Tag Archives: .net

An Overview Of Unit Testing With .NET Core

In this blog on.Net Core, we shall discuss unit testing for user interface (UI). It is a topic very common, and we will see how to do it here.

An_Overview_Of_Unit_Testing_With_Dot_NET_Core

Selenium is a software-testing framework, quite portable and for web applications and there is a .NET port of it. Here we shall use the Selenium.WebDriver package, and one or more of the following, for different browsers:

Selenium.Chrome.WebDriver: for Chrome

Selenium.Firefox.WebDriver: for Firefox

Selenium.WebDriver.MicrosoftWebDriver: for IE and Edge

Selenium gives a “minimum” contract that works over all the browsers.

Here let’s discuss some examples of how it works. Let’s start with instantiating a driver:

using (var driver = (IWebDriver) new ChromeDriver(Environment.CurrentDirectory))

{

//…

}

Take note of the Environment.CurrentDirectory parameter; it marks the path where the driver can find a chromedriver.exe file, or geckodriver.exe for Firefox or MicrosoftWebDriver.exe, in case of IE/Edge. These executables get added automatically by the Nuget packages. If you don’t remove the driver, the window will remain open after the unit test finishes. You also have a choice to Quit at any time.

Let’s now navigate to some page:

driver

.Navigate()

.GoToUrl(“http://www.google.com”);

And get some element from its name:

var elm = driver.FindElement(By.Name(“q”));

Besides the name, you can also search by:

Id: By.Id

CSS class: By.ClassName

CSS selector: By.CssSelector

Tag name: By.TagName

Link text: By.LinkText

Partial link text: By.PartialLinkText

XPath: By.XPath

Once an element is found, its properties can be accessed:

var attr = elm.GetAttribute(“class”);

var css = elm.GetCssValue(“display”);

var prop = elm.GetProperty(“enabled”);

Then we can send it text strokes:

elm.SendKeys(“asp.net core”);

Or click on it:

elm.Click();

It is to be known that, page loading could take some time, so, you can configure the default time of waiting, before doing a GoToUrl:

var timeouts = driver.Manage().Timeouts();

timeouts.ImplicitWait = TimeSpan.FromSeconds(1);

timeouts.PageLoad = TimeSpan.FromSeconds(5);

ImplicitWait is only a time that Selenium awaits before searching an element.

If you have to wait for some period of time, like, till some AJAX request is done with, you can do the following:

var waitForElement = new WebDriverWait(driver, TimeSpan.FromSeconds(5));

var logo = waitForElement.Until(ExpectedConditions.ElementIsVisible(By.Id(“hplogo”)));

The condition is passed on to ExpectedConditions could be one of:

AlertIsPresent

ElementExists

ElementIsVisible

ElementSelectionStateToBe

AlertState

ElementToBeSelected

FrameToBeAvailableAndSwitchToIt

InvisibilityOfElementWithText

PresenceOfAllElementsLocatedBy

StalenessOf

TextToBePresentInElementLocated

TextToBePresentInElementValue

TitleContains

TitleIs

UrlContains

UrlMatches

UrlToBe

VisibilityOfAllElementsLocatedBy

You can see, there are several conditions that you can make use of. If the condition is not met and the timer expires, then the value returned is null.This is nice for your unit tests.

With this, we conclude.

Keep coding!

If you want to enhance yourself in basics and concepts with Dot Net Course and improve yourself through Dot NET training program; our institute, CRBtech Solutions would be of great help and support. We give a well-structured program for the best Dot Net Course. Among several good institutes of dot net training and placement in Pune, CRBtech has created a niche for itself.

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Method To Implement ListBox in Asp.Net MVC

Microsoft developed ASP.NET MVC as a web application framework which implements the model–view–controller or more popularly known as MVC pattern. It happens to be open-source software, besides the ASP.NET Web Forms component.

Method_To_Implement_List_Box_in_Asp_Dot_Net_MVC

In this blog, we shall discuss the process of implementing ListBox in asp.net MVC. Here, table “tblCity” is used for the demo.

For this demo, the “City” entity is used that is created using ADO.NET entity framework.

The first step is to generate a ViewModel class. In asp.net MVC, view models are used as techniques to transfer data between the view and the controller. Give a right click on the “Models” folder, and add a class file bearing name=CitiesViewModel.cs. Copy and paste the below mentioned code. This class will be the Model for the view.

public class CitiesViewModel

{

public IEnumerable<string> SelectedCities { get; set; }

public IEnumerable<SelectListItem> Cities { get; set; }

}

Next, right click on the folder called “Controllers” and then add a “HomeController”. Add the below two namespaces in the “HomeController”

Using MVCDemo.Models;

Using System.Text;

Copy and paste the following code.

