Luke Warren Dev
Software Development Tips and Stories When I feel Like It

CI and CD Pipeline for Rework

My first YouTube Video

CI and CD Pipeline for Rework

Short post here.

Just wanted to notify my loyal reader base of a YouTube video that I have put up showing how the continuous integration and continuous delivery pipeline works for Rework. The video was filmed via live stream on my LiveCoding.tv channel but I also uploaded it to YouTube

So, without further adieu:



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Your Code Sucks and Other Political Statements

There is no secret sauce or trick you haven't got around to learning to start unit testing. Your code just sucks

Your Code Sucks and Other Political Statements

OK I have got your attention. Good!

There are too many devs going around that think that unit testing was some dark art that they never learned, a waste of time or they just need some of that special sauce. Sorry folks but the reality is that unit testing is not the problem, it is your code.

With that said, do not fret! I this article I will show you a few simple tricks to get from sucky code to ... erm.. not sucky code?

Anyway, let's start with a snippet:

This code is based on a certain politician in South Africa. For non-saffas, he owed some money and needed to pay it back.

using PayBackTheMoney.Services;
using System;

namespace PayBackTheMoney
{
    public class Payer
    {
        public bool TryPayMoney(DateTime timeToPayBackTheMoney, bool canDelayProcess)
        {
            if (!canDelayProcess && DateTime.Now >= timeToPayBackTheMoney)
            {
                // Damn, have to pay
                var payer = new MoneyPayerService();
                payer.Pay(7000000M);

                // Send Thuli email
                var notifications = new NotificationService();
                notifications.Send("jacob@anc.gov.za", "thuli@madonsela.gov.za", "I pay bak moneyies.\r\n Love, Jacob");
                return true;
            }

            // "HA HA HA! "Nkandla"" HA HA HA
            return false;
        }
    }
}

Think the above code is good? It isn't. Think it is unit testable? You guessed it, it isn't!

Why? A unit test by its very definition is a method that tests a very small piece of logic in isolation. It should not rely on it's dependencies to be operational and in a certain state to be tested. Those are called integration tests.

The above is littered with concrete dependencies which makes it impossible to unit test.

Have a look again at the code. This time I have commented every issue:

using PayBackTheMoney.Services;
using System;

namespace PayBackTheMoney
{
    public class Payer
    {
        public bool TryPayMoney(DateTime timeToPayBackTheMoney, bool canDelayProcess)
        {
            // We are relying on the DateTime.Now property to return the current DateTime from the system clock
            // To test this we would need to set the clock on the PC we are using every time we want to test. What a pain!
            if (!canDelayProcess && DateTime.Now >= timeToPayBackTheMoney)
            {
                // We are using the new keyword to create an instance of our money payer service. This means that we have a concrete dependency on this class
                // Who knows what the money payer service might be dependent on to perform its "duties".
                var payer = new MoneyPayerService();
                payer.Pay(7000000M);

                // Again, as above. Newing up the NotificationService ties us to it and means that we can't test this method in isolation from its dependencies
                // Point is, we can't swap it out with a fake in our test code. We would have to make sure that an SMTP server was running!
                var notifications = new NotificationService();
                notifications.Send("jacob@anc.gov.za", "thuli@madonsela.gov.za", "I pay bak moneyies.\r\n Love, Jacob");
                return true;
            }

            return false;
        }
    }
}

As you can see, this code is using the new keyword to create services that it needs to use. This is a massive issue when it comes to unit testing because to test the Payer method you need to have both an operational NotificationService, MoneyPayerService and you would need to set your computer's clock to a new date every time you needed to test under that particular instant in time. Hear that? Those are alarm bells ringing in your ears.

Don't worry dear reader, you are not completely stuffed. We can actually very easily fix this code. Simply put, we need to make our Payer class rely on abstractions rather than concretions. This means creating interfaces to describe what each of our dependencies need to do. I like to refer to them as contracts and they will act sort of like base classes.

