top 5 best ways to improve your code pyxis v2 - en

Top 5 best ways to improve your code

TOP 5 WAYS TO IMPROVE YOUR CODE

Write once read many.

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© Pyxis Technologies inc. Top 5 best ways to improve your code 3

Legacy code is code without testsMichael Feather in

Working effectively with legacy code

Without maintenance, code degrade rapidly

We must detect and get rid of code smell

INTRODUCTION


Reduce class

hierarchy

Prefer collaboration

Loose coupling

Increase cohesion

Une abstraction level per method

Layered architecture

Extract cut cittong concerns

MY 5 IMPROVEMENTS

1. Simplify conditionals

2. Remove comments

3. Clarify contracts

4. Control scope

5. Flush dead code


Reduce complexity Improve readability Improve maintainability Improve Reusability

SIMPLIFY CONDITIONALSWHY?

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There is more than one conditions (and / or)There is too many code in the bodyCondition is based on typeThere are nested conditionsThere are many outcome from the same information (if /

elseif / switch case)

SIMPLIFY CONDITIONALS WHEN?

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Refactor conditional statement Decompose conditional Consolidate conditional expression Consolidate duplicate conditional fragments Introduce null object Flatten nested if Don't use negative Keep conditional statement lean

Avoid conditional statement Replace conditional with polymorphism Replace conditional logic with strategy Replace conditional dispatcher with command

SIMPLIFY CONDITIONALSHOW?

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SIM

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IFY

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ITIO

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DECOMPOSE CONDITIONAL

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SIM

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IFY

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NA

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CONSOLIDATE CONDITIONAL EXPRESSION

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SIM

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IFY

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CONSOLIDATE DUPLICATE CONDITIONAL FRAGMENTS

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SIM

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INTRODUCE NULL OBJECT

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SIM

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FLATTEN NESTED IF

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SIM

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DON'T USE NEGATIVE

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As much as possible, try to use only one condition per if statement Use a method to combine many conditions

Inverse if statement if most of the code is inside the true branch Avoid double negation

SIM

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KEEP CONDITIONAL STATEMENT LEAN

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SIM

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REPLACE CONDITIONAL WITH POLYMORPHISM

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SIM

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REPLACE CONDITIONAL LOGIC WITH STRATEGY

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SIM

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REPLACE CONDITIONAL DISPATCHER WITH COMMAND

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Improve readability Improve maintainabilityAvoid obsolete comments

REMOVE COMMENTSWHY?

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Each time a comment add anything else than useful information, intention, clarification, warning, todo or amplification

Comment for empty block of code Empty catch

Describe code line by line Example:

// Getting connection string from configuration // Opening connection // Retrieving data // Closing connection

REMOVE COMMENTSWHEN?

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Replace comment with good naming Extract method Use meaningful words

Write useful commentsRespect standard naming (MSDN: Guidelines for names)

Properties Enums Events Methods

REMOVE COMMENTSHOW?

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http://msdn.microsoft.com/en-us/library/ms229002.aspx


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EXTRACT METHOD

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Use Intention-Revealing names d elapsedInDays

Avoid disinformation AccountList Accounts

Make meaningful distinction moneyAmount vs money vs amount InvoiceTotal

Use pronounceable names genymdhms generationTimestamp

Avoid mental mapping a account

Class names noun not verbs Method names verbs Don't be cute. Use standard names

Destroy, kill, obliterate Delete Solution Domain Names vs Problem Domain Names

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USE MEANINGFUL NAMES

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Use PascalCase namingUse noun or adjectiveDon't use names that might be confused with a

Get Prefix boolean with Can, Is, or Has

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PROPERTIES

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First element should be default value

Use PascalCasing namingSingle value enum should

be singularBit field enum should be

plural and has a Flag attribute

Bit field enum values must be coherent (Read & Write == ReadWrite)

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ENUMS

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Use PascalCase namingUse past to describe post-event and present

progressive for pre-eventProvide a virtual methodProvide a cancel behavior for a pre-event

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EVENTS

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EVENTS

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Use verbs as method name ProcessPayment

Explicitly express return type in method name CreateCustomer GetInvoice

Use coherent naming (Get, Fetch or Retrieve but not all for the same usage context)

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METHODS

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Improve performance Improve readability Improve reusability

CLARIFY CONTRACTSWHY?

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The is too many paramters (how many is too much?)A method has more than one responsabilityA method use out paramters

Except for: TryPattern Service contracts

You need a default value

CLARIFY CONTRACTSQUAND?

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Reduce the number of paramters Introduce parameter object Create overload with less parameters Use default value

Outputs Use complex return type Use out parameters only when necessary

Maintain parameters order for overloads

CLARIFY CONTRACTS HOW?

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CL

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NT

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SINTRODUCE PARAMETER OBJECT

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CL

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SCREATE OVERLOAD WITH FEWER

PARAMETERS

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CL

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SUSE DEFAULT VALUE

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Avoid side effects Improve reusability Improve maintainability

CONTROL SCOPEWHY?

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A field is used only n a few methods Internal implementation is exposed by public members

CONTROL SCOPE WHEN?

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Visibility protected private internal

Responsibility Move a field inside a method Split class Move variable closer to usage

Lifetime Create instances as needed Release reference as early as possible

CONTROL SCOPEHOW?

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Because we must Improve maintainability Improve performance Improve readability100% test coverage

FLUSH DEAD CODEWHY?

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You know the code is deadYou think the code is deadYou want the code to be dead

FLUSH DEAD CODE WHEN?

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Identify and remove the code Delete le code Compile Run unit tests

What is dead code? Code in comments Code not covered by unit test

Tools There are tools that delete any line of not covered by at least one

unit test

FLUSH DEAD CODE HOW?

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Refactoring – Improving the design of exist ing code Auteur: Martin Fowler Edition: Addison Wesley ISBN: 978-0-201-48567-7

Refactoring to patterns (Mart in Fowler signature) Auteur: Joshua Kerievsky Edition: Adison Wesley ISBN: 978-0-321-21335-1

Clean code – a handbook of agi le software craftsmanship Auteur: Robert C. Martin Edition: Prentice Hall ISBN: 978-0-132-35088-4

Working effect ively with legacy code Auteur: Michael C. Feather Edition: Prentice Hall ISBN: 978-0-13-117705-5

REFERENCES


Questions?Remember

Eric De Carufel [email protected] http://blog.decarufel.net

THE END

Simplifyconditiona

ls

Remove comments

Control scope

Clarify contracts

Flush dead code

mailto:[email protected]

http://blog.decarufel.net/

top 5 best ways to improve your code pyxis v2 - en

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