[HttpGet]

public ActionResult Index()

{

SampleDBContext db = new SampleDBContext();

List<SelectListItem> listSelectListItems = new List<SelectListItem>();

for each (City city in db.Cities)

{

SelectListItem selectList = new SelectListItem()

{

Text = city.Name,

Value = city.ID.ToString(),

Selected = city.IsSelected

};

listSelectListItems.Add(selectList);

}

CitiesViewModel citiesViewModel = new CitiesViewModel()

{

Cities = listSelectListItems

};

return View(citiesViewModel);

}

[HttpPost]

public string Index(IEnumerable<string> selectedCities)

{

if (selectedCities == null)

{

return “No cities selected”;

}

else

{

StringBuilder sb = new StringBuilder();

sb.Append(“You selected – ” + string.Join(“,”, selectedCities));

return sb.ToString();

}

}

Next give a Right click on the method called “Index” action in “HomeController” and choose “Add View” from the context menu. Set

View Name = Index

View Engine = Razor

Then click “Add”.

Copy and paste the below mentioned code in “Index.cshtml”

@model MVCDemo.Models.CitiesViewModel

@{

ViewBag.Title = “Index”;

}

<div style=”font-family:Arial”>

<h2>Index</h2>

@using (Html.BeginForm())

{

@Html.ListBoxFor(m => m.SelectedCities, Model.Cities, new { size = 4 })

<br />

<input type=”submit” value=”Submit” />

}

</div>

To note that, if you want to select multiple items from the list box, you have to hold down the CTRL Key.

Keep coding!

If you want to enhance yourself in Dot Net Course and improve yourself through Dot NET training program; our institute, CRBtech Solutions would be of great help and support. We give a well-structured program for the best Dot Net Course. Among many reputed institutes of dot net training and placement in Pune, CRBtech has created a niche for itself.

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Know About The MiniBlog.Core Built Using ASP.NET Core 2.0

Are you aware of the MiniBlog.Core? Well, to mention it is a new and powerful blog platform built on ASP.NET Core 2.0 and offers an excellent reading experience on every device. It has the best practices for web development, which includes best-in-class performance, readability, accessibility, SEO, social web integration with the help of a mobile-first strategy.

Know About The MiniBlog.Core Built Using ASP DOT NET Core 2.0

Building Miniblog.Core

One who designed the blog wanted to design a blog engine based on ASP.NET Core that takes every advantage of modern browsers to develop the best possible experience for both the visitors and authors. To achieve that, the blog must load very fast, offer a great reading experience, appear amazing on every type of devices and handle every technical stuff like social media integration and SEO automatically.

Web fonts

To select the right font is essential to offer a good experience for the readers. For that, you need to use a custom web font which is being loaded and used by CSS. The problem with custom web fonts is that the browser has to download them followed by a slow mobile connection.

Instead, its maker wanted to apply fonts which are built on various browsers to offer the same high-quality reading experience but without any extra file downloads.

Image optimization

An extension for image optimisation for Visual Studio is used for years to optimize the images in the web projects. That is good for images up front, but what about those being uploaded by the users as part of blog posts? How to optimise the images, on the production server while they get uploaded.

As there are no .NET Core libraries which can optimize images as well as the Image Optimizer extension, so an Azure Web job is created. This contains the exact and same optimization algorithms as the extension and enveloped it in a NuGet package.

It’s named as Azure Image Optimizer and works by adding it to an ASP.NET project without any extra steps. When an ASP.NET app gets published to Azure, the NuGet package would add a Web job to the publish output which automatically starts up and supervises image files once it reaches Azure. It leaves no artifacts in the project and doesn’t need any code changes, only add NuGet package and deploy to Azure.

Content delivery network (CDN)

And the advantage of CDNs has been taken to make sure that the blog can be optimized as desired, to adress all the static files like the JavaScript, CSS, and images. You need to use WebEssentials.AspNetCore.CdnTagHelpers Nuget package :

{

“cdn”: {

“url”: “https://myname.azureedge.net”

}

}

Sass, bundling, and minification

Since Sass has been used instead of plain old CSS it had to be compiled. The maker decided to go with a much simpler approach which is LigerShark WebOptimizer.Core and LigerShark.web optimizer.Sass NuGet packages.

With the use of those packages, you get runtime and build time asset pipeline management with almost no code. The only thing required is to register the service and middleware in Startup.cs so:

services.AddWebOptimizer(pipeline =>

{

pipeline.MinifyJsFiles();

pipeline.CompileScssFiles()

.InlineImages();

});

That will automatically compile the Sass files into CSS and minimise the JavaScript files. No additional code or artifacts are needed.

A Checklist

Like any website, this provides the best practices outlined by the Web Developer Checklist which includes many automated tests which run in the browser and a list of highly useful tools in Miniblog’s Technical Features section.

So here we conclude with this discussing the new Miniblog.Core. 

