1. Matiar Rahman
Project Manager
Binary Quest Limited

2. Agenda
What are Coding Standards?
Benefits of Automation
Standards Automation Tools
Use of StyleCop and FxCop

3. What are Coding Standards?
A set of rules or guidelines used when writing the
source code of a computer program.
Generally dictates:
Safety mandates to avoid introducing errors.
Style mandates to increase maintainability.
Security mandates to avoid vulnerabilities.
Efficiency mandates to help increase performance.
Standards may be enforced through code reviews or
may simply be “suggestions”.

4. Standards: Like or Dislike?

5. But, Isn’t Programming Art?
This always has been an interesting point of
contention.
On one extreme development can be thought of as a
work of art and any source that reaches a logically
correct result is acceptable and everything else is just
“style.”
The other extreme believes that programming is purely
a mechanical process and there is only a limited
number of correct answers.
Which is correct?

6. Reality Lies In Between
It may be more accurate to say developers are more
like artisans (crafters) than artists, though containing
elements of both.
An artist has a wide range of forms they can adhere to
and much is dependent on the interpretation of the
viewer.
In contrast, artisans tend to construct or design for a
purpose, and while there are some elements of style in
construction, if it fails to achieve its purpose
effectively, it is a failure.

7. The “Art” of Sorting
Take sorting, for example.
Both Bubble sort and Quick sort are valid sorts on a set
of data.
Bubble sort has a complexity of O(n2
) and Quick sort is
O(n log n).
Assuming sorting 1 million elements and each check
takes 1 µs, roughly this would be:
 Bubble Sort: 11 days
 Quick Sort: 19 seconds
Both sort data, but one is clearly more useful.

8. Standardizing an “Art”
While there are many ways to solve a given problem,
there should be guidelines for effective construction.
These guidelines are similar to building codes used in
building construction to ensure safety and quality.
These guidelines form the basis for coding standards
and are best compiled from group consensus and
industry best practices.

9. Enforcing Standards
Standards should be enforced to promote safety,
efficiency, and maintainability.
Standards can be enforced through Code Reviews, but
these tend to be applied with varying levels of
adherence.
It’s much better to attempt to automate as much of
your standards as possible so that the code is judged
more objectively.

10. Benefits of Automation
Standards are applied objectively since only analyzes
the source or assembly.
Just plain faster than trying to catch standards
violations manually.
Code authors don’t feel personally attacked.
Frees more reviewer time since won’t have to waste as
much time in code reviews.
Frees more time for developers since code spends less
time and iterations in review.

11. Standards Automation Tools
There are two primary tools from Microsoft:
StyleCop – Analyzes source files to determine if source
code is correctly formatted.
FxCop (Static Code Analysis)– Analyzes assemblies to
determine if code is constructed safely and optimally.
These tools overlap in some of their base rules but
both have their strengths.
Other third party and Microsoft tools exist, but
beyond this presentation’s scope.

12. FxCop, VS Code Analysis
Static analysis
Analyzes compiled assembly (dll, exe)
Finds violations of programming and design rules
 http://msdn.microsoft.com/en-us/library/3z0aeatx.aspx

13. Gendarme
Static analysis
Analyzes compiled assembly (dll, exe)
Finds violations of programming and design rules
 http://mono-project.com/Gendarme

14. NDepend
Analyses compiled assembly (dll, exe)
Measure, visualize and query source code quality
 http://www.ndepend.com/

15. Pex
Dynamic analysis
Analyzes code branches at runtime
Generates inputs to achieve max coverage
Generates test cases
 http://research.microsoft.com/en-us/projects/pex/

16. Code Contracts
Static checker
Analyzes compiled assembly (dll, exe)
Reports formal contract violations
 http://research.microsoft.com/en-us/projects/contracts/

17. FsCheck
Randomly generates test inputs
Generates test cases based on program specifications
Port of Haskell's QuickCheck
 http://fscheck.codeplex.com/

18. Simian
Analyzes source code
Detects duplication
http://www.harukizaemon.com/simian/index.ht
ml

19. StyleCop
Analyzes source files and not compiled code.
Great for checking elements such as:
Spacing
Comments
File composition
Naming
Cannot easily check type hierarchies or program
structure.
Available at http://stylecop.codeplex.com/

20. Configuring StyleCop
If you have StyleCop installed, you can have
Settings.StyleCop files for each project if you want to
vary styles per project.
Will take the first Settings.StyleCop file it finds from
working directory on up the path.
Default will be the Settings.StyleCop file in
c:program filesMicrosoft StyleCop…
Various configurations can make harder to enforce
uniform rules, though, so use with caution.

