Clean Code
Chapter 1: Clean Code
There Will Be Code
Bad Code
The Total Cost of Owning a Mess
The Grand Redesign in the Sky
Attitude
The Primal Conundrum
The Art of Clean Code?
What Is Clean Code?
Schools of Thought
We Are Authors
The Boy Scout Rule
Prequel and Principles
Conclusion
Bibliography
Chapter 2: Meaningful Names
Introduction
Use Intention-Revealing Names
Avoid Disinformation
Make Meaningful Distinctions
Use Pronounceable Names
Use Searchable Names
Avoid Encodings
Hungarian Notation
Member Prefixes
Interfaces and Implementations
Avoid Mental Mapping
Class Names
Method Names
Donโt Be Cute
Pick One Word per Concept
Donโt Pun
Use Solution Domain Names
Use Problem Domain Names
Add Meaningful Context
Donโt Add Gratuitous Context
Final Words
Chapter 3: Functions
Small!
Blocks and Indenting
Do One Thing
Sections within Functions
One Level of Abstraction per Function
Reading Code from Top to Bottom: The Stepdown Rule
Switch Statements
Use Descriptive Names
Function Arguments
Common Monadic Forms
Flag Arguments
Dyadic Functions
Triads
Argument Objects
Argument Lists
Verbs and Keywords
Have No Side Effects
Output Arguments
Command Query Separation
Prefer Exceptions to Returning Error Codes
Extract Try/Catch Blocks
Error Handling Is One Thing
The Error.java Dependency Magnet
Donโt Repeat Yourself
Structured Programming
How Do You Write Functions Like This?
Conclusion
SetupTeardownIncluder
Bibliography
Chapter 4: Comments
Comments Do Not Make Up for Bad Code
Explain Yourself in Code
Good Comments
Legal Comments
Informative Comments
Explanation of Intent
Clarification
Warning of Consequences
TODO Comments
Amplification
Javadocs in Public APIs
Bad Comments
Mumbling
Redundant Comments
Misleading Comments
Mandated Comments
Journal Comments
Noise Comments
Scary Noise
Donโt Use a Comment When You Can Use a Function or a Variable
Position Markers
Closing Brace Comments
Attributions and Bylines
Commented-Out Code
HTML Comments
Nonlocal Information
Too Much Information
Inobvious Connection
Function Headers
Javadocs in Nonpublic Code
Example
Bibliography
Chapter 5: Formatting
The Purpose of Formatting
Vertical Formatting
The Newspaper Metaphor
Vertical Openness Between Concepts
Vertical Density
Vertical Distance
Vertical Ordering
Horizontal Formatting
Horizontal Openness and Density
Horizontal Alignment
Indentation
Dummy Scopes
Team Rules
Uncle Bobโs Formatting Rules
Chapter 6: Objects and Data Structures
Data Abstraction
Data/Object Anti-Symmetry
The Law of Demeter
Train Wrecks
Hybrids
Hiding Structure
Data Transfer Objects
Active Record
Conclusion
Bibliography
Chapter 7: Error Handling
Use Exceptions Rather Than Return Codes
Write Your Try-Catch-Finally Statement First
Use Unchecked Exceptions
Provide Context with Exceptions
Define Exception Classes in Terms of a Callerโs Needs
Define the Normal Flow
Donโt Return Null
Donโt Pass Null
Conclusion
Bibliography
Chapter 8: Boundaries
Using Third-Party Code
Exploring and Learning Boundaries
Learning log4j
Learning Tests Are Better Than Free
Using Code That Does Not Yet Exist
Clean Boundaries
Bibliography
Chapter 9: Unit Tests
The Three Laws of TDD
Keeping Tests Clean
Tests Enable the -ilities
Clean Tests
Domain-Specific Testing Language
A Dual Standard
One Assert per Test
Single Concept per Test
F.I.R.S.T.
Conclusion
Bibliography
Chapter 10: Classes
Class Organization
Encapsulation
Classes Should Be Small!
The Single Responsibility Principle
Cohesion
Maintaining Cohesion Results in Many Small Classes
Organizing for Change
Isolating from Change
Bibliography
Chapter 11: Systems
How Would You Build a City?
Separate Constructing a System from Using It
Separation of Main
Factories
Dependency Injection
Scaling Up
Cross-Cutting Concerns
Java Proxies
Pure Java AOP Frameworks
AspectJ Aspects
Test Drive the System Architecture
Optimize Decision Making
Use Standards Wisely, When They Add Demonstrable Value
Systems Need Domain-Specific Languages
Conclusion
Bibliography
Chapter 12: Emergence
Getting Clean via Emergent Design
Simple Design Rule 1: Runs All the Tests
Simple Design Rules 2โ4: Refactoring
No Duplication
Expressive
Minimal Classes and Methods
Conclusion
Bibliography
Chapter 13: Concurrency
Why Concurrency?