Keep coding!

If you want to enhance yourself in Dot Net Course and improve yourself through Dot NET training program; our institute, CRBtech Solutions would be of great help and support. We give a well-structured program for the best Dot Net Course. Among many reputed institutes of dot net training and placement in Pune, CRB Tech has created a niche for itself.

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How C# 7.1 Is Different?

With C#, Microsoft has been always some major releases: with a lot of features up, and less frequent release. They went ahead than routinely, omitting the conventional “.0″ when they talked about C# 6.0!

C# 7.1

In the C# 7.0, they are trying something innovative. Tools like Visual Studio upgrade in a frequent mode and they left no reason why the C# couldn’t also be updated more frequently. Hence this time, they are embracing a notion of “point releases”; minor versions of C# with quite useful but smaller language features and with shorter intervals. This indicates that you don’t need to wait for a long time to make some additional value to ship, but also it becomes easy to align a C# release with the shipping of related features, e.g. in.NET.

It is a fact that upgrading to a newer version of programming language every time could be a hassle in an organization and is not the way for everyone. Visual Studio 2017 allows you to decide whether to take the latest or only to the major (“.0″) versions of C#. You can choose your own rhythm.

The first point release

In August of 2017 Microsoft shipped the first point release of C# and named as C# 7.1, and its main purpose is to get practice with point releases, without too many dependencies on accompanying technology to make things complicated.

C# 7.1 is a small release with just a few and well-chosen new language attributes but in the minor range. It’s supported by VS 2017, starting with Update 15.3.

Let’s take a look! There is a program which uses the three C# 7.1 features that are being covered here, and a number of the recent C# 7.0 ones.

using System.Linq;

using System.Threading;

using System.Threading.Tasks;

using static System.Console;

class Program

{

static async Task Main(string[] args)

{

var results = Enumerable.Range(1, 40)

.Select(input => (input, task: FibonacciAsync(input)))

.ToArray();

for each (var tuple in results)

{

WriteLine($”Fib {tuple.input} = {await tuple.task}”);

}

}

private static Task<int> FibonacciAsync(int n, CancellationToken token = default)

{

return Task.Run(() => Fib(n).curr, token);

(int curr, int prev) Fib(int i)

{

if (i is 0) return (1, 0);

var (c, p) = Fib(i – 1);

return (c + p, c);

}

}

}

view raw

cs7.1-Example.cs hosted with by GitHub

It figures out the first 40 Fibonacci numbers in parallel on the thread pool and prints them out in order.

Here let’s take a look at C# 7.1 features used here.

Async Main

The Main entry point method can return a Task or a Task<int>. And as a result, execution will wait for the returned task to complete, before shutting down the program.

The main purpose is to make the Main method async, which you can do as well:

static async Task Main(string[] args)

This makes you wait for the Main method, which you couldn’t do before.

WriteLine($”Fib {tuple.input} = {await tuple.task}”);

Previously what you need to do was that, first you’d create an async helper method, for instance, MainAsync, with all the logic in. Then you can write this cryptic Main method:

static void Main(string[] args) => MainAsync().GetAwaiter().GetResult();

Now you can asynce the Main method and the compiler would rewrite it for you.

Inferred tuple element names

In lambda expression in the query:

input => (input, task: FibonacciAsync(input))

Only a tuple is created, and give a name, task, for the second element. And a few lines later you are able to say

WriteLine($”Fib {tuple.input} = {await tuple.task}”);

To access the first element with the name tuple.input.

Default literals

With an expected type for a default expression, you can omit the mention of the type, as done for the CancellationToken in the signature of the FibonacciAsync method:

Private static Task<int> FibonacciAsync(int n, CancellationToken token = default)

This prevents a repetition of type names or typing the longer ones which are already given by context.

Microsoft is already working on C# 7.2, and also the features intended for their next major release.

With this, we conclude.

Happy coding!

If you want to enhance yourself in Dot Net Course and improve yourself through Dot NET training program; our institute, CRBtech Solutions would be of great help and support. We give a well-structured program for the best Dot Net Course. Among many reputed institutes of dot net training and placement in Pune, CRB Tech has created a niche for itself.

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12 Online C# Tutorials For 2018

Are you a beginner developer or someone who’s keen to learn programming languages? To mention, C# is great for learning. Unlike C++, for example, C# provides automatic memory management, and it also offers solid Type Safety in comparison to JavaScript and node.js. C# has huge libraries of base class; the .NET framework has several hundreds of libraries to work with the file system, manage security, and much more.

12 Online C# Tutorials For 2018

With the release of .NET Core, it appears that C# and .NET Core would be in a huge demand in 2018.

Whether you are learning C# for the first time or enhancing your C# expertise, here we share with you 12 best tutorials for both the beginners and experienced programmers to enrich their knowledge.

