debugging para el no iniciado

De Frustrado a CompetenteDebugging para el no iniciado:

Barcamp 2015, Santiago, R.D.

What we will cover


- What is debugging- Why is hard- Know yourself- The true path to debugging- The rules of debugging- What debugging displays- Remember

About me


Leonardo Jimenez (Un entusiasta del software)Blog: www.leonardo.docorreo: [email protected]

Co-Founder and Developer @CodetigerWe love Python, We use a ton of stuff

One of the organizers of @pythondo && @Jsdo

http://www.leonardo.do

mailto:[email protected]

Can you tell me what debugging means to you?

What is debugging?


What is debugging?


Can you tell me what debugging means to you?Some frequent answers:

- Make the error go away- Eliminate the errors on the screen- “Resolver…!”



What is debugging?


Most of the answers are related to fixing the actual problem ...

What is debugging?


My (really recent definition) Definition

“Debugging is the process of finding and resolving bugs or defects in the code in a manner that the code is better than the way it was found”

What is debugging?


Debugging Normally includes:

1. Get the bug in the database (if you are lucky)2. Reproduce the problem3. Automate and simplify the test case (if you know what you are doing)4. Find possible infection origins5. Focus on the most likely origins6. Isolate the infection chain7. Correct the defect

What is debugging?



1. Get the bug in the database (if you are lucky)2. Reproduce the problem3. Automate and simplify the test case (if you know what you are doing)4. Find possible infection origins5. Focus on the most likely origins6. Isolate the infection chain7. Correct the defect

{Understand the Problem

What is debugging?



1. Get the bug in the database (if you are lucky)2. Reproduce the problem3. Automate and simplify the test case (if you know what you are doing)4. Find possible infection origins5. Focus on the most likely origins6. Isolate the infection chain7. Correct the defect{

Search the Problem

What is debugging?




Fixing it

What is debugging?




Most of your time goes here

Why is debugging hard?


Key Takeaway #1Debugging is a problem of scarcity



Let’s do an exercise:- Search on Google “Learn to Program”



Let’s do an exercise:- Search on Google “Learn to Program”

- 1,540,000,000 Results (1.5 Billion results)



Let’s do another exercise:- Search on Google “Implement an

ordered List”

- 3,020,000 Results



Let’s do another exercise:- Search on Google “Ordered Hash Table”

- 758,000 Results



The more advanced your question is,the less easy answers you will find



Do you remember your first time?



Do you remember your first time?

print “Hello world”



Do you remember your first CRUD App?Your first blog?, your first to do list?

What do they have in common?



Do you remember your first CRUD App?Your first blog?, your first to do list?

What do they have in common?

You knew the whole App!!!



This is what it feels like working on a new, different and legacy codebase ...



The difference between a good developer and a bad developer is understanding.



The difference between a good developer and a bad developer is understanding.

Understanding of what does not change.

Know yourself


Do you understand the basics of your (Language/Library/framework) or you just did a tutorial?

Know yourself


Do you read the documentation while learning the technology or after something’s break?

Know yourself


Do you know the standard library well or you just copy/paste from stack overflow?

Know yourself


Know yourself (example)


def is_equal(a, b):return a is b

>> is_equal(2, 2)True>> is_equal(4, 3)False




>> value = 256>> is_equal(256, value)?




>> value = 256>> is_equal(256, value)True




>> value = 257>> is_equal(257, value)?




>> value = 257>> is_equal(257, value)False




Why???




Equality is different to Identity

In General


Key Takeaway #2The code can give you the right result for the wrong reasons.



Ruby Example



class Bicycle attr_reader :size, :parts

def initialize(args={}) @size = args[:size] @parts = args[:parts] end

def spares parts.spares endend



class Parts < Array def size parts.size endend



class Part attr_reader :name, :description, :needs_space

def initialize(args) @name = args[:name] @description = args[:description] @needs_spare = args.fetch(:needs_spare, true) endend



# Individual Partschain = Part.new(name: 'chain', description: '10-speed')road_tire = Part.new(name: 'tire_size', description: '23')tape = Part.new(name: 'tape_color', description: 'red')mountain_tire = Part.new(name: 'tire_size', description: '2.1')rear_shock = Part.new(name: 'rear_shock', description: 'Fox')front_shock = Part.new( name: 'front_shock', description: 'Manitou', needs_spare: false)



# Parts Objectsroad_bike_parts = Parts.new([chain, road_tire, tape])mountain_bike_parts = Parts.new([chain, mountain_tire, front_shock, rear_shock])



# Bicycle Objectsroad_bike = Bicycle.new(size: ‘L’, parts: road_bike_parts)mountain_bike = Bicycle.new(size: ‘L’, parts: mountain_bike_parts)



# Property Testsmountain_bike .size # - > ‘L’

mountain_bike.spares# - > [#<Part:0x00000101036770# @name="chain",# @description="10-speed",# @needs_spare=true>,# #<Part:0x0000010101b678# @name="tire_size",# etc ...



# Property Testscombo_parts =

(mountain_bike.parts + road_bike.parts)

combo_parts.size # - > 7

combo_parts.spares # - > NoMethodError: undefined method 'spares'# for #<Array:...>



# Property Testscombo_parts =

(mountain_bike.parts + road_bike.parts)

combo_parts.size # - > 7

combo_parts.spares # - > NoMethodError: undefined method 'spares'# for #<Array:...>

Why?

In General


The code can give you the right result for the wrong reasons.

The True Path to Debugging


In General


Key Takeaway #3Growing as a software developer means moving from memorisation to understanding

In General


Key Takeaway #4Avoid shotgun surgery become a neurosurgeon.



- Know Yourself tools - Search within your code- Be one with the universe person who asks



(You can Name it)

ARE

TOOLS



LEARN:- When to use it and when not- Learn Many and avoid a lot more- One really well- Learn the principles

In General


Key Takeaway #5Debugging is not a tool, is a mindset.

The mindset name is curiosity.

Be Curious.



READ THE $#%@$%# MANUAL:- Read the documentation- Read the specifications- Read the code (yes, for Fun)



If Nothing else works ask, but:

- Make sure you read the documentation- Make your homework- Tried to solve it yourself



When asking:

- Be respectful- Tell the facts not your theories- Don’t be proud

Debugging Rules


- Understand the system- Make it Fail- Quit Thinking and look- Divide and conquer- Change one thing at a time- Keep up an audit trail- Check if it is on- Talk with another person- If you don't fix it, it ain't fixed

Remember?


Do you remember the definition of Debugging?

What is debugging?


My (really recent definition) Definition

“Debugging is the process of finding and resolving bugs or defects in the code in a manner that the code is better than the way it was found”

Remember?


Does every interaction with your code making it better?

Remember?


Or do you sing ?

99 little bugs in the code99 little bugs in the code

Take one down, patch it around117 little bugs in the code

In General


Key Takeaway #6In order to be an amazing debugger you should be an incredible refactorer.

In the end- Don’t rush- Don’t Panic- Understand the problem - Understand your Language- Understand your tools- RTFM

In General


Preguntas??Debugging para el no iniciado:



Gracias !!

Blog: www.leonardo.docorreo: [email protected]: @leonardoajim


mailto:[email protected]

De Frustrado a CompetenteDebugging para el no iniciado:


debugging para el no iniciado

Software