A Modern Architecture ReviewUsing Code Review Tools

Delivering Awesome Web Applications

@AdamCogan | #vsalm #tee12 #dev324

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Agenda• #1 The 1st things to look out for

• Processes• Does it work?• Documentation

•#2 High Level tools• Architecture• Code Analysis• Code Metrics

•#3 Manual Checking• SOLID Design Principles• Code Review tools

Chief Architect at SSW Developing custom solutions for

businesses across a range of industries such as Government, banking, insurance

Microsoft Gold Partner Microsoft Regional Director VSTS MVP @AdamCogan

About Adam

I Believe

The first things to look out for

Do you evaluate the processes? Often times this is the source of problems

Are devs getting bogged down in the UI? Do you have a Scrum Master? Do you have continuous integration? Do you have continuous deployment? Do you have a Schema Master? Do you have a TFS Master?

http://rules.ssw.com.au/SoftwareDevelopment/RulestobetterArchitectureandCodeReview/Pages/DoYouHaveTheDesignersFixingUpTheUI.aspx

Are they on the latest version? …of VS …of TFS Alternatively for a ‘Gold Star’ …

Resharper, add-ins, extensions

http://rules.ssw.com.au/SoftwareDevelopment/RulestobetterArchitectureandCodeReview/Pages/CanYouGetLatestAndCompile.aspx

Can you ‘Get latest’ and compile? #L1 It's amazing how often you can't simply do a "Get

Latest" and compile Add _Instructions_Compile.docx

Then run unit tests…

http://rules.ssw.com.au/SoftwareDevelopment/RulestobetterArchitectureandCodeReview/Pages/CanYouGetLatestAndCompile.aspx

Can you get latest and compile? #L1 See the Integration.Test project fail Add _Instructions_Compile.docx

http://rules.ssw.com.au/SoftwareDevelopment/RulestobetterArchitectureandCodeReview/Pages/CanYouGetLatestAndCompile.aspx

Can you get latest and compile? #L2 Creation of the database via scripts (incremental)

Tip: use OSQL, SQLCMD or SSW SQL Deploy and re-run the tests. They will now pass.

Do you want a ‘Gold Star’ ? #L3 Streamline setup of a new development environment Problems to check for:

Windows 8 not supported Many things to build Lots of dependencies

Recommendation: All manual work station setup steps should be scripted with PowerShell

Recommendation: A get + compile should work within 1 minute, and work without a dev being on the domain (to support external consultants)

Figure: You see the problems in the devs environmentNote Prefix eg. _01Setup-Environment.ps1

PS C:\Code\Northwind> .\Setup-Environment.ps1

Problem: Azure environment variable run state directory is not configured (_CSRUN_STATE_DIRECTORY). Problem: Azure Storage Service is not running. Launch the development fabric by starting the solution. 

WARNING: Abandoning remainder of script due to critical failures. To try and automatically resolve the problems found, re-run the script with a -Fix flag.

Figure: The script tries to automatically fix the problems

PS C:\Code\Northwind> .\Setup-Environment.ps1 -fix

Problem: Azure environment variable run state directory is not configured (_CSRUN_STATE_DIRECTORY).Fixed: _CSRUN_STATE_DIRECTORY user variable set Problem: Azure Storage Service is not running. Launch the development fabric by starting the solution.WARNING: No automated fix available for 'Azure Storage Service is running' 

WARNING: Abandoning remainder of script due to critical failures.

Figure: Note on 2nd run only 1 script remains – see there is less to fix

PS C:\Code\Northwind> .\Setup-Environment.ps1 -fix

Problem: Azure Storage Service is not running. Launch the development fabric by starting the solution.WARNING: No automated fix available for 'Azure Storage Service is running'

WARNING: Abandoning remainder of script due to critical failures.

Can you ‘Check In’ and Deploy #L1 Add _Instructions_Deploy.docx Alternatively for a ‘Star’ …

http://rules.ssw.com.au/SoftwareDevelopment/RulestobetterArchitectureandCodeReview/Pages/Default.aspx

Can you ‘Check In’ and Deploy #L2 Use PowerShell scripts as your documentation

build.ps1 deploy_dev.ps1 deploy_test.ps1 deploy_prod.ps1

Alternatively for a ‘Gold Star’ … TFSBuild + Portal

http://rules.ssw.com.au/SoftwareDevelopment/RulestobetterArchitectureandCodeReview/Pages/Default.aspx