12 of the Best C# Tutorials

1. Lynda.com

Their topics include core language elements like data types, variables, and constants. There are 5 challenge videos which let you test yourself, along with another 5 videos with explained answers.

Key Topics:

To work with loops

To builds functions

To catch errors

To manage resources with t garbage collector

2. C# Station

They have a set of lessons for a beginner to intermediate-level developers.

Key Topics:

Expressions, Types, and Variables

Namespaces

Overview of Classes

Indexers and Attributes

To work with Nullable types

3. Tutorials Teacher

This site features free online tutorials on web technology for the beginners and professionals alike. In addition to C#, they teach ASP.NET MVC, LINQ, jQuery, AngularJS, JavaScript, or Node.js.

Key Topics:

Data types, classes, and variables

Switches and loops

Strings and arrays

Stream I/O

4. Deccansoft

Every concept is explained in details using different walkthroughs and practical methods. It is recommended to have a practical knowledge of any one programming language before you go for this course.

Key Topics:

.NET Framework

Common Language Runtime concepts

To build a standard GUI for Windows-based applications with the use of WinForms.

5. edX

This tutorial originates from edX, an online educational services provider which offers some courses to top universities and colleges. This is not a starter’s course and needs you to have a prior understanding of the programming language.

Key Topics:

C# syntax

Fundamentals of C# language

Object-oriented programming

Overview of .NET Framework

6. Udemy

This happens to be one of the largest online educational platforms with thousands of courses. There are many video tutorials on C# programming, but the best ones aren’t free and charge a reasonable fee.

Key Topics:

Loops, arrays, and structures

Coding beginner projects

To make the right approach

7. LearnCS.org

A free online tutorial for C#; the website is dedicated exclusively to teaching C#.

Key Topics:

Variables and types

Strings, and loops

Methods

Classes and class properties

8. Microsoft Virtual Academy

This C# tutorial offers 24 practical and easy episodes. Besides the fundamentals of C#, this course also covers the tools, tips to write code, debug features, explore customizations, and much more.

Key Topics:

To create and understand C# program

Understand Data types and Variables

Understand Arrays

Work with Strings

Learn to work with Date and Time data

9. Abbot – C# Tutorial

They have tutorials which cover the basics like loops, strings, and arrays and then offers more complicated stuff like delegates, namespaces, and collections.

Key Topics:

Data types

Lexical structure

Strings

Flow control

Delegates

Namespaces

Collections

10. Channel 9

With their “Jump Start” program they provide every topic with examples.

Key Topics:

Introduction to oriented programming

Basics of a managed language

Why C# is best for OOP

C# Syntax

11. SoloLearn

Their tutorials are fun and teach C# concepts through short interactive texts, games, and quizzes. The instructors offer a hands-on approach and that is the best way to learn codes and practicing them.

Key topics:

Basic concepts like variables, printing, and arithmetic operators

Loops and methods

Arrays and strings

Inheritance, polymorphism, and generics

12. Microsoft – Getting started with C#

This is a nice little tutorial from Microsoft and is unique and tailored. You can select your degree of difficulty before you begin with selecting if you are a beginner or experienced.

Key Topics:

Write your first hello world program

Strings, loops, dates, and times

Arrays, collections, and calling methods

Namespaces

Test your code and troubleshooting

Besides the above mentions, there are some other websites offering C# courses online like Coursera – Beginning Game Programming with C#, 26. Certification Guru – C# .NET Programming, Complete C# Tutorial just to name a few.

Once you’ve become an expert at C#, you can need to check out other resources with an advanced tutorial.

With this, we conclude.

Keep coding!

If you want to enhance yourself in Dot Net Course and improve yourself through Dot NET training program; our institute, CRB Tech Solutions would be of great help and support. We give a well-structured program for the best Dot Net Course. Among many reputed institutes of dot net training and placement in Pune.

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How Can .NET Core 2.0 Act As Saviour When there is Dot NET Core DLL Hell

If you know that .NET came with a promise, about 15 years ago to eliminate DLL hell. It was then a big issue to register COM DLL files. And today with mixing, NET Standard, .NET Core and .NET Framework projects have created a new DLL hell.

Can .NET Core 2.0 Act As Saviour When there is Dot NET Core DLL Hell

Here let’s discuss a DLL hell problem.

Suppose there is a simple NetStandard library with some simple classes in it that are used by an ASP.NET Core MVC app and a .NET Framework console application.

There is also System.IO 4.3.0, the latest version.

Other Class Library

In a console app, there is a bunch of classes and business logic. And it is kept in a separate class library. This .NET Framework library also references the CoreLibrary project which is.NETStandard 1.5. And the problem starts, where there are several wonderful messages like this for basic system DLLs.