Interfaces are like an abstract class, except they have absolutely no implementation. Like an abstract class though, classes can inherit from them and we can then use polymorphism to handle calling the right method at the right time.

Lets now look at our fixed up class:

using DecoupledPayBackTheMoney.Contracts;
using DecoupledPayBackTheMoney.Services;
using System;

namespace DecoupledPayBackTheMoney
{
    public class Payer
    {
        private readonly IMoneyPayerService _payer;
        private readonly INotificationService _notificationService;
        private readonly IDateTimeProvider _dateTimeProvider;

        /// <summary>
        /// The pattern of injecting your dependecies via the constructor like this is called the "strategy pattern"
        /// </summary>
        public Payer(
            IMoneyPayerService payer,
            INotificationService notificationService,
            IDateTimeProvider dateTimeProvider)
        {
            _payer = payer;
            _notificationService = notificationService;
            _dateTimeProvider = dateTimeProvider;
        }

        /// <summary>
        /// Lazy-man's Dependency Injection
        ///
        /// This is our public parameterless constructor. It takes care of passing in our concrete implementations.
        ///
        /// Ideally you would be using IoC framework for this like Ninject or AutoFac
        /// </summary>
        public Payer()
            : this(new MoneyPayerService(),
                  new NotificationService(),
                  new DateTimeProvider())
        {
        }

        public bool TryPayMoney(DateTime timeToPayBackTheMoney, bool canDelayProcess)
        {
            DateTime now = _dateTimeProvider.GetCurrentDateTime();
            if (!canDelayProcess && timeToPayBackTheMoney <= now)
            {
                // Damn, have to pay
                _payer.Pay(7000000M);

                // Send Thuli email
                _notificationService.Send("jacob@anc.gov.za", "thuli@madonsela.gov.za", "I pay bak moneyies.\r\n Love, Jacob");
                return true;
            }

            // "HA HA HA! "Nkandla"" HA HA HA
            return false;
        }
    }
}

Things to note:

  • We have defined interfaces for each of our dependencies.
  • Each of our services in turn inherit from these interfaces.
  • This means that our services HAVE to implement the methods defined in the interfaces.
  • Our class now relies on these abstractions rather than concretions
  • We inject our dependencies via the constructor using what is called the strategy pattern
  • Instead of needing proper versions of each of our services to test, we could now pass some fake versions of these services which do not rely on things like the system clock or a mail server
  • We can now unit test our payer class!

Note: For simplicity, we are using what is known as "poor man's dependency injection". Ideally you would rather use an inversion of control framework like Ninject or AutoFac to handle this for you so that you are even more loosely coupled.

The full source code of both the rubbish code and the better decoupled code can be found on Github. Poke around and if you have any questions leave a comment below.

Image used is from The South Africa http://www.thesouthafrican.com/jacob-zuma-announces-his-resignation-cabinet-left-jobless/


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Introducing the Model Builder - You Don't Need Automapper

This post is quite simple. You don't need Automapper, all you need is a model builder.

Introducing the Model Builder - You Don't Need Automapper

Now I am a big fan of "don't reinvent the wheel" but at times we as developers need to learn where to draw the line. In this article I will show you a very simple pattern that gives you more control and avoids needing to bring in yet another dependency - AutoMapper.

Disclaimer: I like and use Automapper in many of my projects and will continue to. It is a great library but sometimes you just don't need it.

Example ModelBuilder

All our model builder class does is either create a Model class from its entity/domain class equivalent OR parse a Model class back to a entity/domain class.

public class ModelBuilder
{
    public ProvinceModel Create(Province province)
    {
        Require.NotNull(province);
        Require.NotNullOrEmptyOrWhitespace(province.Name);

        return new ProvinceModel
        {
            Id = province.Id,
            Name = province.Name
        };
    }

    public Province Parse(ProvinceModel model)
    {
        Require.NotNull(model);
        Require.NotNullOrEmptyOrWhitespace(model.Name);

        return new Province
        {
            Id = model.Id,
            Name = model.Name
        };
    }
}

Wondering what that Require stuff is? Those are just some handy methods contained in the Rework Nuget Package (yes, this is a shameless plug).

