Peter Gfader 's Blog

Resharper VS IntelliJ -> Extract Class

noreply@blogger.com (Peter Gfader) — Tue, 25 Aug 2020 05:26:00 +0000

I do a lot of work with IntelliJ these days and wanted to see if my favourite toolchain (Visual Studio + Resharper) provide a better experience for extracting classes. Here are my learnings.

I have a simple class with too many responsibilities. Easily to see via the "And" in the method name (Nitriq had this as a code rule since the beginning http://www.nitriq.com/).

Lets say I want to split up this class in a "Mapper" and a "XmlGenerator".

How would you do this?
How would you do this in an automated way?

Figure: The smelly class "XmlGenerator" with too many responsibilities

C# and Resharper come first.

Figure: Resharper to the rescue -> "Extract class"

When you click on "Select all suggested members" Resharper tries to find methods that belong together. We would call this Cohesion.
Resharper is not sooo smart to understand responsibilities. It checks who calls who and selects methods that have a call dependency. In our case that would be all methods :/

--> Maybe AI will solve this? 😊

Figure: The human brain decided about cohesion here

Lets go ahead and apply this refactoring.

Resharper does a good job to refactor this. The only ugliness remains is that the call site to the "map" methods use now the dependency in the XmlGenerator and not the Mapper itself.

Figure: Mapper dependency exposed to the outside world

Lets fix that! I give you only hints so that you can try for yourself.

Inline the field.
Inline the property
"Extract field" new Mapper + initialize from constructor
Introduce Parameter in constructor
Rename classes
Happy days

Result:

Figure: Nice code that separates XML generation from mapping of data.

Now lets try this in IntelliJ

We have the same starting point: The tests uses 2 public methods from the XmlGenerator

In IntelliJ the refactoring is called "Extract delegate" and not "Extract class"

IntelliJ inroduces a "Man in the middle smell" which is easy to fix by "Inline" or call site rewrite.

Interesting though that the 2 tools behave so different and have a different name for the refactoring.

IntelliJ seems to be a bit more sophisticated with "Extract Class" refactorings. It seems to provide 3 options as per the documentation https://www.jetbrains.com/help/idea/extract-into-class-refactorings.html

The Resharper documentation can be found here https://www.jetbrains.com/help/resharper/Refactorings__Extract_Class.html

The code to try this yourself is on github https://github.com/peitor/Refactorings-ExtractClass/

5 things I learned about HTTP2 in an afternoon

noreply@blogger.com (Peter Gfader) — Tue, 09 May 2017 08:37:00 +0000

This is a blog post for my future self as a reference for what I learned by googling and reading around the topic of networks and HTTP2.

What problems does HTTP2 try to solve?

In general, the web has a couple of issues today that people try to fix:

Performance -> Slow websites, either on mobile devices, remote areas or bloated web apps themselves
Data usage -> There are still countries where people pay for bytes that go over the air
Power consumption -> The power consumption has direct link to CO2 emission, which data centers try to keep low
Privacy -> Is the web secure? Is your privacy secure?

Lets deep dive into the technical world... (photo from http://gratisography.com/ )

When we look at performance from a technical point of view, there are some issues like:

Latency of the Internet

-> Round Trip Time of bytes is still not great
RTT via ping (ICMP) from Los Angeles to Zurich is about 150ms https://wondernetwork.com/pings/Los+Angeles/Zurich
If you consider the speed of light and the distance from Los Angeles to Zurich, this is not bad. A calculated RTT directly from L.A. to Zurich should be around 30ms

Establishing 1 connection is slow

TCP has a 3-way handshake that is slower than the ICMP ping. https://serverfault.com/a/210850
Establishing lots of those connections to consume a website should be avoided obviously.

The web is bloated

HTML, JS, CSS, Images,
All those things are huge in modern websites but don't need to be
--> It's our job as developers to keep this reasonable!!
HTTP Headers are bloated

Figure: Bloated HTTP Headers, more samples on https://blog.fefe.de/?ts=aa031bbb

What problems of the above does HTTP2 try to solve?

The 3 problems above are addressed by HTTP2, but HTTP2 introduces new problems. More to that later...

HTTP 1.1 solved 2 issues

1. Feature: Connection Keep-Alive

Figure: HTTP Connection Keep-Alive from https://en.wikipedia.org/wiki/HTTP_persistent_connection

Solves the problem of lots of little connections that are slow to establish.

--> This is used a lot around the world and improved performance a lot.

2. HTTP1.1 Feature: HTTP Pipelining

Figure; HTTP1.1 Pipelining Visualization, from https://en.wikipedia.org/wiki/HTTP_pipelining

Solves the latency problem, so that a client can request many resources in 1 batch of requests.

The downside of HTTP1.1 Pipelining

The server needs to respond in the same order that the requests came in. This means the server needs to have some sort of state to manage that. This increases complexity on the server side and allows potential DoS attacks.
A DoS attack could be launched by sending 100 requests to a server and then idling on the client, the server has no chance to detect if this 100 requests are legit or not
Head of line Blocking: A potential slow first response blocks all subsequent responses

Because these issues, HTTP Pipelining failed to gain adoption.

Now comes HTTP2 onto the field with SPDY as its predecessor.

First, what is HTTP2?

The main focus of HTTP2 was to improve end-user perceived performance, the 3 technical performance points above.

HTTP2 is not a ground up rewrite of the HTTP protocol.
It includes the following features:

is binary, instead of textual
is fully multiplexed, instead of ordered and blocking

can, therefore, use 1 connection for parallelism

uses header compression to reduce overhead
allows servers to “push” responses proactively into client caches

All the details are nicely explained in the very readable specification on https://http2.github.io/. See the references for more details.

What new problems are there with HTTP2?

Server side complexity

Header compression and Connection State Handling are hard

This causes complex website configurations
Buggy Webserver (and remember they have a huge attack surface)
More CPU consumption and CO2 emissions

1 connection as single point of failure

With HTTP1 you can lose some connections and the site still loads ok-ish, depending from what you loose
With HTTP2 if you lose that connection, the whole thing is gone

The politics around the specification hindered innovation.

Sadly HTTP2 is a missed opportunity to fix more of the issues mentioned at the beginning

What did you learn about HTTP2 recently?
Do you care about HTTP2? Something you were waiting for?

References:

https://http2.github.io/
https://blog.fefe.de/?ts=aa031bbb
http://queue.acm.org/detail.cfm?id=2716278

https://varvy.com/performance/tcp-connection-time.html

http://royal.pingdom.com/2007/06/01/theoretical-vs-real-world-speed-limit-of-ping/
http://jkle.in/http2
https://hpbn.co/http2/

Cage Fight: Electronic VS Physical Boards

noreply@blogger.com (Peter Gfader) — Mon, 01 May 2017 12:27:00 +0000

Every time I join a team that is physically co-located I propose to use a big-ass-board to track work and visualizes stuff. Usually, there are a couple of questions around these boards and I point people to different blog posts which I collected on my Brain Noise Blog http://gfader.tumblr.com/tagged/taskBoard.

This time I got 5 great reasons for using an electronic task board, that I want to answer here.

Cage fight!!!
Physical Boards VS Electronic Boards

Figure: Physical VS Electronic Boards - Thanks, Google Image Search

Peter, I think these are 5 advantages of an electronic task board. What do you think?

Single Source of Truth
No media disruption between code and board.
Some people like to relate tests or code pieces to ticket numbers
The electronic board is always available.
At home office or in another meeting room
Change and History Feature
Lots of space to describe a story or bug in all details

Before we dig into these great points, let me clarify 6 observations I made in the past.

#1
Software development work is not visible. That’s the reason I prefer “Information Radiators” instead of electronic boards that act like “Information Fridges”.

