Human-Debugger.net

Dasblog 2.3 | GoDaddy.com

2010-02-13T05:49:30.4049487-07:00

Finally, after a long time I find time to upgrade my blog to the newly 2.3 version.

I had many problems installing this version Go-daddy, Monorail and SecurityException.
The last one was also the funny one, after Google-ing a little bit, I found this post by Gabel one of my co-workers.

What’s new?

So first I created my self a new homepage which you can see here.
Second, you can track my reading-list, my twitter statuses and my projects (will be published later).

Have fun.

Parameterize Tests - [TestCaseAttribute]

2009-07-31T21:20:12-07:00

Test methods must be written as production code.
While writing your tests you must act the same methods you write for your production code which means:

human-readable (code standard, pattern etc.)
code re-use (copy paste is never acceptable)
etc...

This is a code you will probably find in your test projects

               1: [Test]

               2:
              public
              void GetCommentsByQuery_LookFormHmmmText_FindAtLeaseOne()

               3: {

               4: SvnLogParser
parser = new SvnLogParser();

               5:
              string textToSearch
= "Hmmm...";

               6: var
results = parser.GetCommentsByQuery(comment => comment.Contains(textToSearch));

               7: CollectionAssertExtensions.IsNotEmpty(results);

               8: }

9:

               10: [Test]

               11:
              public
              void GetCommentsByQuery_LookFormBugText_FindAtLeastOne()

               12: {

               13: SvnLogParser
parser = new SvnLogParser();

               14:
              string textToSearch
= "bug";

               15: var
results = parser.GetCommentsByQuery(comment => comment.Contains(textToSearch));

               16: CollectionAssertExtensions.IsNotEmpty(results);

               17: }

You can see that the two methods are pretty much the same, the only change is the textToSearch variable.
There are some excuses for such duplication:

"We want two different names... to easily understand the failiure reason"
"we want it to be easy to read, without context switches..." (method calls and un-needed inheritance complexity)

We, of course, can refactor this code, like this:

               1: [Test]

               2:
              public
              void GetCommentsByQuery_LookFormBugText_FindAtLeastOne()

               3: {

               4:
              string textToSearch
= "bug";

               5: GetCommentsByQuery_AssertAllItemsStartsWith(textToSearch);

               6: }

7:

8:

               9: [Test]

               10:
              public
              void GetCommnentsByQuery_LookForHmmmText_VerifyInsideComment()

               11: {

               12:
              string textToSearch
= "Hmmm...";

               13: GetCommentsByQuery_AssertAllItemsStartsWith(textToSearch);

               14: }

15:

               16:
              public
              void GetCommentsByQuery_AssertAllItemsStartsWith(string textToSearch)

               17: {

               18: SvnLogParser
parser = new SvnLogParser();

               19: var
results = parser.GetCommentsByQuery(comment => comment.StartsWith(textToSearch));

20:

               21: CollectionAssertExtensions.AllItemsSatisfy(results,
res => res.Comment.StartsWith(textToSearch));

               22: }

This is better when you think of clone detection: less identical rows and the logic was extracted to one method.
But people might say that they can't see the AAA (Arrange, Act, Assert) and they want it in one place,
Moreover, in such code sample, it is harder to find all the input parameters, cause they will be spread all over the TestFixture methods.

NUnit 2.5 added TestCaseAttribute, this can help us write tests that are:

more readable
shorter test-fixture
all-in-one-place tests

               1: [TestCase("Hm...")]

               2: [TestCase("bug")]

              2: [TestCase("bug")]

               3:
              public
              void GetCommentsByQuery_LookForText_FindAtLeastOne(string textToSearch)

               4: {

               5: SvnLogParser
parser = new SvnLogParser();

               6: var
results = parser.GetCommentsByQuery(comment => comment.Contains(textToSearch));

               7: CollectionAssertExtensions.IsNotEmpty(results);

               8: }

Here you can avoid the duplication and you won't need to refactor your Tests to more than one method, while you still see them running using the given parameter,
for example when the second parameter will fail you will see this output:

------ Test started: Assembly: App.Tests.dll ------

TestCase 'App.Tests.NewFolder1.SvnLogParserTests.GetCommentsByQuery_LookForText_FindAtLeastOne("Hm...")'
failed: 
  Expected: True
  But was:  False
    C:\ShaniData\ProjectsByTitle\Delver\App.Tests\NewFolder1\SvnLogParserTests.cs(75,0): at App.Tests.NewFolder1.CollectionAssertExtensions.IsNotEmpty[T]
    C:\ShaniData\ProjectsByTitle\Delver\App.Tests\NewFolder1\SvnLogParserTests.cs(33,0): at App.Tests.NewFolder1.SvnLogParserTests.GetCommentsByQuery_LookForText_Find...