Can you ‘Check In’ and Deploy #L2TFSBuild + Portal

Do you review the Solution and Project names? The name of your solution and the names of the

project in your solution should be consistent

http://rules.ssw.com.au/SoftwareDevelopment/RulestobetterArchitectureandCodeReview/Pages/DoYouReviewTheSolutionName.aspx

Do you review the documentation? Old School:

Heavy, long documents Sequence Diagrams UML

http://rules.ssw.com.au/SoftwareDevelopment/RulestobetterArchitectureandCodeReview/Pages/DoYouReviewTheDocumentation.aspx

Suggestions for doco eg. Enterprise Architect Use Red for unimplemented stuff Use the DateTime shape

To see the last time the diagram was modified and by whom

Mark items as ‘TODO: Adam’. For items still pending

Do you review the documentation New School:

4 docs• Business.docx• _Instructions_Compile.docx• _Instructions_Deploy.docx• Technologies.docx

Unit Tests (low level) Code and Work Items (low level PBI)

Vote:

High Level Tools

Agenda• #1 The 1st things to look out for

• Processes• Does it work?• Documentation

•#2 High Level tools• Architecture• Code Analysis• Code Metrics

•#3 Manual Checking• SOLID Design Principles• Code Review tools

Do you look at the architecture? 2 Choices:

VS Dependency Graph or … ?• Ultimate Edition

nDepend ?• 3rd Party Tool for a few hundred $ • Weak dependency graph• No need for VS Ultimate• Bonus: See problems in the ‘Queries + Rules Explorer’

http://rules.ssw.com.au/SoftwareDevelopment/RulestobetterArchitectureandCodeReview/Pages/DoYouLookAtTheArchitecture.aspx

My Dream

My Dream – instead of this

My Dream – it automatically does this

Great Overview tool and learning toolNot for day-to-day use as a code analysis tool.Note: Don’t be distracted by a colour problem

Do you use the best Code Analysis tools?

http://rules.ssw.com.au/SoftwareDevelopment/RulestobetterArchitectureandCodeReview/Pages/DoYouDoCodeAnalysis.aspx

Do you use the best Code Analysis tools? Level 1 – ReSharper – All Rules Level 2 - VS Code Analysis (FXCop) – Default Settings Level 3 - VS Code Analysis (FXCop) – All Rules Level 4 – StyleCop – All Rules Level 5 – SSW Code Auditor – All Rules

?

http://rules.ssw.com.au/SoftwareDevelopment/RulestobetterArchitectureandCodeReview/Pages/DoYouDoCodeAnalysis.aspx

Do you use the best Code Analysis tools?

http://rules.ssw.com.au/SoftwareDevelopment/RulestobetterArchitectureandCodeReview/Pages/DoYouDoCodeAnalysis.aspx

Do you use the best Code Analysis tools? Level 1 – ReSharper – campsite scout rule Level 2 - VS Code Analysis (FXCop) – Default Settings Level 3 - VS Code Analysis (FXCop) – Custom Level 4 – StyleCop Level 4 – StyleCop - Custom Level 5 – SSW Code Auditor Level 5 – SSW Code Auditor - Custom TIP: Have a document with rules that you turn off and the reason

http://rules.ssw.com.au/SoftwareDevelopment/RulestobetterArchitectureandCodeReview/Pages/DoYouDoCodeAnalysis.aspx

ReSharper

Resharper Custom

Code Analysis

Code Analysis Custom

Code Analysis – Suppress #1Add in ‘Suppression File’ or in code?

?

Code Analysis – Suppress #2

Add in ‘Suppression File’ or in code? Rule No Good – removed from Rule Set Rule N/A in this case – in ‘Suppression File’ Rule is Valid – in this case I am overriding it

Code Analysis – Create work item #1Add as Bug, PBI or Task...

?

Code Analysis – Create work item #2Neno’s solution = Select 30 in a PBI Leave as warningAussie solution = 1 becomes a PBI

StyleCop

Code Auditor

Rules turned off

Do you check the code coverage? See if there are unit tests See if they are any good (~ 80% coverage)

http://rules.ssw.com.au/SoftwareDevelopment/RulestobetterArchitectureandCodeReview/Pages/DoYouLookForCodeCoverage.aspx

Report time? If you are doing a report, gather some more reports…

Eg. Code Metrics, Code Coverage, Code Clones

But lets assume we are continuing to ‘Probe’… So from: SRP … … Naming Conventions

Our solution is clean now. What next?