Information Radiators (Visual Management) allow everyone to quickly see what’s going on:

What’s blocking?
Is everything healthy?
Use a Build Monitor and a System Monitor
Are we on track?
Show Scope and updated Budget from our accounting system on a 3rd monitor

Figure: Jira is an Information Fridge (Tip from the Kanban in Action book)

Information fridges hide work. You need to open the fridge, in order to see inside it, dig around it and hopefully find what you were looking for.

Information Radiators are a public display of information in a highly-visible location so that anyone can see and comment on it. This can be hand-written, printed or electronic and could be dashboards, charts, metrics or task boards. Also called Big Visible Charts and used within Informative Workspaces. This is opposite to Information Fridges where information is hidden and cannot be seen within specific access.
From http://pragmaticscrum.info/agile-glossary/

#2
In my experience, physical boards involve more senses and make the people working with the tool more committed and engaged in their work.

#3
A physical board invites other people (non-Jira or TFS users) to join the conversation. They might ask questions and you can collaborate on work items on the board immediately.
This is a great opportunity to work together with the end-user or management people. These people feel usually detached. Get them on board!

#4
Last but not least a physical board is easy to manipulate. Everyone can use am Index card, Post-It, and a pen and collaborate on that board. With electronic tools, there are hundreds of issues like keyboard layouts (German vs English), shortcuts, URLs for Boards, Drag and Drop, Mouse Speed, Screen size and a lot more that hinder you from working together.

#5
Your workflow changes over time because you adapt your practices and your way of working together. As your workflow changes, you need to adapt your board that reflects this.
Electronic tools and boards are harder to change and usually you need a TFS or Jira Master to do so.
Physical Boards are easy to change and the whole team is involved in it.

Figure: Are you still visualizing "Todo, InProgress, Done"?
Board example from https://mysoftwarequality.wordpress.com/2013/09/10/how-i-stopped-logging-bugs-and-started-living-happy/

#6
The Physical Board is for the team, and the team should set it up, work on and change it. By letting the team set it up they make it theirs. They are more committed because it's theirs and more proud of it.

Thanks for reading this far...

Now back to the 5 valid reasons for an electronic tool and some input to stretch your mind.

1. Single Source of Truth
What if the single source of truth is your codebase?
What if you document your production code with executable specifications?
What if you deliver working software so quickly that there is no need to write every bits and piece down? Instead, you collaborate over prototypes, mockups, working software...

2. No media disruption between code and board.

Some people like to relate tests or code pieces to ticket numbers

What if your codebase lives for 10 years, but your TFS Installation or Jira gets replaced with a better tool just around the corner?
How could you document the ticket details in your codebase?

3.The electronic board is always available, at home office or in another meeting room

What if the board location is your meeting room?
What if you take IndexCards or PostIts home? Remember to get them done and bring them back ;-)

4. Change and History Feature

5. Lots of space to describe a story or bug in all details
What if instead of managing work your get more work done, so you don't need the change and history feature? What if you increase your delivery speed?
How can you increase your delivery speed?
How could you decrease the feedback loop to the end users?
How can you measure faster the impact on your business?
How can you try ideas as you think of them?

I think it all comes down to:

Shorten the feedback loops to the end user
&
Break down the silos between the development team and end user

What do you do to increase collaboration with the end user?

References for further reading:

Kanban in Action book
https://www.manning.com/books/kanban-in-action
Kanban boards step by step
https://www.slideshare.net/GiulioRoggero/how-a-kanban-board-works

What bad developers say and what to do about it

noreply@blogger.com (Peter Gfader) — Wed, 21 Oct 2015 10:18:00 +0000

I am still alive and I am still blogging, just not here so much ;-)
I blog more on my company Zühlke blog, on my technology tumblr blog Gfader brain noise, and another tumblr about Stop doing Agile - Business Agility - my adventures with organisations that want to improve.

So this is a little traffic generating, SEO link exchanging, cross post:

I talk to a lot of people (if the day is long enough) and so I get them to ask interesting questions like:

“What have you learned recently?”
or
“What is your top 1 goal for 2020?”

These questions and more leads us to interesting conversations about personal development and personal goals that a person has. Being a Scrum.org Trainer, I like to ask people questions especially related to software development so I ask them:

“How well are your teams doing?”

“How do you know?”

“What do you think is the content of the ‘Professional Scrum Developer’ class?“.

Especially to the last question I get this face

Figure: “No clue” from http://xenaandjonesgiflibrary.tumblr.com/post/42761898144

Read the full blog post on our Zühlke Blog: 5 things bad developers say and what to do about it.

And by the way…

Here are the follow ups:

How do you apply changes to your codebase? When should we merge the JoeBranch?

noreply@blogger.com (Peter Gfader) — Thu, 16 Apr 2015 09:03:00 +0000

At our yearly 1 week Zühlke web camp a couple of us took the opportunity to share experiences with branching and release techniques.

TL DR;

Focus on Continuous Integration
Every change that you have locally is a branch (a code version that is different than main)
Every kind of branching delays Continuous Integration
Only a healthy code base with a “green” Build + Automated Tests let you sleep like a baby at night.

Things to think about:

How can you slice your work so that you can commit every 1 hour? (Incremental change)
How can you get faster feedback from your Build Server?
How can you do code reviews and keep quality high?
Why do you need the 1 person code gate keeper that signs off all code?

This is what we found:

2 overall goals

Get features to the user as fast as possible.
Ensure our work is good (quality aka the “the thing right”) and good for the user (“the right thing”)

What is Continuous Integration?

“Continuous integration (CI) is the practice, in software engineering, of merging all developer working copies with a shared mainline several times a day.”
From http://en.wikipedia.org/wiki/Continuous_integration

If you have shelve-sets (TFS), stashes (git), long lived (>1day) feature branches you are not doing Continuous Integration. You are delaying the Integration work which is waste and a potential risk. Even if you have a sophisticated build system that builds all branches and each distinct tree in a revision list, you still don’t know if all integrates well.

Why Continuous Integration?

Are all our changes healthy? Is our main line healthy? Could we release the code on main line just now to Production? Why not?
We want get fast feedback about our code base.

In an agile context we are very keen on feedback and implement lots of feedback loops. One of those feedback loops is the Build Server feedback as illustrated on Use Continuous Delivery to build the right thing.

Figure: Feedback loops

What techniques for branching exist?

Note: Every change that you make on your local machine is in fact already a branch. That change needs to be merged (commit&push, check-in in TFS terms) back to main

Release Branch: A code version that is released to an environment has its own branch.
Do you create this branch on release time? Or later if you need a bug fix for that environment?
I prefer the latter since you create unneeded complexity in your code base (waste).
“Spike” Branch: A code version that you potentially throw away or just want to share with another smaller group of developers.
Feature Branch: A code version where your work on a feature is isolated from others.

Some more are documented here https://www.atlassian.com/git/tutorials/comparing-workflows/gitflow-workflow

What does it depend upon which technique you use?

Team size
Available Tooling + Team Skill level
Release procedure
Software Architecture (Web, SmartClient, MobileApp)

What are reasons that you don’t have 1 main branch?

Other interesting branching and releasing models

Branch by Abstraction
http://paulhammant.com/blog/branch_by_abstraction.html

GitFlow Workflow
https://www.atlassian.com/git/tutorials/comparing-workflows/gitflow-workflow

GitHub Flow
“anything in the master branch is always deployable”
https://guides.github.com/introduction/flow/index.html

Other interesting techniques

„Feature Toggling” http://martinfowler.com/bliki/FeatureToggle.html
“Canary Releases” http://martinfowler.com/bliki/CanaryRelease.html
"Dark Launching" https://www.facebook.com/note.php?note_id=96390263919

Feature Toggles

In my experience “Feature Toggles” can lead to similar problems as lots of branches:

What is on and off on this environment / server?
Does Feature X work in conjunction with Y?