2> Consider app.config to remap of assembly “System.IO, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a” from Version “4.1.1.0” [] to Version “4.1.2.0” [C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\MSBuild\Microsoft\Microsoft.NET.Build.Extensions\\net461\ref\System.IO.dll] to solve conflict and get rid of warning.

2>C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\MSBuild\15.0\Bin\Microsoft.Common.CurrentVersion.targets(2099,5): warning MSB3836: The explicit binding redirect on “System.IO, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a” conflicts with an auto-generated binding re-direct. You need to remove it from the application configuration file or disable autogenerated binding redirects. The build will replace it with: “<bindingRedirect oldVersion=”0.0.0.0-4.1.2.0″ newVersion=”4.1.2.0″ xmlns=”urn: schemas-Microsoft-com:asm.v1″ />”.

DLL Version Hell

The .NETStandard class library uses System.IO 4.3.0, and so also the Framework class library.

<Reference Include=”System.IO, Version=4.1.1.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL”>

<HintPath>..\packages\System.IO.4.3.0\lib\net462\System.IO.dll</HintPath>

</Reference>

Then… why the DLL hell there are errors about 4.1.1 and 4.1.2?

It could be that the System.IO 4.3.0 package has different version DLLs in it? You need to recheck. And on looking into the System.IO.dll that gets copied to the bin folder after a build… it says 4.6.24705.1, just like the one in “..\packages\System.IO.4.3.0\lib\net462\System.IO.dll”.

And this is a real cruel deal. Who’s on first? What’s on second?

Why there are 4 Versions of the Same DLL/Package?

Let’s recap; there were versions 4.1.1, 4.1.2, 4.3.0, and 4.6.24705.1. Except, the only one which is actually seen is v4.6 stuck in a v4.3 folder. But why it shows 4.1.1 and 4.1.2 build errors.

Does it make any sense?

Why the .NET team has a v4.6 dll in a v4.3 NuGet package which is really v4.1.1.

It could be the effect of mixing.NETStandard and .NET Framework projects together are the problem.

How .NET Core 2.0 helps?

With the emergence of .NET Core 2.0, you need to switch all the projects. Initially, you were made to use full .NET Framework due to a few NuGet packages that were unavailable for NetStandard.

The false support for .NET Framework packages from a .NET Core application seems an easy solution.

Summary

With different projects that reference each other with conflicts in dependencies, it becomes complicated. The complexity of working with.NET Framework, netcoreapp, and.NETStandard all together is really complicated.

We can hope that .NET Core 2.0 solves the current set of issues.

With this, we conclude. This blog is an adaptation of a blog in Stackify. Keep coding!

If you want to enhance yourself in Dot Net Course and improve yourself through Dot NET training program; our institute, CRB Tech Solutions would be of great help and support. We give a well-structured program for the best Dot Net Course. Among many reputed institutes in Pune, CRB Tech has created a niche for itself.

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New SPA Templates With ASP.NET Core 2

With the introduction of ASP.NET Core 2 Preview 2, now there are new web application templates present for Single Page Applications or SPA. Presently Angular, React.js, and React.js + Redux are supported. The intention of this blog post is to provide a short overview of the new templates and related applications as a sample.

New SPA Templates With ASP DOT NET Core 2

New SPA templates

While creating new ASP.NET Core application using Visual Studio 2017 Preview 3 there are three new templates for SPA.

The three templates actually create the same sample application but where they differ is in the JavaScript libraries. To mention, these new templates are found only when ASP.NET Core 2 is selected from framework dropdown list on top of the dialog.

TypeScript and webpack

SPA-s have ClientApp folder where JavaScript framework components are kept.

Another new aspect is a support for webpack module bundler. Webpack is added to the project as Node.js module. It is irrelevant as Task Runner. Webpack is run as a part of the build. It takes care of bundling and minimisation as well.

Webpack publishes bundled and minimised files to wwwroot\dist folder when the application is built. JavaScript libraries are piled to file wwwroot\dist\vendor.js and styles that come with these libraries are packet to wwwroot\dist\vendor.css file. Both files are minimised automatically as well.

webpack.config.js is a configuration file for webpack where all piling and minimising rules are defined. You can also add your own rules there.

Sample application

Let’s consider a SPA sample application which demonstrates simple counter and weather forecast page. The counter page uses JavaScript and forecast page uses server call to get weather forecasts. There is SampleDataController where sample data is produced.

Conclusion

The new SPA templates are very simple but potential as most of the work including scripts and adding components is done and to start building your own application become quite easy. Developers coding SPA-s on ASP.NET Core must know well the webpack as it is also one of most popular packing tools in JavaScript world.

With this, we conclude. Keep coding!

If you want to enhance yourself in Dot Net and improve yourself through Dot NET training program; our institute, CRB Tech Solutions would be of great help and support. We offer a well-structured program for the best Dot Net Training Course.