Agenda• #1 The 1st things to look out for

• Processes• Does it work?• Documentation

•#2 High Level tools• Architecture• Code Analysis• Code Metrics

•#3 Manual Checking• SOLID Design

Principles• Code Review tools

Do you run Code Metrics to find dodgy code? Use the “Hot Spots” feature to quickly identify

smelly code It measures:

Maintainability Index Cyclomatic Complexity Depth of Inheritance Class Coupling Lines of Code

Code Metrics Results

Manual Checking:Getting our hands dirty

Manual Review After using the automated high level tools it’s

time to actually jump into the code Look for code that doesn’t follow SOLID

principles… and then design patterns Speak to the devs

SOLID Principles Single Responsibility Principle Open Close Principle Liskov Substitution Principle Interface Segregation Principle Dependency Inversion Principle

http://rules.ssw.com.au/SoftwareDevelopment/RulestobetterArchitectureandCodeReview/Pages/DoYouKnowCommonDesignPrinciples.aspx

Single Responsibility Principle A class should have one and only one responsibility

public class Address { // Standard Address Properties public Image GetGoogleMaps() {} public decimal GetDistance(Address destination) {} public bool ValidateAddress() {}}

Single Responsibility Principle The Address class has too many responsibilities

Showing an image of the address (tied to UI) Calculations based on the address Validation of the address

Another UI may use BingMaps instead of Google Maps

Some, if not all of these functions should be moved to other classes like MapHelper and AddressHelper

Single Responsibility Principlepublic class AddressHelper { public decimal GetDistance(Address start, Address destination) {} public bool ValidateAddress(Address address) {}}public class GoogleMapProvider : IMapProvider { public Image GetMap(Address start) {}}

public class BingMapProvider : IMapProvider { public Image GetMap(Address start) {}}

Open Closed Principle Open for extension, but closed for modification

Use Abstract base classes that specify some base functionality

E.g. In .NET WebRequest allows you to connect servers via web protocols HttpWebRequest FtpWebRequest FileWebRequest

Liskov’s Substitution Principle Subtypes must be substitutable for their base typespublic abstract class Duck { public abstract void Quack();}

Liskov’s Substitution Principlepublic class PekinDuck : Duck { public void Quack() {}}

public class BatteryPoweredDuck : Duck{ public BatteryPoweredDuck(Battery energizer) {} public void Quack() {}}

Can’t swap PekinDuck with BatteryPoweredDuck because you need pass it some batteries first

Another examplepublic class Rectangle { protected int _width; protected int _height; public int Width { get { return _width; } public int Height { get { return _height; } public void SetWidth(int width) { _width = width; } public void SetHeight(int height) { _height = height; }}

public class Square : Rectangle { public override void SetWidth(int width) { _width = width; _height = width; } public override void SetHeight(int height) { _width = height; _height = height; }}

Another Example (cont…) If we try to use these classes

var shape = new Rectangle();shape.SetWidth(2);shape.SetHeight(5);Console.WriteLine(String.Format(“Area = {0}”, shape.Height * shape.Width))// Prints 10 as expected (2 * 5 = 10)

Another Example (cont…) If we try the Squarevar shape = new Square();shape.SetWidth(2);shape.SetHeight(5);Console.WriteLine(String.Format(“Area = {0}”, shape.Height * shape.Width))// Prints 25 not as expected since we set the Width = 2 and Height = 5

Another Example (cont..)The Square violates the Liskov substitution principle as we don’t get expected behaviour as setting the width will also modify the height and vice versa

Interface Segregation Principle Don’t create interfaces with lots of methods that

don’t necessarily get used in their implementationspublic interface IBird {

public void Chirp(); public void Flap(); public void Fly(); public void Eat();}

public class MockingBird : IBird { public void Chirp() {} public void Flap() {} public void Fly() {} public void Eat() {}}

Interface Segregation Principlepublic class Emu : IBird { public void Chirp() {} public void Flap() {} public void Fly() {} public void Eat() { throw new NotImplementedException(); }}

Interface Segregation Principle

public interface IBird { public void Chirp(); public void Flap(); public void Eat();}

public interface IFlyingBird : IBird { public void Fly();}

public class Emu : IBird { public void Chirp() {} public void Flap() {} public void Fly() {}}

Dependency Inversion PrincipleDepend on abstractions, not on implementations. Anything required to create a valid instance of an object, should have those dependencies passed in as arguments to the constructor

Higher level classes to depend on abstractions of lower level classes (swappable)public class Employee { public Employee() { FavCoffee = new Cappuccino(); Skills = new List<Skills> { new MSAccessSkill(), new SharePointSkill(), new DotNetNukeSkill() } } }