But some advantages I found:

Testing gets easier

Either something is stable (no toggle) or not (toggle)

No build needed for special patches
Feature not working OK in Production? Turn it off

How many FeatureToggles do you have in your system?
Do you remove them consistently once they are “done”?

Are you a Professional?

noreply@blogger.com (Peter Gfader) — Mon, 23 Feb 2015 15:46:00 +0000

Figure: What does it mean to be a Professional Scrum Developer?

My geek friends from Scrum.org were so bored at the last get-together that they have produced a nice video: ”What does it mean to be a Professional Scrum Developer?” embedded below for your quick viewing pleasure.

“I am a Professional and I am part of a team. A team that is cross-functional with all necessary skills to deliver software frequently.
We are programmers, testers, DBAs, designers, architects, business analysts, requirements engineers and are all part of the same team.
The development team.”

Are you a Professional ?

The other reason why I blog about this video is that I published another post on my company blog, and I wanted to cross reference that blog post from here to there.

Check out my company Zühlke blog about: 5 things bad developers say and what to do about it
http://blog.zuehlke.com/en/5-things-bad-developers-say-and-what-to-do-about-it/

The future web development: where are we heading?

noreply@blogger.com (Peter Gfader) — Mon, 13 Jan 2014 20:52:00 +0000

Figure: The web as we know it

The web is easy I thought 15 years ago, 15 years later I still haven’t mastered it. Here are some thoughts on the future of the web.

In the picture above you see on how we did things in the past. We deliver HTML over HTTP to a client (the web browser), and the user interacts with the browser and potentially sends more GET requests or POSTs some data to the server. We smart developers delivered additional CSS to make the page look pretty and additionally some JavaScript to smarten up the client.
This is all nice and working great but we have 2 major problems in the web world:

I identified all evil in web development: slow networks, F5 refresh, back button and the user.
— Peter Gfader (@peitor) January 11, 2014

Problem #1: "Slow" networks

Because the internet/networks are slow and every page request to the server is slow, we started to do more and more work in the browser itself via JavaScript:

We validate input before we send it to the server
We load only partially the page (XMLHttpRequest)
We show the user something that is not posted or loaded from the server yet

All these actions give the user a nice experience and a more responsive user interface. I blogged about 8 Web Performance Tips in the past, but here we don’t talk about those.

The problem with all those actions is that we are manipulating stuff in the client. That “stuff” was generated on the server and now we manipulate it again on the client.

Figure: A GET request to the server causes the server to render a template (view) + data (model) to HTML

An example would be handy right now

Example: You render HTML with Razor or your preferred server side language and use the "Id" of the input field to find it later via jQuery or your preferred client side DOM manipulation framework.
I am not even sure what the example below tries to do, but it shows the main problem: Manipulating (Rendering) HTML on the server and then manipulate HTML on the client again.

Server side code (view that renders data)

using (@Html.BeginForm(new { id= @addName}))
{
    @Html.TextBoxFor(model => model.EndValue, new { id = @newName, size = "5", style = "margin-right: 10px" })
    @Html.HiddenFor(model => model.ModuleTypeId, new { @Value = @ViewBag.ModuleId }
    @Html.DropDownListFor(model => model.DPId, @dpList, "Choose an Option...", new { @class = "select" })
}

Client side code (jQuery to manipulate the view)

   $('#@saveName').click( function (event) {
        event.preventDefault();
        $.ajax({
            url: '@Url.Action("SaveADP", "Dispense")',
            type: 'POST',
            data: $('#@addName').serialize(),
            success: function (data) {
                $('#@divId').html(data);
            }
        })
    })

Taken from this Stackoverflow question about Posting MVC Razor form from ajax

This is a kind of violation of the DRY principle and it is actually hard and messy, since we manipulate the DOM on the client and the server.

Problem #2: "State" (F5 or back button problem)

We have state information like:

Is the user logged in
Navigation
Previous Page
Search Terms
Filters
Shopping Cart
…

And need to save that somewhere. Candidates for that are:

URL
- Example. http://yourserver/folder/(session ID here)/default.aspx
  Needless to say that I don’t like this. As a web developer you should really care about nice URLs!!!
HTTP header: Cookie as example
- Part of every request, this is a little token that gets sent to your server
Page
- Via (hidden) fields, we render state information into the returning page. Viewstate is a bad example for this.

On the Server we store that state:

Session
- Memory on the server identified by a cookie
  That memory can be on a separate server State Server, but let’s leave that out of the discussion for now
Persistent store (Database)
- Why not store the ShoppingCart in the database instead of fluent memory that could be lost by a crash of the server or client (wherever that memory was sitting)

All these stores for state have their place and many blogs have been written about advantages and disadvantages of those.
Storing the state on the server makes the server state-full. That means if your server goes down everything is lost, unless you persist is somewhere. This also means that with every request that comes in the server must determine the state of the current request and deliver output depending from that state. This makes the server slow and difficult to maintain.

What should we do then?

What about moving the state of your app to the client?
Storing state in the client is the primary purpose of a Single-Page-Application or a SPA. In this case the client web browser loads the page and the page has enough “brain” to know it’s state and to interact with the server. This brain is typically JavaScript and objects living in the JavaScript memory space.
Many jokes happened around the term “SPA” so I leave those up to you to google for them.

Figure: Brains on the Server and the Client

But Peter… What about Silverlight and Flash?

Silverlight and Flash are a hack!
And they are dying anyway.
But you are right the stored state in the client, and solved some of these problems. But let’s forget them and let’s look in the future.

Where are we going from here?

I think the answer is clearly state-full client or in other words: Single Page Application.
We want to move the state from the server to the client. Make the client smarter and the server dumber. Allow the server only to send data via a nice and clean REST interface.
Think about the webserver as a man-in-the-middle between the database and the client.
Imagine the server as a stupid web service endpoint and the client as a consumer and sender of data from those services and potentially aggregate data from different services.

Figure: A smart Client (Browser with page) that consumes data + templates from different servers (CORS needed)

To build this "smart" page we need JavaScript.
I would recommend you to learn the basics: HTTP, HTML, CSS, JavaScript and then use a framework like AngularJS or emberJS, because lots of problems have been solved by those frameworks and many good things are in those frameworks that help you to get started quickly.
Additionally learn and use TypeScript or CoffeeScript to give you a head start with JavaScript. If you have more time learn SQL, DDD, Regex, C#, Scrum a little Kanban. Oh, and make sure to improve your communication skills.

This Single Page Application stores the state on the client side in either the HTML DOM (old school and similar to the way you were manipulating the DOM via jQuery) or in memory via JS objects (the preferred way). All major client-side databinding frameworks that I know use the latter these days: AngularJS and Knockout. Are there more? Sorry I cant keep up with that xxxJS release water hose.

Why would you invest your time in creating a Single-Page-Application?

Faster and more fluid UI
- The server logic is thinner, the server has less responsibilities
- Your applications markup is loaded from the server just one and all additional calls are just data
  More fluid user experience with a single page architecture
- Mobile application is just a different view that you provide to the client (sounds easy)
High Scalability
- GET request turn out to be highly cacheable (most of the times)
- You use HTTP as its intended to be used
- The server is stateless and you could have 1000s of servers that act the same as 1 server
Easier server side development

The client gets more responsibility and state and the server side development gets easier DoubleWin

Declarative data binding directly in HTML

Why would you not create a Single Page Application?

