Unit testing?
Wikipedia definition
Unit testing
is a software testing method by which individual units of source code, sets of one
or more computer program modules together with associated control data, usage
procedures, and operating procedures, are tested to determine whether they are
fit for use.
Reference: https://en.wikipedia.org/wiki/Unit_testing
What is Moq?
Moq is the mocking
library for .NET developed that take full advantage of .NET 3.5 (i.e. Linq
expression trees) and C# 3.0 features (i.e. lambda expressions) that make it
the most productive, type-safe and refactoring-friendly mocking library
available. And it supports mocking interfaces as well as classes.
Installing Moq:
You can download
Moq from GitHub and add the appropriate references to your project, or you can
install it using nugget package manager.
Unit testing in VS 2013 with Moq:
I want to
test validation business logic for my finance web application following business
entities I am using for product data.
public class
Product
{
public
int
ProductId { get; set; }
public
string
ProductName { get; set; }
public
decimal Price { get; set; }
public
ProductCategory Category { get; set; }
public
string
ImageUrl { get; set; }
}
Product data validation logic and used
interfaces for notication:
namespace C4RandDWebApp
{
public class
ProductDataValidation
{
private readonly ILogger _logger;
private
readonly IEmailer _emailer;
public
ProductDataValidation(ILogger Logger, IEmailer Emailer)
{
_logger = Logger;
_emailer = Emailer;
}
public
bool
ValidateProductame(Product Product)
{
if (string.IsNullOrEmpty(Product.ProductName))
return
false;
{
_logger.LogWarning("Invalid username" + Product.ProductName);
// Email internet dev
_emailer.SendWarningEmail(Product.ProductName,
"Invalid username");
}
return
true;
}
public
bool
ValidateProductPrice(Product Product)
{
if (Product.Price == null || Product.Price ==
0M)
return
false;
return
true;
}
public
bool
ValidateProductCategory(Product Product)
{
if (string.IsNullOrEmpty(Product.Category.CategoryName))
return
false;
return
true;
}
}
}
Created unit testing project named C4Testing and added all required dll reference to project.
Created following test class inside project that unit tests all scenarios for my application product data validation.
Unit testing Class with Moq:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Moq;
using
Microsoft.VisualStudio.TestTools.UnitTesting;
using C4RandDWebApp;
namespace C4Testing
{
/// <summary>
///This is a test class for
Product validation and is intended
///to contain all Product validation Unit Tests
///</summary>
[TestClass]
class ProductDataValidationTests
{
// Mocks
private
Mock<ILogger>
_mockLogger;
private
Mock<IEmailer>
_mockEmailer;
//Declaration
private
IProductDataValidation _ProductValidation;
//initalize
[TestInitialize]
public
void ProductValiatotInitialise()
{
_mockLogger = new Mock<ILogger>();
_mockEmailer = new Mock<IEmailer>();
_ProductValidation = new C4RandDWebApp.ProductDataValidation(_mockLogger.Object, _mockEmailer.Object);
}
#region Sad Path
/// <summary>
/// Validates Product
name.
/// Result is invalid
Product Name.
/// </summary>
[TestMethod]
public
void
ChaekEmptyProductName()
{
var target =
_ProductValidation;
var product = new Product()
{
ProductName = "",
Price = 115,
Category = new ProductCategory()
{
CategoryName = "Book"
},
ImageUrl = @"C:/data"
};
Assert.IsFalse(target.ValidateProductame(product));
}
#endregion
#region Happy Path
/// <summary>
/// validates Product
name.
/// Result is valid
Product Name.
/// </summary>
[TestMethod]
public
void
ChaekValidProductName()
{
var target =
_ProductValidation;
var product = new Product()
{
ProductName = "CodeChef4u SQL rcipies",
Price = 500,
Category = new ProductCategory()
{
CategoryName =
"Book"
},
ImageUrl = @"C:/data"
};
Assert.IsTrue(target.ValidateProductame(product));
}
#endregion
}
Creating Unit Tests using C# and Visual Studio
Creating C4ShopDataValidation
Library project for product data validation
Steps:
1. Open
Visual Studio.
2. On the
File menu=> New=>click Project.
3. New
Project dialog box appears.
4. Installed
Templates=> click Visual C#.
5. In the list
of application types, click Class Library.
6. In Name
box, type “C4ShopDataValidation” and
then click OK.
Example:
Sample methods
under test
public bool ValidateProductame(ProductProduct)
{
if (string.IsNullOrEmpty(Product.ProductName))
returnfalse;
returntrue;
}
public bool
ValidatePrductNameWithSpecialChar(Product Product,out string
ErrorMessage)
{
var regexItem = new Regex("^[a-zA-Z0-9 ]*$");
if (regexItem.IsMatch(Product.ProductName))
{
ErrorMessage = "Special characters not allowed";
return
false;
}
ErrorMessage = "";
return
true;
}
Create C4Test Project for unit
testing:
Steps:
1. File menu=>Add=> New Project .
2. New Project dialog box=> expand
Installed=>expand Visual C#=>Test.
3. Appears list of templates=>select Unit Test
Project.
4. In the Name box, enter BankTest, and then
choose OK.
5. Provide nem “C4Test” now project is added to
the the C4Shop solution.
6. In the C4Test project, add required references
i.e C4ShopDataValidation,BusnessEntities.
7. Rename existing Class Class.1 or Add new if
you want
8. Start writing test cases.
Example:
Unit test methods for product name validation
[TestClass]
public class
ProductDataValidationTests
{
//Declaration
private
IProductDataValidation _ProductValidation;
//initalize
[TestInitialize]
public
void
ProductDataValidationInitialise()
{
_ProductValidation = new ProductDataValidation();
}
#region Sad Path
[TestMethod]
public
void
ChaekEmptyProductName()
{
var target =
_ProductValidation;
var product = new Product()
{
ProductName = "",
Price = 115,
Category = new ProductCategory()
{
CategoryName = "Book"
},
ImageUrl = @"C:/data"
};
Assert.IsFalse(target.ValidateProductame(product));
}
[TestMethod]
public
void
ChaekBadProductNameForSpecialChar()
{
string
ExpectedErroMessage = "Special
characters not allowed";
string
TargetMessage;
var target =
_ProductValidation;
var product = new Product()
{
ProductName = "CodeChef4u ) SQL rcipies",
Price = 500,
Category = new ProductCategory()
{
CategoryName =
"Book"
},
ImageUrl = @"C:/data"
};
var
isFailed=target.ValidatePrductNameWithSpecialChar(product,out TargetMessage);
Assert.AreEqual(ExpectedErroMessage,
TargetMessage);
}
}