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How To Test Logging In ASP.NET Core

In some cases, like analysis of problems in production, logging is really essential. Even you would like to test that your logging really works.

Testing_Logging_In_ASP_DOT_NET_Core

Let’s take the following function:

Public void DoSomething(int input)

{

_logger.LogInformation(“Doing something…”);

try

{

// do something that might result in an exception

var result = 10 / input;

}

catch (Exception ex)

{

// swallow but log the exception

_logger.LogError(ex, “An error occurred doing something.”, input);

}

public void DoSomething(int input)

{

_logger.LogInformation(“Doing something…”);

try

{

// do something that might result in an exception

var result = 10 / input;

}

catch (Exception ex)

{

// swallow but log the exception

_logger.LogError(ex, “An error occurred doing something.”, input);

}

}

We can assume that with an occurrence of this exception, it’s costing the company good amount of money. Hence it is good to know about it to solve a problem. From a developer’s point of view, the LogError method has the business Importance. And to be sure about it’s working right, there must be automated tests.

Now, consider how to test this code when the _logger case in question is an ASP.NET Core ILogger<T> type, input like as it is:

public class SomeService

{

private readonly ILogger<SomeService> _logger;

public SomeService(ILogger<SomeService> logger)

{

_logger = logger;

}

// methods

}

public class SomeService

{

private readonly ILogger<SomeService> _logger;

public SomeService(ILogger<SomeService> logger)

{

_logger = logger;

}

// methods

}

Now the question is how to test this scenario! You can’t call the method and then observe SomeService’s state to see if it is working. The only way to confirm in a unit test is to pass in your own implementation of ILogger<SomeService> into SomeService, and then find out if this instance was called by the DoSomething method. One way to do this is to use a mocking library like Moq, as shown below:

public void LogsErrorWhenInputIsZero()

{

var mockLogger = new Mock<ILogger<SomeService>>();

var someService = new SomeService(mockLogger.Object);

someService.DoSomething(0);

// Option 1: Try to verify the actual code that was called.

// Doesn’t work.

mockLogger.Verify(l => l.LogError(It.IsAny<Exception>(), It.IsAny<string>(), 0));

}

public void LogsErrorWhenInputIsZero()

{

var mockLogger = new Mock<ILogger<SomeService>>();

var someService = new SomeService(mockLogger.Object);

someService.DoSomething(0);

// Option 1: Try to verify the actual code that was called.

// Doesn’t work.

mockLogger.Verify(l => l.LogError(It.IsAny<Exception>(), It.IsAny<string>(), 0));

}

To mention, this approach fails as there is no LogError method on ILogger<T>, which is the LoggerExtension. This is the main reason why unit testing logging is difficult in ASP.NET Core.

A solution to this is to open a code for the logger extensions and find out what non-extension method is finally executed on ILogger. This would lead to a test like this one:

public void LogsErrorWhenInputIsZeroTake2()

{

var mockLogger = new Mock<ILogger<SomeService>>();

var someService = new SomeService(mockLogger.Object);

someService.DoSomething(0);

// Option 2: Look up what instance method the extension method actually calls:

//https://github.com/aspnet/Logging/blob/dev/src/Microsoft.Extensions.Logging.Abstractions/LoggerExtensions.cs#L342

// Mock the underlying call instead.

// Works but is ugly and brittle

mockLogger.Verify(l => l.Log(LogLevel.Error, 0, It.IsAny<FormattedLogValues>(), It.IsAny<Exception>(),

It.IsAny<Func<object, Exception, string>>()));

}

public void LogsErrorWhenInputIsZeroTake2()

{

var mockLogger = new Mock<ILogger<SomeService>>();

var someService = new SomeService(mockLogger.Object);

someService.DoSomething(0);

// Option 2: Look up what instance method the extension method actually calls:

// https://github.com/aspnet/Logging/blob/dev/src/Microsoft.Extensions.Logging.Abstractions/LoggerExtensions.cs#L342

// Mock the underlying call instead.

// Works but is ugly and brittle

mockLogger.Verify(l => l.Log(LogLevel.Error, 0, It.IsAny<FormattedLogValues>(), It.IsAny<Exception>(),

It.IsAny<Func<object, Exception, string>>()));

}

But you might have to mock calls that don’t even exist in the method we’re testing.

But every problem has a solution finder. So finally a trouble-shooter solved it by mentioning the need to create own version of ILogger<T> and give it with its own implementation of the method that has to be checked.