Your team has huge skills in classic server side web development
- ATM you get less tool support to develop client side. I would argue this is a good thing, since you need to focus more on testing and thinking about how you structure your application
You want to avoid Javascript like the pest
Your team doesn’t follow all the latest and greatest script kiddies
You don’t care about HTTP, HTML, CSS and just want to get your job done ASAP
You don’t mind ugly URLs and don’t care about the browser history as long as your app works
Your application startup time is critical (no progress bars allowed)
The view rendered by the server is never touched by the client

from
Why not a Single Page Application (SPA)?
http://gfader.tumblr.com/post/70800309829/why-not-a-single-page-application-spa

Want to read more about Web Development?

Where do you think the web is heading to?

The TicTacToe Kata in C# – A TestDriven approach

noreply@blogger.com (Peter Gfader) — Mon, 08 Jul 2013 19:48:00 +0000

This is for my future self to see how I look like on camera while coding ;-)
And I am doing another experiment to see if people are interested in this kind of stuff.

I turned on Camtasia and recorded myself during my weekly practice sessions. Published on youtube and now I wait and see what the reactions are.
Tools used: mstest, VisualStudio 2012, Resharper and Notepad.

Figure: Is the font big enough? Is my picture small enough? Is my voice annoying enough? Let me know!

The TicTacToe Kata

A simulation of the TicTacToe game, where 2 players can play Tic-Tac-Toe against each other.

Goal of a Kata session (straight from Kata martial arts):

preserve and transmit proven techniques and to
practice

For me its not so much about proven techniques, but more about practicing and exploring new languages, frameworks and tools.

Video 1/4 (7 minutes)

Starting the Kata with a test written in Notepad and then slowly building the 1st test by example.
I use the inconclusive Assert.Inconclusive() tests as my TODO list.

Video 2/4 (21 minutes)

In this video I start with 1 passing test and 2 inconclusive tests.
Tests drive my implementation and slowly I build up the API of the game.
Making my tests more specific helps me maintain them. And I discover that previous tests have value. Wow!
I have 3 failing tests and 4 passing tests at the end, just got stuck With with extracting the “GameBoard” class.

Video 3/4 (15 minutes)

In this video I fix the bug (1 red test) with which I got stuck with the previously. I continue to drive out the implementation of the “GameBoard” and implement more and more game rules.

Video 4/4 (12 minutes)

In this video I have the Game logic working to identify winners in a row.
Time to finish up all the game rules!

Now its up to you:

What did you like in the video series?
What didn’t you like?
What could I improve?

How do you continuously improve yourself? An interview with SSW TV

noreply@blogger.com (Peter Gfader) — Sun, 09 Jun 2013 15:11:00 +0000

~~This went viral on YouTube the other day, aka~~ my mum clicked it 100 times.

Figure: Me and Adam Stephensen rambling around

I had a conversation / interview with my good friend Adam Stephenson about Clean Code, Quality, Releasing Software more often, Continuous Delivery and all things that make developers happy.
Check it out!

The top one is an image, the below is the video.

http://tv.ssw.com/3256/clean-code-testing-continuous-improvement-with-peter-gfader

The Agile Manifesto 3.0

noreply@blogger.com (Peter Gfader) — Fri, 10 May 2013 11:28:00 +0000

This is the 1st principle of the Agile Manifesto from the year 2001 that you can find on http://agilemanifesto.org/

Figure: First principle of the Agile Manifesto from 2001

----------------------------------

Although I couldn’t agree with this more, I think in the last years this changed a bit.
Especially with the introduction of the “Lean Startup” movement

Figure: First principle of the Agile Manifesto 2.0

Lets call this the “Agile Manifesto 2.0”

----------------------------------

After talking to Jurgen Appelo and reading his blog post about “The purpose of a business is NOT customer values” I came up with the “1st principle of the Agile Manifesto 3.0”.

Figure: First principle of the Agile Manifesto 3.0

Jurgen calls BS on “delight the customer” and is keen on satisfying everyone involved: stockholders, employees, suppliers, customers, community, the environment,. ..
It might be hard to satisfy everyone with valuable software, but having that as goal is great.

Note: If I skip the “delight the customer” step I couldn’t come up with 3.0
and I really wanted to align this with the “Management 3.0” naming of Jurgen. --> Which I like!

BTW: Another way to look at it might be:

In Agile 1.0 we build something and learn if the customer likes it or not as quickly as possible
In Agile 2.0 we try to learn about the customer and measure what delights him in order to know what to build
In Agile 3.0 we look at the bigger picture of all parties involved

What do you think? Brain fart? Helpful to think about your business?

How to increase the Code Coverage in 2 easy steps

noreply@blogger.com (Peter Gfader) — Wed, 20 Feb 2013 17:33:00 +0000

As a developer you come to the point in time where a manager asks you to have at least 80% Code Coverage in your code.

Photo Credit: Sam Foster

All managers love to see numbers, especially big increasing numbers.
I love big numbers too!

The nasty ones of you might ask a question back:

“Why do you want those numbers?” or
“What do you need those numbers for?” or
“Who are you going to show them?”

But let’s not do a “Root Cause Analysis” here and just solve the symptom.

Lets look at this project and the Code Coverage for it.

Figure: Before: 74.83 % Code Coverage

Here is how you can increase your code coverage in 2 easy steps.

Copy the following into your production code

// Call this method something important. 
// Use words like: Manager, Proxy, Controller, Command, Dispatcher, Broker, Container …
public bool IsMessageProxyControllerManager()
{
    //Repeat more often to increase Code Coverage
    CreateNewImplementation(); 
    CreateNewImplementation();
    CreateNewImplementation();
    CreateNewImplementation(); 
    CreateNewImplementation();
    CreateNewImplementation();
    CreateNewImplementation();
    CreateNewImplementation();
    CreateNewImplementation();
    CreateNewImplementation();
    CreateNewImplementation();
    CreateNewImplementation();
    CreateNewImplementation();
    CreateNewImplementation(); 
    CreateNewImplementation();
    CreateNewImplementation();
    CreateNewImplementation(); 
    CreateNewImplementation();
    return true;
}

// Rename this to something important. 
// Mix 2 words from: Invoke, Caller, Fetch, Request, Factory, Synchronizer, Shepherd, Coordinator 
// 
// If you cant come up with something use https://github.com/ab9/classnamer 
public void CreateNewImplementation()
{
    
}

Copy the following in your test code

[TestMethod]
public void GivenANewInstance_MessageProxyControllerManager_ExpectAPositiveAnswer()
{
    var c = new ClassWhereYouCopiedThe2Methods();  // Change this
    var result = c.IsMessageProxyControllerManager();
    Assert.IsTrue(result);
}

Run the Code Coverage Tester again, and Voila!

Figure: After: Increased Code Coverage from 74% to 79% Code Coverage

Think about what Code Coverage really tells you

Does it really measure code lines tested?
Or does it measure code lines executed?
What does that number tell you?
Is it of value to you? To a manager?
Is 80% Code Coverage a good goal?

Now… what are you going to tell your manager?

Combine Scrum and Continuous Delivery to drive Innovation

noreply@blogger.com (Peter Gfader) — Fri, 08 Feb 2013 12:26:00 +0000

After publishing the paper on scrum.org here, I wrote a german version for the dotnetpro magazine of January 2013.

Check it out!
And make sure to buy the magazine!

An excerpt from the magazine [GERMAN]

Zügige Rückmeldungen von Nutzern helfen, neue Merkmale schnell umzusetzen. Damit Entwickler und Endanwender
zusammenfinden, lassen sich Scrum und Continuous Delivery gut kombinieren.