ModelBuilder In Action:

I usually either inject my model builder in the constructor for the class that needs to use it, or just instantiate it right there in the constructor. The later does make it a concrete dependency rather than an abstraction but sometimes this makes sense IMO.

You could, either create a model builder for each entity-domain relationship you have or just put them all in one. You are reading this blog so I will assume that you are smart and can figure out what you prefer ;).

For completeness, here is how you actually use the thing:

    public ProvinceController(IProvinceService service)
    {
        // Init my service and create my model builder
        _service = service;
        _builder = new ModelBuilder();
    }

   public object Post(ProvinceModel model)
    {
        Province province = _builder.Parse(model);
        _provinceService.Create(province); // My "service" is creating the province in the DB
        return _builder.Create(province);
    }

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2 Simple Steps to Start .NET Development

After recently taking on board a .NET newbie at work, it became apparent that it is not obvious what hardware and software you need to become a .NET dev

2 Simple Steps to Start .NET Development

In this article I will be talking about what you need to start developing for the full .NET Framework.

Disclaimer

While following these steps will just about get you there to develop for .NET Core, you can actually use a much simpler setup if only targeting .NET Core.

For more info, on .NET Core head on over to this article. Have a browse around the site for all sorts of other information too.

Step 1 - Get some hardware

To do .NET development using the full .NET framework you are going to need a windows computer. Ideally something with decent specs and a bit of RAM. You will be spending a lot of time in GUI RAM heavy tools.

My current machine is an Acer Aspire S7 Ultrabook with an Intel Core i7 CPU, 8 Gigs RAM and a 256 SSD. You don't need something this powerful but I'd say an i5 with 8 Gigs of RAM is probably the minimum specs you want to run.

Step 2 - Install some software

You only really need to install one bit of software to start programming in .NET and that is Visual Studio. Visual Studio is an IDE that you will pretty much find yourself living in during most of your development.

At the time of writing, I am using Visual Studio 2015 Enterprise but you will get on just fine with the free Visual Studio Community Edition. You can download Visual Studio from here.

Optional Step 3

Web Development

If you are wanting to also build websites using the popular ASP.NET framework you are also going to need to enable some windows features.

Go into you programs and features settings and enable Internet Information Services (aka IIS) as well as the ASP.NET framework.

Example of what I have enabled:

What  features I have enabled

Database

You will probably find yourself needing a database at some point or another. Generally speaking, you will probably be using Microsoft SQL Server although you could get on just as well with MYSQL or some other relational database technology.

Scott Hanselman has a great blog post on installing MS SQL Server as well as the Management Tools that will make your life a bit easier - both are free.

Comment below if you have any questions.


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New Version of Rework Available

My helper is slowly becoming something useful

New Version of Rework Available

Happy to make a quick announcement that Rework is slowly getting useful!

A new version is out and features some more handy string functions for truncating strings. The library is still very light but does help eradicate some silly boilerplate code

Check it out on Nuget and Github or simple install it with the Nuget Package Manager command Install-Package Rework


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C# 6: Shorten all the things with expression-bodies

Let's see how you can use expression-bodies

C# 6: Shorten all the things with expression-bodies

Let's see how you can use expression-bodies to make your code a lot shorter and more readable.

If you are still writing code like this:

public string FullName 
{ 
    get 
    { 
        return String.Format("{0} {1}", First, Last); 
    } 
}

You really should read my string interpolation post , and write it like this:

public string FullName 
    {
         get 
         { 
               return $"{First} {Last}"; 
         }
     }

The thing is, it gets even better with expression-bodies:

public string FullName => $"{First} {Last}";

That is all.


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C# 6: Get rid of String.Format with Interpolated Strings

So I don't know about anyone else but I am loving Visual Studio 2015 and C# 6.