As instance methods are used before extensions methods, this would rather override the extension method in the test code. Thus, will appear the implementation:

public void LogsErrorWhenInputIsZeroTake3()

{

var fakeLogger = new FakeLogger();

var someService = new SomeService(fakeLogger);

someService.DoSomething(0);

// Option 3: Create your own instance of ILogger<T> that has a non-extension version of the method

// Doesn’t work, unless you change system under test to take in a FakeLogger (which is useless)

Assert.NotNull(FakeLogger.ProvidedException);

Assert.NotNull(FakeLogger.ProvidedMessage);

}

private class FakeLogger : ILogger<SomeService>

{

public static Exception ProvidedException { get; set; }

public static string ProvidedMessage { get; set; }

public static object[] ProvidedArgs { get; set; }

public IDisposable BeginScope<TState>(TState state)

{

return null;

}

public bool IsEnabled(LogLevel logLevel)

{

return true;

}

public void Log<TState>(LogLevel, EventId, TState state, Exception, Func<TState, Exception, string> formatter)

{

}

public void LogError(Exception ex, string message, params object[] args)

{

ProvidedException = ex;

ProvidedMessage = message;

ProvidedArgs = args;

}

}

public void LogsErrorWhenInputIsZeroTake3()

{

var fakeLogger = new FakeLogger();

var someService = new SomeService(fakeLogger);

someService.DoSomething(0);

// Option 3: Create your own instance of ILogger<T> that has a non-extension version of the method

// Doesn’t work, unless you change system under test to take in a FakeLogger (which is useless)

Assert.NotNull(FakeLogger.ProvidedException);

Assert.NotNull(FakeLogger.ProvidedMessage);

}

private class FakeLogger : ILogger<SomeService>

{

public static Exception ProvidedException { get; set; }

public static string ProvidedMessage { get; set; }

public static object[] ProvidedArgs { get; set; }

public IDisposable BeginScope<TState>(TState state)

{

return null;

}

public bool IsEnabled(LogLevel logLevel)

{

return true;

}

public void Log<TState>(LogLevel logLevel, EventId eventId, TState state, Exception, Func<TState, Exception, string> formatter)

{

}

public void LogError(Exception ex, string message, params object[] args)

{

ProvidedException = ex;

ProvidedMessage = message;

ProvidedArgs = args;

}

}

Even now you could assume that DoSomething is still calling the method LogError on ILogger<T>, Yet the extension method will be used because ILogger<T> doesn’t have an instance method that it could match. The only solution is to change the SomeService method to accept a FakeLogger, instead of an ILogger<T>, but even that doesn’t come as a real solution.

So what could be done?

The actual problem is we are dependent on types which are outside our control, and the types are using static methods which can’t be decoupled in tests. To attain loose coupling in our applications, we have to bring together dependencies on specific implementations by working with interfaces that can be controlled. This is a segment of the Interface Segregation Principle (ISP).

Now, some developers will counter because it’s not an implementation and even its part of the framework that we depend upon. But to accept the fact that, ILogger<T> isn’t an implementation, it’s only a use of extension methods and makes testing difficult. The best way to address the problem is with the use of an adapter.

You can start with the minimal interface which your client code needs. You don’t need to create one adapter for all but with every variation of method found on LoggerExtensions. Most applications won’t need all of them, so include the ones you require.

public interface ILoggerAdapter<T>

{

// add just the logger methods your app uses

void LogInformation(string message);

void LogError(Exception ex, string message, params object[] args);

}

public interface ILoggerAdapter<T>

{

// add just the logger methods your app uses

void LogInformation(string message);

void LogError(Exception ex, string message, params object[] args);

}

You can implement the adapter easily by passing in the implementation type it’s using. In this case, the ILogger<T> type and its extension methods:

public class LoggerAdapter<T> : ILoggerAdapter<T>

{

private readonly ILogger<T> _logger;

public LoggerAdapter(ILogger<T> logger)

{

_logger = logger;

}

public void LogError(Exception ex, string message, params object[] args)

{

_logger.LogError(ex, message, args);

}

public void LogInformation(string message)

{

_logger.LogInformation(message);

}

}

public class LoggerAdapter<T> : ILoggerAdapter<T>

{

private readonly ILogger<T> _logger;

public LoggerAdapter(ILogger<T> logger)

{

_logger = logger;

}

public void LogError(Exception ex, string message, params object[] args)

{

_logger.LogError(ex, message, args);

}

public void LogInformation(string message)

{

_logger.LogInformation(message);

}

}

At this point, you refract your service to remove the ILogger<T> dependency and instead use an ILoggerAdapter<T>. And next writing a text to verify that the error is logged properly becomes easy:

public void LogsErrorWhenInputIsZero()

{

var mockLogger = new Mock<ILoggerAdapter<SomeOtherService>>();

var someOtherService = new SomeOtherService(mockLogger.Object);

someOtherService.DoSomething(0);

mockLogger.Verify(l => l.LogError(It.IsAny<Exception>(), It.IsAny<string>(), 0));

}

public void LogsErrorWhenInputIsZero()

{

var mockLogger = new Mock<ILoggerAdapter<SomeOtherService>>();

var someOtherService = new SomeOtherService(mockLogger.Object);

someOtherService.DoSomething(0);

mockLogger.Verify(l => l.LogError(It.IsAny<Exception>(), It.IsAny<string>(), 0));

}

With this we conclude.