Zu den wichtigsten Konzepten agiler Softwareentwicklung gehört schnelles Feedback, am besten in Form kleinerer und größerer Feedbackzyklen, je nach Produktionsstadium; Abbildung 1 zeigt die verschiedenen Zyklen und ihr zusammenwirken in einem Überblick. Dieses Feedbackkonzept hat sich in den vergangenen Jahren zur Idee von „Continuous Delivery“ entwickelt, also zur „kontinuierlichen Auslieferung“ des jeweiligen Systems, das im Lauf dieser Zyklen permanent neu übersetzt wird. Dies soll es ermöglichen, das Produkt und seine Veränderungen so einfach und
so schnell wie möglich dem Endnutzer, also dem Kunden, zur Verfügung zu stellen. Damit dies möglich ist, muss das Produkt während der Entwicklung jederzeit in einem Zustand sein, der erlaubt, es zu veröffentlichen [1].

Full Article
Gemeinsam stark
http://www.zuehlke.com/fileadmin/pdf/fachartikel/254_dnp_gemeinsam_stark_pgf.pdf

Innovation through Scrum + Continuous Delivery [VIDEO]

noreply@blogger.com (Peter Gfader) — Thu, 13 Dec 2012 18:53:00 +0000

Update 2014-11-05: Fixed the video link since the Scrum.org Video Channel moved.

I almost forgot to publish this recording here…

Figure: My talk on youtube https://www.youtube.com/watch?v=TMyhhuQPEow

How often do you release your product to your end users?
How often do your end users see and use your product?
Do you release in sync with your Sprint length, after the Sprint Review?
Is the Sprint Review meeting the only valid release point?
When do you plan your releases?

See how the cadence of Scrum and Continuous Integration can help you build the right thing, and when implemented properly, release it on time to ultimately deliver superior value to your customers.

Efficiency and Effectiveness and some thoughts about it

noreply@blogger.com (Peter Gfader) — Sun, 02 Dec 2012 11:32:00 +0000

What caught my attention recently: Efficiency vs. Effectiveness

Figure: Early enough to learn to code efficiently. flickr

I heard a talk from a fellow Scrum trainer that led me dig more into these 2 terms: "efficiency" and "effectiveness".
The way I remember them is

“Being effective is about doing the right things, while being efficient is about doing the things right.”

Ask yourself:

Which one is more important? “efficiency" or "effectiveness”
Which one should you focus on?
Which one could be improved in your project?
How do you measure those two?

Figure: Are you doing something efficiently? Should you focus more on effectiveness?
Picture taken from Henrik Kniebergs slide deck: "The Thinking Tool Called Agile” –> Check it out

Some links to dig into that topic

The difference between "efficiency" and "effectiveness".
http://www.dailyblogtips.com/effective-vs-efficient-difference/

Outsourcing and efficiency/effectiveness
http://gfader.tumblr.com/post/32512202396/do-not-outsource-your-software-development

The 3 Pillars of Personal Effectiveness
http://gfader.tumblr.com/post/29116159986/minibook-the-3-pillars-of-personal-effectiveness

Is productivity a combination of efficiency and effectiveness?

Use Scrum + Continuous Delivery to build the right thing

noreply@blogger.com (Peter Gfader) — Thu, 25 Oct 2012 12:48:00 +0000

Figure: How and how often do you get feedback? flickr
The two topics “Scrum” and “Continuous Delivery” kept me very excited in the last years, which resulted in two presentations and a whitepaper for scrum.org.
Answer the following questions:

How often do your endusers use your product?
How often do you release your product to your end users?
Do you release in sync with your Sprint length, after the Sprint Review?
Is the Sprint Review meeting the only valid release point?

In the whitepaper (link at the bottom) I talk about how the cadence of Scrum and Continuous Delivery can help you build the right thing, and when implemented properly, release it on time to ultimately deliver superior value to your customers. Wow… That is a lot!

Two pictures out of the whitepaper, to make it a little bit more tasty to read

Figure: Feedback loops in agile software development

Figure: Continuous Delivery added to the Scrum cycle
(In German since I write a similar article for a German article)

If you haven’t read it yet, give it read and let me know what you think!

Use Scrum + Continuous Delivery to build the right thing

Lean, Agile, Scrum Zurich conference slides

noreply@blogger.com (Peter Gfader) — Mon, 17 Sep 2012 19:43:00 +0000

The Lean Agile Scrum conference 2012 is history.
This conference was a blast. All the discussions after and between the talks were superb, and getting to meet new people is always AWESOME (until a shark and a gorilla high-five each other in front of a en explosion –> Thanks Joe)

2 quick impressions from the conference

Figure: The pictures are so blurry because I was so excited to give a session later

My little contribution to this conference aka slides on SlideShare

Innovation durch Scrum und Continuous Delivery from Peter Gfader IN GERMAN

PS: As per my other blog entry about Conferences to attend this year I gave the conference only 2 happy rainbows.
Not sure why. This conference deserves at least 4 rainbows!

What was your impression?
What were the best bits of the conference?

Ease your Visual Studio development with a SQL Server alias

noreply@blogger.com (Peter Gfader) — Thu, 16 Aug 2012 19:07:00 +0000

A quick little tip on how to manage connection strings in your applications with a SQL Alias that you can create with “SQL Server Configuration Manager”

If you have a specific connection string in your application.config like

<connectionStrings>
  <add 
    name="NorthwindConnectionString" 
    connectionString="Data Source=MyLittleLaptop\SQLExpress; 
     Initial Catalog=Northwind; Persist Security Info=True;
     User ID=userName;Password=password"
    providerName="System.Data.SqlClient"
  />
</connectionStrings>

In order to avoid

#1 merge conflicts on every check in

#2 to remember to exclude the app.config (or web.config) on every check in

Figure: Exclude the app.config because I needed to change the DB connectionstring to “.\SQLExpress”

#3 getting beaten by other developers

Create a SQL Alias with SQL Server Configuration Manager

Open SQL Configuration Manager
Go to “SQL Native Client 10.0 Configuration (32bit)”
My client is a 32bit process
Create a new alias
In my case called: “.\USTER” since that is DB name that we agreed on

Figure: “.\USTER” points to “.\MSSQL” via Named Pipes
Ready to rock!

Make sure to enable “Named Pipes” for that SQL instance

Happy days in your development team!

BTW: If you deploy your application to different environments you can and should change server names via “XML transforms” or “XML Parametrizations”

First steps with Machine.Specifications (BDD framework)

noreply@blogger.com (Peter Gfader) — Mon, 09 Jul 2012 18:13:00 +0000

Figure: How do you specify this machine?

As you may have read in my previous blog post: On the road to BDD… Or… to see the light, I am dabbling more and more into the ATDD / BDD world.

These are my impressions from Machine.Specifications.
BTW: Gread video from JP Boodhoo about Getting up and running with MSpec

1st impression:

It takes a little while to get used to the funky () => syntax,
but now I love the readability of my tests...

Sample tests

    public class When_Adding_a_String_With_2_Numbers
    {
        Establish c = () =>
                calculator = new Calculator();

        Because b = () =>
                result = calculator.Add("1,2");

        It Should_return_the_sum_of_the_string = () =>
                result.ShouldEqual(5);


        static int result;
        static Calculator calculator;
    }



    public class When_Adding_an_Empty_String 
    {
        Establish c = () =>
                calculator = new Calculator();
        
        Because b = () =>
                            result = calculator.Add("");

        It Should_return_0 = () =>
                            result.ShouldEqual(0);

        static int result;
        static Calculator calculator;
    }

I love this test output:

When Adding AString With 2 Numbers
» Should return the sum of the string

When Adding An Empty String
» Should return the sum of the string

Contexts: 2, Specifications: 2, Time: 0.21 seconds

Figure: Test output of the mSpec runner - Underscores get replaced with spaces in the test output.
BTW: I heard the new runner for xunit in VS2012 does that as well.

