clean code iii - software craftsmanship
DESCRIPTION
You will learn why naming is really difficult if done right, why coding and style guidelines are crucial, code structuring, exception handling and why other elements of coding often define the tipping point between success and failure of projects. Following the principles of software craftsmanship will allow you to end up with better maintainability and extensibility of your software and the success of the project in the end. All 3 Clean Code presentations provide great value by themselves, but taken together are designed to offer a holistic approach to successful software creation. Why writing Clean Code makes us more efficient Over the lifetime of a product, maintaining the product is actually one - if not the most - expensive area(s) of the overall product costs. Writing clean code can significantly lower these costs. However, writing clean code also makes you more efficient during the initial development time and results in more stable code. You will be presented design patterns and best practices which will make you write better and more easily maintainable code, seeing code in a holistic way. You will learn how to apply them by using an existing implementation as the starting point of the presentation. Finally, patterns & practices benefits are explained. This presentation is based on C# and Visual Studio 2013. However, the demonstrated patterns and practice can be applied to every other programming language too. Note: Moving forwards this presentation will be updated with the latest version of the slides for the last event I did the presentation instead of creating new separate slide decks here on slideshare. Presentation dates and locations: 2014-11-14 SoCal Code Camp - Los Angeles, CA 2014-10-18 Desert Code Camp - Chandler, AZTRANSCRIPT
Clean Code III
Chandler, Oct. 18th, 2014
Software Craftsmanship
Desert Code Camp 2014.2
Theo Jungeblut• Engineering manager & lead by day
at AppDynamics in San Francisco
• Coder & software craftsman by night, first time dad and house builder
• Architects decoupled solutions & crafts maintainable code to last
• Worked in healthcare and factory automation, building mission critical applications, framework & platforms
• Degree in Software Engineeringand Network Communications
• Enjoys cycling, running and eating [email protected]
www.designitright.net
We are hiring!http://www.appdynamics.com/ careers
and there are much more positions
Your feedback is important!
http://www.speakerrate.com/theoj
Where to get the Slides
http://www.slideshare.net/theojungeblut
Overview
• Why Clean Code?• The Power of Simplicity• Tools - Your Best Friend• From Names to Classes• The "Must Read"-Books• Summary• Q&A
Does writing Clean Code make us more efficient?
The only valid Measurement of Code Quality
What is Clean Code?
Clean Code is maintainable
Source code must be:• readable & well structured• extensible• testable
Software Engineering
&Software
Craftsmanship
The “Must Read”-Book(s)by Robert C Martin
A Handbook of Agile Software Craftsmanship
“Even bad code can function. But if code isn’t clean, it can bring a development organization to its knees.”
Code Maintainability *
Principles Patterns Containers
Why? How? What?
Extensibility Clean Code Tool reuse
* from: Mark Seemann’s “Dependency Injection in .NET” presentation Bay.NET 05/2011
Keep it simple, stupid(KISS)
KISS-Principle – “Keep It Simple Stupid”
http://blogs.smarter.com/blogs/Lego%20Brick.jpg
by Kelly Johnson
The Power of Simplicity
http://www.geekalerts.com/lego-iphone/
Graphic by Nathan Sawaya courtesy of brickartist.com
Graphic by Nathan Sawaya courtesy of brickartist.com
Chaos build from simplicity
Graphic by Nathan Sawaya courtesy of brickartist.com
Source Code Conventions
.NET Tools and their ImpactTool name Positive Impact Negative Impact
Resharper compiling ++++, learning +++
VS responsiveness --
FxCop code quality ++ compiling time -
StyleCop code consistency +++ compiling time -
StyleCop plugin for Resharper
compiling time +++ VS responsiveness --
Ghost Doc automated docs potentially worse doc
Spell Checker fewer spelling errors ++ performance --
Code Contracts testability, quality ++ compiling time --
Code Digger automated test ++ compiling time --
Resharper
Features:– Code Analysis – Quick Fixes– Code Templates – Code Generation– Code Cleanup– Many, many more…
“The single most impacting development addition to Visual Studio”
http://www.jetbrains.com/resharper/
FxCop / Static Code Analysis
Code Analysis:– Correctness– Library design– Internationalization and localization– Naming conventions– Performance– Security
http://msdn.microsoft.com/en-us/library/3z0aeatx.aspx
Style Cop with R# Integration
Code Consistency & Readability:– Automated check of C# coding standard– Enforceable at check-in with TFS check-in
Policy
– Full Integration in Resharper with Style Cop plugin:
– Code Analysis – Quick Fixes– Code Cleanup
http://submain.com/products/ghostdoc.aspx
• Save keystrokes and time• Simplify documenting your code• Benefit of the base class documentation• Source code and text spellcheck (Pro version)• API documentation creation (Pro version)
Ghost Doc
Spell Checker
http://visualstudiogallery.msdn.microsoft.com/7c8341f1-ebac-40c8-92c2-476db8d523ce/
• Spelll chicking for literals and comments in VS
http://msdn.microsoft.com/en-us/devlabs/dd491992
• Design-by-Contract programming• Improved testability• Static verification• API documentation integration with Sandcastle
• Pex automatically generates test suites with high code coverage.
• Moles allows to replace any .NET method with a delegate.