21. Configuring StyleCop
You can configure which base rules you want active by
using StyleCopSettingsEditor.exe.
Let’s take a minute to look at the rules…

22. Configuring StyleCop
You can also get to StyleCop settings in Visual Studio
directly by right-clicking a project.
This creates local copy of rules, use cautiously.

23. Running StyleCop
You can run StyleCop from VS or MSBuild.
Has no native command-line interface, but one exists
at sourceforge called StyleCopCmd.

24. StyleCop Results
Shows in Error List window, can turn on “Warnings as
Errors” in VS if you want to break builds on violations.

25. Suppressing a Rule
Most rules are good all the time, sometimes not.

26. On Suppressing Rules
It’s better to keep a rule even if it only applies 95% of
the time and force developers to suppress the rule for
the one-off exceptions.
This puts a SuppressMessage attribute in code
which must be justified and prevents viewing the
exception to the rule as a precedent for ignoring the
rule.
If code reviewer disagrees, can be debated.
Turning off rules should be avoided unless the rule is
invalid most or all of the time.

27. Custom StyleCop Rules
StyleCop rules are fairly easy to write.
Create class library that references the StyleCop
assemblies:
Located in c:program filesMicrosoft StyleCop…
 Microsoft.StyleCop.dll
 Microsoft.StyleCop.Csharp.dll
Add a CS (C# source file) for new analyzer.
Add an XML file for rule configuration.

28. Custom StyleCop Rules
In the CS file, create an analyzer that inherits from
SourceAnalyzer and has class attribute also named
SourceAnalyzer for C# files.s

29. Custom StyleCop Rules
In the CS file, override AnalyzeDocument and
perform your checks.

30. Custom StyleCop Rules
When you see your violation, call the method
AddViolation and give it a rule name and args:

31. Custom Style Cop Rules
Then, in the XML file, define the rule and message.
Make sure XML file has same name as class name and
is Embedded Resource.

32. Custom StyleCop Rules
Then, build the custom assembly.
Place custom assembly in:
C:Program FilesMicrosoft StyleCop …
You should now see custom rules in the
StyleCopSettingsEditor.
If you don’t see custom rules, check that the XML file:
Is an embedded resource
Has same filename as the class name (minus
extensions)
Let’s look at the code more closely…

33. StyleCop for ReSharper
JetBrains’s ReSharper is an Visual Studio IDE plug-in
that adds a lot of refactoring and aids.
StyleCop for ReSharper is a ReSharper plug-in that
allows for dynamic checking of StyleCop rules as you
type.
Will highlight rule violations with squiggle just like
other ReSharper hints.
http://stylecopforresharper.codeplex.com/
Let’s look at how this appears in the IDE.

34. FxCop (aka VS Code Analysis)
Great for checking elements such as:
Non-spacing style issues (naming, etc).
Code safety and performance issues
Type hierarchy issues
Analysis of database objects
Cannot check source style such as spacing.
Already baked into Visual Studio 2008/10.
Can also be used as a stand-alone.

35. Running FxCop Stand-Alone
Start  Programs Microsoft FxCop
Create new project, add targets, and Analyze!

36. Running FxCop From Visual Studio
Right click on project or solution and choose Run
Code Analysis:
Let’s look at an example analysis.

37. Suppressing FxCop Errors
Just like in StyleCop, you can suppress one-off
exceptions to the rules.
Can insert manually or automatically from the error
list in Visual Studio.

38. Custom FxCop Rules
Create a Class Library in Visual Studio.
Add references to FxCop assemblies:
From C:Program FilesMicrosoft FxCop…
 FxCopCommon.dll
 FxCopSdk.dll
 Microsoft.Cci.dll
 Microsoft.VisualStudio.CodeAnalysis
Add a CS file for the new rule.
Add an XML file for the rule definition.

39. Custom FxCop Rules
In CS file create class that inherits from
BaseIntrospectionRule:

40. Custom FxCop Rules
In CS File, override Check to check rule.

41. Custom FxCop Rule
XML file is Embedded and contains rule detail:
Remember filename must be same as passed to base
constructor of BaseIntrospectionRule.

42. Custom FxCop Rules
To use custom rule, use CTRL+R or Project  Add
Rules in FxCop.
You can verify by clicking on rules tab:

43. Summary
Automating code standards can be very useful for
getting rid of a lot of the “noise” in code reviews and
allowing reviewers to concentrate on logic bugs.
Automated code standards take the personal side out
of enforcing style, safety, and performance.
Custom rules can be used in FxCop and StyleCop to
allow for your own rules.