My 2cents:

I need to figure how to structure my tests better to get the nice distinction between Scenarios and Features
I would say that the MSpec Framework is more designated for developers that want to discuss and show the test output to the business people.
Working on the tests itself (code) together with the business is not an good option with MSpec
It feels weird at the beginning when there is a class that is your test. Instead of a method that is your test
Duplication needs to be taken care of by refactoring out into base classes or Factory methods

What is your impression of mSpec?

Code52 Show and Tell: My pet project CopyCat - Lessons learned

noreply@blogger.com (Peter Gfader) — Sun, 17 Jun 2012 20:52:00 +0000

Figure: CopyCat – A big fat cat walking and waltzing the internetz

I am a pretty normal geek. At least I think I am normal and a geek. I see geeks as people (yes really) that want to play with things, discover new things and build things. When geeks play with things they discover new things quite often.
(Similar story heard and “adapted” from Scott Hanselman)
After I ‘ve discovered something I want to scream it out to someone:

“Look at this dude!! Isn’t that awesome???”

A normal reaction that you get from a non-geek:

“Wow… Is this showing the weather in form of colors that you could just get by watching out the window?”

This is the pattern for the reaction that you normally get
“Wow… Is this <something> that does <somethingUselessAtBeginning> that you could just get by doing <somethingElse>?”

As you may realized I am such a geek and so I play with different things in my spare time, and build little silly things.
Deep inside me there is still this hope to build something random awesome and get rich and buy me a mountain or an island.
2 other reasons for doing so are:

#2 I want to play with the new shiny toys that I can’t play with during my 9-5 job.

#3 It is so easy to develop something new these days. We have so many Lego blocks available that you can just plug together.

For those 3 reasons I created CopyCat.

I have a couple of “awesome” (or maybe silly?) ideas in my "List with Ideas to rule the world" and this February I got around to finally build “CopyCat”

What is CopyCat?
CopyCat solves 2 problems:

You create some great content and want to make sure that no one is stealing it.
CopyCat looks around the web for your content and tells you if someone copied it.
You create some content with the help of Google and want to make sure it is still distinctive enough from other content.
So that no one can say that you copied from others, as it happened to Defense Minister Guttenberg

--------------------------

With CopyCat I really wanted to get the minimum usable product online ASAP. A so called MVP

“If your beta product doesn't embarrass you, you are not Startup”
Eric Ries (I think said this somewhere)

After playing around with AppHarbor and Bitbucket (git) I figured that putting an "idea" online is easy.

The Lego Pieces that I used:
From “File New MVC App” until Going Live, there are only a couple of steps. See AppHarbor Support: Deploying your first application using Git

These are the Lego pieces I used

ASP.NET MVC
jQuery
Elmah
Cassette (Uglify and Bundle CSS and JS)
BitBucket: Source control Git
Msys git (No Github Windows client yet)
Appharbor: Hosting (with Automated Continuous Deployment)
NUnit: Test framework
MongoDB: NoSQL repository
C# MongoDB driver
Nuget: Package Management to get all Lego pieces
TDD: No production code without failing test (almost).
I am not test driving my MVC controllers, because I found that too cumbersome
trello: Taskboard for keeping track of features and work

You might ask: Why is this code not open source on Github or somewhere?
Mainly because I couldn’t figure on how to exclude my API keys from other curious readers.

Lessons learned

Code maintenance

Maintaining tests takes time and is definitely worth the effort
Treat tests the same as production code

Figure: Solution layout of CopyCat

Figure: Test layout of EndToEnd Tests, Integration Tests and Unit Tests. Makes your dev life easier

Tests

Limited Web APIs are a #pain with Integration tests

I am using GoogleSearch API and that is limited to a certain amount of calls per day. Running tests that use that API causes you to reach the API limit pretty quick and you get failing tests for API limit reason.
Or even worse you have to pay some money, because you used the API too much.
My solution: Have a façade for your External API, and have only some Integration tests that work with the external API
TDD doesn't help you write an algorithm
I tried and I failed.
I am just much better by thinking on paper. Uncle Bob has an interesting approach called: The Transformation Priority Premise
This is my biggest learning point over the last months… Watching the Bowling Kata

Figure: Uncle Bob’s suggestion TDDing an algorithm. From https://twitter.com/peitor/status/200836812384641025
TDD against different Search APIs is #pain
For example
     BingSearch! 'My blog with my daily problems'    returned: 2
     BlekkoSearch! 'My blog with my daily problems'    returned: 1
     DaumSearch! 'My blog with my daily problems'    returned: 146538
     GigaBlastSearch! 'My blog with my daily problems'    returned: 1
     GoogleSearch! 'My blog with my daily problems'    returned: 1
     YahooSearch! 'My blog with my daily problems'    returned: 8
Figure: Search for 'My blog with my daily problems'. Result: Daum doesn't allow to search for whole sentences

     BingSearch! 'That’s the reason why you should do small checkins'    returned: 0
     BlekkoSearch! 'That’s the reason why you should do small checkins'    returned: 0
     DaumSearch! 'That’s the reason why you should do small checkins'    returned: 84
     GigaBlastSearch! 'That’s the reason why you should do small checkins'    returned: 0
     GoogleSearch! 'That’s the reason why you should do small checkins'    returned: 0
     YahooSearch! 'That’s the reason why you should do small checkins'    returned: 1
Figure: Another search: Result: Yahoo index is most up to date

Search APIs. Fake them all

-----------------------------------

Talk is cheap, show me the code
Linus Torvals

Here some tests for your pleasure. Those specify the method that splits text into smaller chunks.
public class TextSplitterSpecs

    [Test]
    public void ReturnSameString_IfWordsParamIsGreater()
    {
        const string twoWords = "Peter Gfader";
        var result = testSplitter.Split(twoWords, maxWords: 3);

        result.OnPosition(0).Should(Be.EqualTo(twoWords));
    }

    [Test]
    public void SplitString_IfWordsAreMoreThanParam()
    {
        const string twoWords = "Peter Gfader";
        var result = testSplitter.Split(twoWords, maxWords: 1);

        result.OnPosition(0).Should(Be.EqualTo("Peter"));
        result.OnPosition(1).Should(Be.EqualTo("Gfader"));
    }

    [Test]
    public void IgnoreWhiteSpace_BetweenSplitWords()
    {
        const string twoWords = "Peter                                    Gfader";
        var result = testSplitter.Split(twoWords, maxWords: 1);

        result.OnPosition(0).Should(Be.EqualTo("Peter"));
        result.OnPosition(1).Should(Be.EqualTo("Gfader"));
    }

The codez

TDD really helped me drive out the core business logic, which is the TextSplitter class.
That class splits text into smaller chunks of text, that I submit to the search engines.

public class TextSplitter
{

    public ICollection<string> Split(string stringToSplit, int maxWords)
    {
        if (string.IsNullOrEmpty(stringToSplit))
        {
            return new Collection<string>();
        }

        stringToSplit = ReplaceSpecialCharacters(stringToSplit);
        
        IEnumerable<string> sentences = Split(stringToSplit, 1, '.');
        
        ICollection<string> sentenceParts = Split(sentences, 1, ',');

        return Split(sentenceParts, maxWords, ' ');
        