Flakes (Microsoft Pex & Moles)
http://research.microsoft.com/en-us/projects/pex/
Names Matter
• Meaningful Names• Intention Revealing Names• Use Pronounceable Names• Use Searchable Names• Avoid Encoding (Hungarian)• Don’t be cute• Pick One Word per Concept• Use Problem Domain Names
* Chapter extract: Robert C. Martin –” Clean Code”, Parson Education, Inc. 2008
Functions
• Small – Do One Thing• One Level of Abstraction• No or only few Arguments• Have No Side Effects• Prefer Exceptions to
Returning Error Codes• Don’t Repeat Yourself
* Chapter extract: Robert C. Martin –” Clean Code”, Parson Education, Inc. 2008
Comments
• Comments do not Make Up for Bad Code• Explain Yourself in Code• Clarification• Warning of Consequences• ToDo Comments• Javadocs in Public APIs
* Chapter extract: Robert C. Martin –” Clean Code”, Parson Education, Inc. 2008
Bad Comments
• Mumblings• Redundant Comments• Misleading Comments• Journal Comments• Noise Comments• Don’t use a Comment When you Use a
Method or a Variable• Commented-Out Code
* Chapter extract: Robert C. Martin –” Clean Code”, Parson Education, Inc. 2008
The Purpose of Formatting
• Team Rules – Consistency is King• Vertical Openness Between Concepts• Vertical Distance• Horizontal Alignment• Indentation• Write Journey Style Code
Resharper & StyleCop – “Code Cleanup”
* Kind of Chapter extract: Robert C. Martin –” Clean Code”, Parson Education, Inc. 2008
Classes
• Class Organization • Encapsulation• Classes Should be Small• The Single Responsibility Principle• Cohesion• Organize for Change• Insolating from Change
* Kind of Chapter extract: Robert C. Martin –” Clean Code”, Parson Education, Inc. 2008
The “Must Read”-Book(s)by Robert C Martin
A Handbook of Agile Software Craftsmanship
“Even bad code can function. But if code isn’t clean, it can bring a development organization to its knees.”
The “Must Read”-Book(s)by Krzysztof Cwalina, Brad Abrams
Framework Design Guidelines
“teaches developers the best practices for designing reusable libraries for the Microsoft .NET Framework.”
Summary Clean Code
Maintainability is achieved through:
• Readability (Coding Guidelines)
• Simplification and Specialization (KISS, SoC, SRP, OCP, )
• Decoupling (LSP, DIP, IHP, Contracts, LoD, CoP, IoC or SOA)
• Avoiding Code Bloat (DRY, YAGNI)
• Quality through Testability (all of them!)
Downloads, Feedback & Comments:
Q & A
Graphic by Nathan Sawaya courtesy of brickartist.com
[email protected] www.speakerrate.com/theoj
References… http://clean-code-developer.comhttp://michael.hoennig.de/2009/08/08/clean-code-developer-ccd/http://butunclebob.com/ArticleS.UncleBob.PrinciplesOfOodhttp://www.manning.com/seemann/http://en.wikipedia.org/wiki/Keep_it_simple_stupidhttp://picocontainer.org/patterns.htmlhttp://en.wikipedia.org/wiki/Separation_of_concernshttp://en.wikipedia.org/wiki/Single_responsibility_principlehttp://en.wikipedia.org/wiki/Information_hidinghttp://en.wikipedia.org/wiki/Liskov_substitution_principlehttp://en.wikipedia.org/wiki/Dependency_inversion_principlehttp://en.wikipedia.org/wiki/Open/closed_principlehttp://en.wikipedia.org/wiki/Law_Of_Demeterhttp://en.wikipedia.org/wiki/Don't_repeat_yourselfhttp://en.wikipedia.org/wiki/You_ain't_gonna_need_ithttp://en.wikipedia.org/wiki/Component-oriented_programminghttp://en.wikipedia.org/wiki/Service-oriented_architecturehttp://www.martinfowler.com/articles/injection.htmlhttp://www.codeproject.com/KB/aspnet/IOCDI.aspxhttp://msdn.microsoft.com/en-us/magazine/cc163739.aspxhttp://msdn.microsoft.com/en-us/library/ff650320.aspxhttp://msdn.microsoft.com/en-us/library/aa973811.aspxhttp://msdn.microsoft.com/en-us/library/ff647976.aspxhttp://msdn.microsoft.com/en-us/library/cc707845.aspxhttp://msdn.microsoft.com/en-us/library/bb833022.aspxhttp://unity.codeplex.com/http://www.idesign.net/idesign/DesktopDefault.aspx?tabindex=5&tabid=11
… more ReferencesResharperhttp://www.jetbrains.com/resharper/
FxCop / Code Analysis http://msdn.microsoft.com/en-us/library/bb429476(VS.80).aspxhttp://blogs.msdn.com/b/codeanalysis/http://www.binarycoder.net/fxcop/index.html
Code Contractshttp://msdn.microsoft.com/en-us/devlabs/dd491992http://research.microsoft.com/en-us/projects/contracts/
Fakes (Previous Moles & Pex)http://www.richonsoftware.com/post/2012/04/20/Comparing-Microsoft -Moles-in-Visual-Studio-2010-to-Microsoft-Fakes-in-Visual-Studio-11.aspxhttp://research.microsoft.com/en-us/projects/pex/
StyleCophttp://stylecop.codeplex.com/
Ghostdoc http://submain.com/products/ghostdoc.aspx
Spellcheckerhttp://visualstudiogallery.msdn.microsoft.com/7c8341f1-ebac-40c8-92c2-476db8d523ce//
Lego (trademarked in capitals as LEGO)
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