4 passed, 1 failed, 0 skipped, took 0.78 seconds (NUnit 2.5).

The output will point the given method and the parameter used - which will ease finding the error.
You can extend reading about the usage here

Refactoring and code reviews

2009-07-27T23:05:03.713-07:00

Yoav sent me this web site.

I like the idea of sharing knowledge,
I also like to read and learn from open sources.
This is even better: daily -public- code review...

StringTemplate Introduction

2009-07-08T00:13:57-07:00

For more background about when we use this API you can read my last post about Rendering Objects to Html

Simple Rendering of query:

               1: var
query = new StringTemplate("SELECT
$column$ FROM $table$;");

               2: query.SetAttribute("column", "name");

               3: query.SetAttribute("table", "User");

               4: var
data = query.ToString();

We will refactor this sample to handle the queries from an outside source:

               1: var
group = new StringTemplateGroup("SimpleTemplates",@"C:\Templates\TemplateEngineTestCase");

               2: var
query = group.GetInstanceOf("1_simple");

               3: query.SetAttribute("column", "name");

               4: query.SetAttribute("table", "User");

               5: var
data = query.ToString();

Rows 1,2 - loading the template data from a source file.

Here is the Template (1_simple.st):

//1_simple.st
SELECT $column$ FROM $table$;

Template Anonymous Type:

In the last template usage (1_simple.st) We bind the parameters using strings only. but we also have a better options: let's assume we wrote down such template:

//2_simpleObjects.st
Full Name: $Person.FirstName$ - $Person.LastName$

But let's assume that we don't have the Person class\instance, we can simply write it using the anonymous types:

               1: var
user = new {FirstName = "Shani",
LastName = "Raba"};

               2: var
group = new StringTemplateGroup("OOTempaltes", @"C:\Templates\TemplateEngineTestCase");

               3: var
query = group.GetInstanceOf("2_simpleObjects");

4:

               5: query.SetAttribute("Person",
user);

You can also use this kind of bindings for setting template-attributes from each one of the Person sub-classes.

Template list:

Till now it is all pretty simple to implement by yourself, but the real issue here is the List binding feature.
You can write such template:

//3_simpleLoop.st
$items: {num1|
    <li>$num1$li> }$
$end$

and bind the list using this code:

               1: var
templateFolder = new StringTemplateGroup("SimpleLoopTemplates", @"C:\Tempaltes\TemplateEngineTestCase");

               2: var
template = templateFolder.GetInstanceOf("3_simpleLoop");

3:

               4: template.SetAttribute("items", new List<string>
{"Shani", "Doron", "Nati", "Yossi"});

Conclusion:

The code is pretty simple, the templates engine implements good functionality and is well documented.
The StringTemplate syntax is easy to learn and well documented.
I still don't like it when I need to learn a new language\syntax - it will sharpen the newbie's curve.
StringTemplate is missing good Object2Template Designer.

Israeli Scrum user group 2009 (15.07.09)

2009-06-13T20:42:51-07:00

Dr. Alistair Cockburn will be in Israel.
I recommend you this user-group: Scrum Event. come and learn from the best.

See you there.

Rendering Objects to Html

2009-06-06T19:48:07-07:00

Background:

We are writing a new task for the ArcGis Explorer, this task needs to place images on the globe using its X,Y coordinates.
While for each instance on the globe we need to render its details as html.

Mission:

Rendering the objects to html, we are still didn't find the right place (on the server or on the client), but let assume that they both need to do the same job.

Ideas:

Render in code:
This is the naive way of thinking. while you are first thinking about this problem you might think to add the object an ToHtml() method.
Always think about the: Single Responsibility Principle (SRP).
You can still think about Writing an HtmlWriter or HtmlRenderer class that gets object and render the object using reflection or something else, but than you will find yourself indenting you JavaScript\html\CSS in C#, for example you can watch this code:
```
 1: var
items = new List<string>
{"Shani", "Doron", "Nati", "Yossi"};
```
```
 2: var
sb = new StringBuilder();
```
```
 3: items.ForEach(currentItem
=> 
```
```
 4: sb.AppendFormat("{0}
",
currentItem)
```
```
 5: );
```
```
 6:string data
= sb.ToString();
```
Let's think about the time we will need to change the UI from
to one with style or maybe even change the list to be styled as table...

XSL - is pretty more dynamic than code, isn't it?
So we are now looking for something more dynamic, something that we can read from a file so we can give it to our designer to play with the UI.
This lead us to the second option: at my past all our reports were rendered using XSL files, personally I don't like this option.
But the main reason is that we will need to serialize our objects to XML, while in most cases all you need is to render only few fields.