    }

    private static string ReplaceSpecialCharacters(string stringToSplit)
    {
        stringToSplit = stringToSplit.Replace("\r\n", ".");
        stringToSplit = stringToSplit.Replace("\n", ".");
        stringToSplit = stringToSplit.Replace("\r", ".");
        stringToSplit = stringToSplit.Replace('?', '.');
        stringToSplit = stringToSplit.Replace('"', ' ');
        return stringToSplit;
    }

    private ICollection<string> Split(IEnumerable<string> sentenceParts, int maxWords, char separator)
    {
        ICollection<string> finalResult = new Collection<string>();
    
        foreach (var sentence in sentenceParts)
        {
            var temp = Split(sentence, maxWords, separator);

            foreach (var word in temp)
            {
                finalResult.Add(word);
            }
        }
        return finalResult;
    }


    private IEnumerable<string> Split(string stringToSplit, int maxWords, char separator)
    {
        if (string.IsNullOrEmpty(stringToSplit))
        {
            return new Collection<string>();
        }

        stringToSplit = RemoveDuplicateSpaces(stringToSplit);

        string[] arrayOfStrings = stringToSplit.Split(separator);
        if (arrayOfStrings.Length > maxWords)
        {
            var result = SplitByMaxWords(arrayOfStrings, maxWords);
            return result;
        }


        return new Collection<string> { stringToSplit };
    }

    private static IEnumerable<string> SplitByMaxWords(IEnumerable<string> arrayOfStrings, int maxWords)
    {
        var result = new Collection<string>();
        int i = 1;
        string word = string.Empty;
        foreach (var singleWord in arrayOfStrings)
        {
            word = word + " " + singleWord;
            if (i >= maxWords)
            {
                result.Add(word.Trim());
                word = string.Empty;
                i = 0;
            }
            i++;
        }

        // add last potential word
        // i>1
        if (!word.IsEmpty())
        {
            result.Add(word.Trim());
        }
        return result;
    }

}

Let me know if you smell any smells

VS2012RC

The UI of VS2012 RC is not as bad as I expected from all those blog posts
The VS2012 Solution Explorer needs more contrast I think

Figure: VS2012 RC Solution Explorer needs more contrast!

Overall Lesson learned

Coding is fun

My next steps?

More features for CopyCat

Yours?

Give CopyCat a go

Reporting: 13 questions to answer before getting started

noreply@blogger.com (Peter Gfader) — Wed, 06 Jun 2012 09:22:00 +0000

I get the following questions quite often and thought I gather my thoughts together in this blog post

“Which reporting components should we use in WPF?
Is it Infragistics, Telerik, syncfusion”
“Is DevExpress XtraReports Suite still state of the art for reporting?”
“Do you prefer SQL Server Reporting Services (SSRS) over Crystal Reports?”

Figure: Not sure if I should respond or remain silent

Before you can answer those question you need to step back and ask a couple of questions from a business point of view:

What question is the report(s) going to answer?
What decision does the report help to take?
What actions do we take after seeing the report?

Then we might get a bit more technical:

How up-to-date do the reports need to be?
Do you need to see a trend over these reports over time?

And then you should dig deeper

When and how should the reports be displayed?
Windows App, Web, In Application, Excel? (BA’s love Excel)
Who is the target group of the report?
Internal (authenticated) people only/extern?
What is the report data source?
SQL Server, Oracle, alle OleDB DB, data warehouses?
Who is creating the reports?
Developers? BAs? CXO? Technical User?
Who is going to maintain the reports?
Developers? BAs? CXO?
How often should we deliver the reports?
On demand, Scheduled, Trigger?
Are the reports fairly static of parameterized? Sub-reports?
Reports embedded in other applications. Parameters could be Dates, Departments, People, …
Is there already infrastructure of know how available?
Crystal oder MS Report server?

Depending from these answers I would suggest:

Infrastructure like SQL Server Reporting Services
SQL Reporting Services reports generated on the client side
Report Builder as a tool to develop and maintain reports
Sharepoint Server 2010 (was Microsoft PerformancePoint Server)
Excel Services deployed in Sharepoint
Control suite like: devExpress, telerik, syncFusion, Infragistics
Excel with a SQL or OLE DB datasource
Custom pages in ASP.NET

If some of these terms are new to you check out my slides on Reports with SQL Server Reporting Services on SlideShare
http://www.slideshare.net/PeterGfader/reports-with-sql-server-reporting-services

And SQL Server Analysis Services and Cube browser overview
http://www.slideshare.net/PeterGfader/ssas-other-cube-browsers

BTW: Adam has a great collection of Reporting Tips and Tricks

How do you approach such the questions at the top??

Silverlight - Testing the untestable

noreply@blogger.com (Peter Gfader) — Wed, 30 May 2012 10:54:00 +0000

Another limitation of testing Silverlight that me and one of my workmates ran into with mstest and VS2010 is documented below.
OOP especially Polymorphism help us here though.

We try to test a method that takes an ObservableCollection as input parameter.
I would like to leave the discussion about whether a method with a parameter of type "ObservableCollection" is a good idea or not to another day…

This is the method we want to write some tests around

        public static bool Swap(
                            ObservableCollection<int> sourceCollection, 
                            int index0, 
                            int index1)
        {
            //HACK Removed for blog 
            //TODO Swap ;-)
            return false;
        }

And this is the 1st test that we are going to write

        [TestMethod]
        public void WhenPassingNull_ShouldReturnNull()
        {
            Assert.IsFalse(Swapper.Swap(null, 0, 1));
        }

Visual Studio tells us

Figure: Trying to test a type that is in a Silverlight class library

SwapperTests.cs(20,13): error CS0012:
The type 'System.Collections.ObjectModel.ObservableCollection`1<T0>' is defined in an assembly that is not referenced.
You must add a reference to assembly 'System.Windows, Version=2.0.5.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e'.

Adding that reference is not easy as we will see..

You can try to copy and paste that reference

Figure: PowerCommands for Visual Studio 2010 allow you to easily copy and paste references between projects

but you might get this error

Figure: Error HRESULT E_FAIL has been returned from a call to a COM component.

…because that type is Silverlight specific and the Microsoft test framework doesn't support Silverlight.

BTW:
That's the reason we have the "Microsoft Silverlight unit test framework" which runs tests only in the browser.
This is useless for us cause we want to run tests on the build server and not in the browser

How can we solve this problem? And write tests for the above method?

If you use Collection<T> instead of ObservableCollection<T> then you can write tests around those methods. The Collection type has all methods you need.

ObservableCollection has an additional event for Silverlight ("NotifyPropertyChanged") but because of polymorphism all should be good!

Polymorphism FTW!

Passing in an ObservableCollection is fine, because it implements Collection.

Additionally all events fire under the hood, because it is still an ObservableCollection

On the road to BDD… Or… to see the light

noreply@blogger.com (Peter Gfader) — Wed, 11 Apr 2012 15:49:00 +0000

If you are a regular reader of this little blog in the middle of the internet, you might have realized that I am keen on “all things testing”. This is just a little experience report on my journey to better testing and getting everyone involved in the discussion about what we are building with our codez.

Figure: Everyone get together and collaborate

Story #1

On one of my projects in the past we happened to write a lot of tests that verify similar functionality that was very important for the business. It was so important that we as developers wanted to verify and check with the stakeholders and get a signature under the tests (signed with blood muahahaha).

Figure: Sign the tests, because they describe the system

To do so we needed to bring them in a format so they were easily readable. What I did then, was to write a T4 template that removed all C# noise and spit out a HTML file.

Figure: C# code gets converted to nicely formatted HTML code via T4

We (Devs and stakeholders) then sat together in front of a printed webpage and went through all scenarios. You can imagine the discussion and the help that this document provided.
Obviously every change on paper needed to be done by us devs in code.
It was very easy to regenerate the documentation… as you might think it is automated

Story #2

A couple of days ago I was doing a little Kata exercise (Tennis Kata) and thought to myself:
How would I write the test in Word or Notepad?

What I came up with was:

---
Simulate a TennisGame

Start new Game

P1 WinsBall
GameScore = 15:0

P2.WinsBall
GameScore = 15:15

P2.WinsBall
GameScore = 15:30

P1.WinsBall
GameScore = 30:30

P1.WinsBall
GameScore = 40:30

P1.WinsBall
P1 Wins The Game
----

This is very easy to read and understand for everyone who is a little bit familiar with Tennis.