C# 6: Get rid of String.Format with Interpolated Strings

So I don't know about anyone else but I am loving Visual Studio 2015 and C# 6.

My current favourite feature is the string interpolation. Yes, yes, I know that PHP (and others) have had this for ages but here it is...

Often we would have to do stuff like this:

string first = "Luke"; 

string last = "Warren"; 

string fullName = String.Format("{0} {1}", first, last); 

What a pain!

Now, with string interpolation, we can shorten that last statement to:

string fullName = $"{first} {last}";

Simple but very handy! Just remember the dollar sign before the string. VS will show some nice syntax highlighting to help you out too.

More info: https://msdn.microsoft.com/en-us/library/dn961160.aspx


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Moving Blog from Wordpress to Umbraco

I have finally got around to porting my blog to Umbraco!

Moving Blog from Wordpress to Umbraco

I know I have said in the past that WordPress was probably the way to go for blogging, but in my recent whirlwind romance with Umbraco, I decided to port my blog over.

The main reason was based on the fact that I am much more comfortable in the ASP.NET based Umbraco and hope to make regular feature additions as the blog evolves. Although that is possible with Wordpress, I'd rather stick to my strengths.

In an effort to make my life easier I am also "outsourcing" some other sections of the site, such as the about and contact me sections. This means that the old and rather half-arsed vanilla MVC site that used to occupy this domain has been put down (in a humane and gentle fashion of course).

This site is fully geared towards blogging. The topics will be mainly programming related as usual but you might hear the occasional rambling/rant about the latest goings on in rugby (despite my best effort not to).

All you need to know about me is available via the links in the header of every page. The best place to find out more about me professionally will be via my LinkedIn page. To get hold of me, send me a message via LinkedIn, email or Twitter.

Over the course of the next few weeks I will be moving over my old blog content and killing my wordpress.com site. I will make a post notifying everyone when that takes place although I am sure neither you nor I will miss it.

For those wondering you can find my old blog at lukejkw.wordpress.com

Thanks for reading


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Web UI: Bootstrap is not the only UI Framework!

A Lot of people have been caught up in the Bootstrap hype. It has got to the point where nearly every website/theme was built using Bootstrap.

Web UI: Bootstrap is not the only UI Framework!

A Lot of people have been caught up in the Bootstrap hype. It has got to the point where nearly every website/theme was built using Bootstrap. Now that is all well and good and I use bootstrap myself on many projects but it is not the only UI framework out there. It is scary how many people think that it is.

This blog post serves as an archive of sorts to showcase my favourite web UI frameworks.

Semantic UI

Drawing

Semantic UI is an incredible framework with many feature rich components. The docs are great and the design language makes it easy to theme to your specific needs.

You denote semantic elements with a fluid and "semantic" class structure which make it really easy to learn too.

Materialize

Drawing

Materialize is an awesome little framework based off of Google's Material design.

It is not as feature rich as Semantic or Bootstrap but is a pleasure to use. It is particularly useful for building apps that need to look and feel like native Android apps.

Bootstrap

Drawing

Bootstrap, as previously mentioned, is obviously the most popular out there. If you are working in the web space you need to know how to use bootstrap. The great news is that their docs are great and when you get stuck there are lots of people to help you out on Stack Overflow and other

Have more that should be listed here?

 

Just list it in the comments and I will add it.


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My First Nuget Package: Rework

I am so tired of rewriting the same code over and over and over again

My First Nuget Package: Rework

So I have been wanting to do this for a while but finally got around to creating a reusable C# library.  

The library contains all the sort of helper functions that you tend to re-write, redo or "Rework". It is currently quite light but is fully unit tested and highly reliable. I am using AppVeyor for Continuous Integration and Deployment to Nuget.

I am hoping to do a video at some point on just how easy it is to setup a project in AppVeyor. For more info on the project, it's features and how to use it. Simple head over to Github.

If you like the library and want to add to it, feel free to contact me or put in a pull request.


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