Let's found another Template Engine:
The first one I can think of is the MVC Engine or Brail. after some searching reading and Testing I found StringTemplate.
Here is a simple code for using the API:

 1: var
templateFolder = new StringTemplateGroup("SimpleLoopTemplate", @"\TemplateEngineTestCase\WinApp");

 2: var
template = templateFolder.GetInstanceOf("3_simpleLoop");

 3://here
we are binding our list to the template

 4: template.SetAttribute("items", new List<string>
{"Shani", "Doron", "Nati", "Yossi"});

 5: var
data = template.ToString();

and here is the template (file name: 3_simpleLoop.st):

 1: $items:
{num1|

 2:<li>$num1$li>

 3: }$

 4: $end$

Conclusion:

The StringTemplate give us an API to solve our problem - and using such code and template we can render our Models to different Views.

But is this API is easy or even stable?

In later posts we will see more samples using the StringTemplate.
Hopefully samples for using Brail too.

Writing Web-Resume

2009-04-10T21:56:02-07:00

I've been looking around for samples and some good advices for writing resumes and found this site: VisualCV

Mostly, I like this Engineer profile: http://www.visualcv.com/alex1
The really good part is the "code sample" section on the top-right corner...

Have fun...

NTS - Net Topology Suite

2009-04-10T14:15:45-07:00

Last month I've presented a simple newbie's tutorial about NTS - Net Topology Suite.
Here you can download the code sample & presentation.

What is it NTS (Net Topology Suite)?

implements geometry model defined in OpenGis Consortium (OGC)
implements simple features inside the OpenGis Consortium (OGC) as Geographic Data access
implements Some great OGC writers as: GmlWriter (Geographic markup language), WktWriter (Well Known Text)

How do I know whether I need NTS:

You are coding a GIS (Geographic Information Systems) applications
You want to use a known Convention for Point, Polygon, Polyline etc.
You want simple implementation for OGC

3 times No - you don't need this
3 times Yes - you must read this article and probably use it.

You can read more about Kml & C#3.0 - at my last post.
I will keep posting more samples in the near future.

Linq to XML (and Linq2Kml Bonus)

2009-04-10T14:03:14-07:00

This post inspired by Gal Ochana.

Gal is a new gifted programmer at my team, she presented a great presentation about Linq to XML - you can download code here.
The great bonus at her presentation was the Linq to Kml Sample, I would like to share this with you.

The kml itself is an XML file at our sample it looks like this:

               1:
              
              xml
              version
              ="1.0"
              encoding
              ="UTF-8"?>

               2:
              <
              kml
              xmlns
              ="http://www.opengis.net/kml/2.2"
              >

               4:
              <
              name
              continent
              ="America"
              >Americaname>

               5:
              <
              description
              >Attached
to the ground. Intelligently places itself at the height of the underlying terrain.description>

               7:
              <
              coordinates
              >-100.0822035425683,37.42228990140251,0coordinates>

               11:
              <
              name
              continent
              ="Africa"
              >Africaname>

               12:
              <
              description
              >Attached
to the ground. Intelligently places itself at the height of the underlying terrain.description>

               14:
              <
              coordinates
              >20.0822035425683,20.42228990140251,0coordinates>

               18:
              <
              name
              continent
              ="Asia"
              >Asianame>

               19:
              <
              description
              >Attached
to the ground. Intelligently places itself at the height of the underlying terrain.description>

               21:
              <
              coordinates
              >42.0822035425683,33.42228990140251,0coordinates>

               25:
              <
              name
              continent
              ="Europe"
              >Europename>

               26:
              <
              description
              >Europedescription>

               28:
              <
              coordinates
              >100.0822035425683,62.42228990140251,0coordinates>

You can read more about Kml here.

Screen-shot of the above kml in the ArcGis-Explorer:

You can see in the above Kml file sample the continents represented as a simple points, of course you can extend it to include polygons, poly-lines or anything else that valid within KML standard.
The only things that differs Kml from the known Xml file is the namespace that we will need to handle in our code, let's see the query itself:

               1: XNamespace
ns = "http://www.opengis.net/kml/2.2";

2:

               3: XDocument
kmlDoc = XDocument.Load(InputKml);

4:

               5: var
result = from placemark in kmlDoc.Descendants(ns
+ "Placemark")

               6:
              where (placemark.Element(ns
+ "name")

               7: .Attribute("continent").Value
==

               8: Continents.SelectedItem.ToString())

               9: select
placemark;

line 1: declare the full namespace that will be used for the attributes and Tags
line 3: loading the kml input file
line 5-9: run a simple query to select a single continent, pay attention to the namespace that we concatenate for selecting the right node.

Here you can see a screen-shot with the result of the above query using the "Asia" continent as the selected item.

Enjoy.

Alt.Net Israel #2

2009-03-26T04:50:24-07:00

Next Friday (3.4.09) will be the second alt.net conference
You can read more here about alt.net

Registration to the event at facebook

I'll be there.