When I had this in Notepad I copied it into a C# test project and wrote helpers and extension methods around this in order to make it compile-able.

What I got then was

        [Test]
        public void Simulate_A_TennisGame()
        {
            var tennisGame = StartNewGame();
            
            // Helpers
            var Game = tennisGame;
            var P1 = tennisGame.Player1;
            var P2 = tennisGame.Player1;


            P1.WinsBall();
            Game.Score.ShouldBe("15:0");

            P2.WinsBall();
            Game.Score.ShouldBe("15:15");

            P2.WinsBall();
            Game.Score.ShouldBe("15:30");

            P1.WinsBall();
            Game.Score.ShouldBe("30:30");

            P1.WinsBall();
            Game.Score.ShouldBe("40:30");

            P1.WinsBall();
            P1.WinsTheGame();  // --> Game.Score.ShouldBe("P1");


        }

I was quite happy with those extensions and helpers because they made all my tests very readable.

Conclusion

The result of both stories are nice readable tests that act as documentation with all the benefits of tests.

What is next for me is to use one of these "fancy" BDD frameworks, where you write your tests in clear text format…

My lesson learned: Start to write your tests on paper or NotePad! And “grow” from there…

BTW: Here is a nice article about the “differences” between BDD vs ATDD

Fast = $$$ How do you make sure to have a fast application?

noreply@blogger.com (Peter Gfader) — Sat, 25 Feb 2012 11:18:00 +0000

Many articles on the web, books and statistics tell us that “faster = better” and even more important: faster = more revenue.

For Google an increase in page load time from 0.4 second to 0.9 seconds decreased traffic and ad revenues by 20%.
For Amazon every 100 ms increase in load times decreased sales with 1%.

Also Google uses site speed in their web search ranking. So make sure to optimize your website for speed as per my other blog post.

Is Web Performance Optimization (WPO) something for you?

For one of my clients performance is critical. They need instant feedback (“real time!?”) in their application in order to run a smooth system. Otherwise their end users wouldn’t trust the system and not use it…

The system is a nifty application where people (with Silverlight) connect to a server (a WCF service) and we push out updates a couple of times per second. Yep, that’s in the 100ms range..

To reach a high level of performance we did a lot of performance tuning, including all my tips from optimize your website for speed as per my other blog post. More in general we try to reduce the numbers of database access and we keep everything in memory as much as possible. Did I mention caching?

Developers like to change things

We are continuously working on that project. We implement new features, we fix bugs we improve certain bits, or at least we think we improve them

How can we make sure that code changes don’t introduce a performance problem?

We need a “performance test”, or a “stresstest” or a “load test”.
Something that tests the performance our application.

My view of the difference between “Loadtest” and “Stresstest” can be found in my interview with loadstorm.

The problem with this “performance tests” is, that they usually take a bit of time to run. So running them on every check-in might not make sense.
So we decided to run them once a day, preferably during the night where we are not bothered with high server temperature because of CPU overload or a slow network because of network overload.

What is the final goal?

Get a thumbs up from our stresstest environment before releasing the latest to the wild!

The goal is to get a confirmation that we didn’t introduce a performance problem with our changes that we made during the day.
Every morning we get a report via email from SQL Server Reporting Services. This report shows us all important performance statistics about our system.

These are 2 reports from different days:

This is a good normal run (Click to enlarge)

Figure: Stresstest overview

Figure: System wide Statistics

Figure: Top 10 Process Statistics

This is a bad one

Figure: Drop of all connected users at 3:07AM with the consequence of CPU spiking

We have seen how important performance is and what the final goal is.
Next up:
How to setup this stresstest environment and this stresstest report. Topic of my next blog post.
Stay tuned!

BTW: Little info before hand
This report is done with:

VMWare
- 1 virtual machine for the stresstest server
- More virtual machines that act as clients
TFS & msdeploy
- Deploy latest version to stresstest environment
Perfmon
- Scheduled Perfmon from 3AM-5AM on the server
- Logs everything to a database
SQL Server Reporting Services
- Collects data
- Generate a report on top of those numbers

Do you have automated performance tests? Send me a tweet!

Conferences to attend this year - I love lists

noreply@blogger.com (Peter Gfader) — Thu, 02 Feb 2012 14:36:00 +0000

I love lists!
Or as my girlfriend says to me: "Don't you have a list for that?"

Indeed, I have a list for almost everything:

Things to read
Things to buy
Things to blog
Presents for Christmas 2012
Tools to play with
Lap times with my bike
...

This comes back to:
#1 What you don't measure, you cant improve -> Continuous Improvement
and
#2 What you write down, you don't have to remember -> Free up your mind

The other good thing is:
#3 "A list is a data structure" #wootwoot #DoubleGeekW00t

Back to the list that I wanted to bring up:

Conferences to attend 2012

This list is highly customized to my needs: Central Europe based, Developer Focused, Agile+Scrum related, No SharePoint, Easy to get to, Heaps of coffee there and maybe even Free?

How keen am I? In number of rainbows	Name, Date and URL
	QCon London March 5-9 http://qconlondon.com/
	Microsoft Windows TechConference 12. März 2012 \| Trafo Baden http://www.microsoft.com/switzerland/msdn/de/windowsconference/default.aspx
	Swiss testing day 14. März 2012 in Zürich http://www.swisstestingday.ch/
	Excellence in Software (David Starr and Elizabeth Woodward) http://eseconf.com/ 24-25 April, Zürich
	XP2012 May 21-25 2012 in Malmö Sweden http://xp2012.org/
	NDC 2012 June 6-8 http://www.ndcoslo.com/
	TechEd 2012 June 11-14 in Orlando US http://northamerica.msteched.com/
	JAZOON'12 Zurich, Switzerland June 26 to 28 http://jazoon.com/2012/Conference
	TechEd Europe June 26-29, Amsterdam http://europe.msteched.com/
	Scrum Day 2012 July 6, Walldorf, Germany http://www.scrum-day.de/
	Build 2012 Couldn't find an official date yet...
	ALE2012 Unconference 29-31 August 2012, Barcelona http://alenetwork.eu/blog/2012/01/10/ale2012-dates-and-place-announced/
	Lean Agile Scrum http://www.leanagilescrum.ch/ 12. September, Zürich
	iqnite - Software quality and testing 25. September Konferenz. Zürich http://www.iqnite-conferences.com/ch/index.aspx
	Oredev http://oredev.org/ I guess in November. Same as last year

More conferences can be found here.
Wow! This year is overwhelming!!!!

Scrum.org has a nice list with Agile events
http://www.scrum.org/events

Great list, run by Jean Pierre
http://www.scrum-events.de/

lanyrd – the social conference directory
http://lanyrd.com/calendar/

Swiss tech meetups can be found here
http://techup.ch/

Which conferences are you going to? And I should as well???

Tumblr! Not an excuse for not “blogging”

noreply@blogger.com (Peter Gfader) — Sun, 22 Jan 2012 10:42:00 +0000

Figure: … Comic effect created with this Photoshop tutorial

Is my new tumblr stream just an excuse for not blogging??
Instead of saying:

“I am way too ~~lazy~~ busy to write a proper blog. I just post random stuff”

No!
It is my effort of publishing more. As I said in my 2012 retrospective I want to publish more, because I like the feedback and discussions that come out of it.

So... there you have it: Peter’s little link list + comments

PS
Via feedburner I get all these “tumbles” in my inbox (special folder), so I can easily search for these notes later on…

PPS
Thanks to Juri for this

What do you think?