Dependency Inversion Principlepublic class Employee { public Employee(IDrinkable iamthirsty, IEnumerable<Skills> skills) {} }

Dependency Inversion Principle

var MarkLiu = new Employee( CoffeeFactory.Get(“Skim Cappuccino”), new List<Skills> { new MSAccessSkill(), new SharePointSkill(), new DotNetNukeSkill() });

var EricPhan = new Employee( CoffeeFactory.Get(“Latte”), new List<Skills> { new BusinessIntelligenceSkill(), new MVC4Skill(), new DotNetSkill() });

Do you know the common Design Patterns? ?“Communicate massive amount of data in a few words” Adam Cogan

“Accepted solutions to well known problems” Ben Day

http://rules.ssw.com.au/SoftwareDevelopment/RulestobetterArchitectureandCodeReview/Pages/DoYouKnowCommonDesignPatterns.aspx

Do you know the common Design Patterns? Inversion of Control Dependency Injection Factory Singleton Repository Unit of Work MVC MVP MVVM

http://rules.ssw.com.au/SoftwareDevelopment/RulestobetterArchitectureandCodeReview/Pages/DoYouKnowCommonDesignPatterns.aspx

Abstract factory Adapter Bridge Mediator Proxy Flyweight Chain of

responsibility Command Memento

Iterator Visitor State Composite Facade Observer Decorator Null object Interpreter

Anti-Patterns

Abstractness vs Instability Diagram Shows the assemblies that are painful to maintain

i.e concrete and stable, and which assemblies are potentially useless i.e abstract and instable

Abstract: The assembly contains many abstract types (i.e interfaces and abstract classes) and few concrete types

Stable: The assembly is considered stable if its types are used by a lot of types of tier assemblies. In this condition stable means painful to modify.

Do you start reading code? Comments Q:\ Good or Bad? Comments are a smell Includes comments that explain the intent (the

why rather than the what)

Do you start reading code? Is clear and easy to read Has consistent and meaningful names for

everything Has no duplicate or redundant code Has consistent styles and formatting Explains "why" when you read down, and "how"

when you read left to right

http://rules.ssw.com.au/SoftwareDevelopment/RulestobetterArchitectureandCodeReview/Pages/DoYouStartReadingCode.aspx

Do you know Code Reviews after check in are bad? If you are aiming to get the to nirvana of

Continuous Deployment, then you cant *rely* on code reviews after the fact.

Code Reviews have different status:* Important* Nice to have

The Scenario Mark is migrating from DotNetNuke to MVC He’s unsure of his code because he doesn’t know

Razor Add some code with a comment ‘this could be

done better’ Checks in anyway

Use the Code Review tools in TFS 2012 TFS 2012 has built in Code Review tools Hooks into the check-in/shelving process This allows code to be manually reviewed before

checking in

Suspend current changes

Request a Review

Assign Reviewer

Reviewer Gets the Request

Check out the changeset

Related work items

Modified files

Shows the changed code

Side by Side (Standard Diff)

#1#2

Finalizing the Code Review

Check the Code Review

Check any comments

View code marked for review

Mark any flagged code as completed

Mark the Code Review as Complete

Code Review Summary Today: Developer does some work and wants to

get it checked before committing to source control Suggestion to MS: Add a new scenario

No touching of code Architect ‘Adds comments’ during code review Automatically adds the developers who originally

worked on that section (instead of manually using annotate)

Creates “Code Review” work items

http://www.ssw.com.au/ssw/Standards/BetterSoftwareSuggestions/TeamFoundationServer.aspx

Resources Thanks: Eric Phan and Adam Stephensen Thanks: Marcel De Vries and Terje Sandstrom

Google: ssw tv architecture code reviews

http://rules.ssw.com.au/SoftwareDevelopment/RulestobetterArchitectureandCodeReview/

Summary• #1 The 1st things to look out for

• Processes• Does it work?• Documentation

•#2 High Level tools• Architecture• Code Analysis• Code Metrics

•#3 Manual Checking• SOLID Design Principles• Code Review tools

Evaluations + 2 things Include best tip or tool you heard. Plus your tip to

me.

@adamcoganOrAdamCogan@ssw.com.au

Come and visit me (+ Sydney .NET User Group)

Delivering Awesome Web Applications

Thank You!Sydney | Melbourne | Brisbane | Adelaide

info@ssw.com.au

www.ssw.com.au

Questions? Take a business card.

Refactoring Level 1: Minimum Level 2: Custom

Note: All disabled ones to be documentedeg. http://www.benday.com/2010/03/15/article-static-methods-are-a-code-smell/

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