Keep coding!

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9 Things To Know Before Converting ASP.NET To .NET Core

During the conversion of ASP.Net to.Net Core, there are certain things you should know and understand. Here we listed the nine things you must know before you convert from ASP.NET to .NET Core.

9 Things To Know Before Converting ASP.NET to .NET Core

1. Build to deploy

If you want to create an app that targets non-Windows, you need to build it on the target platform. Rather you can’t create your app on Windows and next deploy it to a Mac. You can perform that with a net standard library, but not a netcoreapp. Hope this limitation is overcome in future.

2. IIS is somewhat dead

Microsoft created a new web server called Kestrel. IIS is amazing but comes with a very dated limited model and carries lots of weight with it.

Kestrel makes deploying the web app easily like deploying any console app. When ASP.NET Core app starts, it activates Kestrel server, sets up HTTP bindings, and handles everything.

IIS isn’t dead in actual. IIS can be used as a reverse proxy sitting in front of Kestrel to take advantage of some of its features that Kestrel doesn’t have, like virtual hosts, security, logging, etc. Microsoft yet suggests using IIS to remain in front of ASP.NET Core apps.

3. HttpModules and HttpHandlers are substituted by a middleware

Middleware is created to replace modules and handlers. The mixed news is that you can’t configure them in a config file. They are all mentioned in the code.

4. To use xproj & csproj files together

In no way, the two project types refer each other. You move everything of xproj, but no longer could use MSBuild. But it is possible to use xproj and csproj files both at the same time while doing your Windows targeted the creation of Prefix.

5. StreamReader constructor doesn’t work with a file path

Previously StreamReader was often used by sending a file path to the constructor. Now you have to send a stream. This cause little refactorings to use a FileStream in addition to the StreamReader everywhere.

6. Platform-specific code… like Microsoft specific RSA

.NET Core is created to run on Windows, Linux, and Macs. But some codes can compile on Windows but then fail during runtime while you want to run on a Mac or Linux. For example, RSACryptoServiceProvider which seems efficient. At Mac runtime, a message will pop up “platform not supported”. To know, RSA provider API is Windows specific. Instead, you need to use RSA.Create() which has slightly different methods.

7. No existence of System.Drawing

If you want to resize images, then you can’t-do currently with .NET framework. There are a few projects which could be used.

8. Web API is Gone

With .NET Core, Microsoft decided to merge together Web API and MVC. They were very similar to work with and either was used for API type applications. Hence in a several ways, merging them makes sense.

9. To design Windows Service in .NET Core

Windows Services can be created with VS 2017 so long the code targets the .NET Framework. You have to move your .NET Core code to a class library which targets NetStandard that could then be shared through different .NET Core apps and your Windows Service.

Keep coding!!

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Stay connected to CRB Tech for your technical up-gradation and to remain updated with all the happenings in the world of Dot Net.

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Ways To Configure log4net For .NET Core

We start with the mention that the log4net team published new NuGet packages which support.NETStandard 1.3, which says it must work with .NET Core. This article is to discuss updates for log4net support.

Ways To Configure log4net For Dot NET Core

To start with: Configure() log4net

To add a reference to the log4net NuGet package is no problem. If you worked previously with log4net for any amount of time, you know that you must add codes for configuring it.

XmlConfigurator.Configure() needs some parameters that we didn’t usually provide in the past.

Configuration Workaround: Load It Manually

This log4net is good enough to load its configuration from a web.config or log4net.config file. In .NET Core, it doesn’t appear to know how.

It makes sense that this can’t read from a web.config/app.config because they don’t exist in .NET Core.

But, it doesn’t automatically try to read a log4net.config file. To mention, NLog does the same thing. You need to configure manually as in .NET Core.

With little little reverse dtudying, you will know how to load the log4net.config file and configure log4net.

var logRepository = LogManager.GetRepository(Assembly.GetEntryAssembly());

XmlConfigurator.Configure(logRepository, new FileInfo(“log4net.config”));

You can get this to work with a .NET Core app targeting both netcoreapp1.0 and net452. Sum up that to your Program.cs as the first thing your code does.

There is a mention about some limitations with the current 2.0.7 version of log4net. Hopefully, there will be some more developments.

Now with this, we conclude. We hope this was of help to you.

If you want to enhance yourself in Dot Net Course and improve yourself then our institute, CRB Tech Solutions would be of great help and support.

They offer a well-structured program for the best Dot Net Training course. Among many reputed institutes of dot net training and placement in Pune. Keep coding!!

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