Myths and Misconceptions
Challenges
Concurrency Defense Principles
Single Responsibility Principle
Corollary: Limit the Scope of Data
Corollary: Use Copies of Data
Corollary: Threads Should Be as Independent as Possible
Know Your Library
Thread-Safe Collections
Know Your Execution Models
Producer-Consumer
Readers-Writers
Dining Philosophers
Beware Dependencies Between Synchronized Methods
Keep Synchronized Sections Small
Writing Correct Shut-Down Code Is Hard
Testing Threaded Code
Treat Spurious Failures as Candidate Threading Issues
Get Your Nonthreaded Code Working First
Make Your Threaded Code Pluggable
Make Your Threaded Code Tunable
Run with More Threads Than Processors
Run on Different Platforms
Instrument Your Code to Try and Force Failures
Hand-Coded
Automated
Conclusion
Bibliography
Chapter 14: Successive Refinement
Args Implementation
How Did I Do This?
Args: The Rough Draft
So I Stopped
On Incrementalism
String Arguments
Conclusion
Chapter 15: JUnit Internals
The JUnit Framework
Conclusion
Chapter 16: Refactoring SerialDate
First, Make It Work
Then Make It Right
Conclusion
Bibliography
Chapter 17: Smells and Heuristics
Comments
C1: Inappropriate Information
C2: Obsolete Comment
C3: Redundant Comment
C4: Poorly Written Comment
C5: Commented-Out Code
Environment
E1: Build Requires More Than One Step
E2: Tests Require More Than One Step
Functions
F1: Too Many Arguments
F2: Output Arguments
F3: Flag Arguments
F4: Dead Function
General
G1: Multiple Languages in One Source File
G2: Obvious Behavior Is Unimplemented
G3: Incorrect Behavior at the Boundaries
G4: Overridden Safeties
G5: Duplication
G6: Code at Wrong Level of Abstraction
G7: Base Classes Depending on Their Derivatives
G8: Too Much Information
G9: Dead Code
G10: Vertical Separation
G11: Inconsistency
G12: Clutter
G13: Artificial Coupling
G14: Feature Envy
G15: Selector Arguments
G16: Obscured Intent
G17: Misplaced Responsibility
G18: Inappropriate Static
G19: Use Explanatory Variables
G20: Function Names Should Say What They Do
G21: Understand the Algorithm
G22: Make Logical Dependencies Physical
G23: Prefer Polymorphism to If/Else or Switch/Case
G24: Follow Standard Conventions
G25: Replace Magic Numbers with Named Constants
G26: Be Precise
G27: Structure over Convention
G28: Encapsulate Conditionals
G29: Avoid Negative Conditionals
G30: Functions Should Do One Thing
G31: Hidden Temporal Couplings
G32: Donโt Be Arbitrary
G33: Encapsulate Boundary Conditions
G34: Functions Should Descend Only One Level of Abstraction
G35: Keep Configurable Data at High Levels
G36: Avoid Transitive Navigation
Java
J1: Avoid Long Import Lists by Using Wildcards
J2: Donโt Inherit Constants
J3: Constants versus Enums
Names
N1: Choose Descriptive Names
N2: Choose Names at the Appropriate Level of Abstraction
N3: Use Standard Nomenclature Where Possible
N4: Unambiguous Names
N5: Use Long Names for Long Scopes
N6: Avoid Encodings
N7: Names Should Describe Side-Effects.
Tests
T1: Insufficient Tests
T2: Use a Coverage Tool!
T3: Donโt Skip Trivial Tests
T4: An Ignored Test Is a Question about an Ambiguity
T5: Test Boundary Conditions
T6: Exhaustively Test Near Bugs
T7: Patterns of Failure Are Revealing
T8: Test Coverage Patterns Can Be Revealing
T9: Tests Should Be Fast
Conclusion
Bibliography
Appendix A: Concurrency II
Client/Server Example
The Server
Adding Threading
Server Observations
Conclusion
Possible Paths of Execution
Number of Paths
Digging Deeper
Conclusion
Knowing Your Library
Executor Framework
Nonblocking Solutions
Nonthread-Safe Classes
Dependencies Between Methods Can Break Concurrent Code
Tolerate the Failure
Client-Based Locking
Server-Based Locking
Increasing Throughput
Single-Thread Calculation of Throughput
Multithread Calculation of Throughput
Deadlock
Mutual Exclusion
Lock & Wait
No Preemption
Circular Wait
Breaking Mutual Exclusion
Breaking Lock & Wait
Breaking Preemption
Breaking Circular Wait
Testing Multithreaded Code
Tool Support for Testing Thread-Based Code
Conclusion
Tutorial: Full Code Examples
Client/Server Nonthreaded
Client/Server Using Threads
Appendix B: org.jfree.date.SerialDate
Appendix C: Cross References of Heuristics
Epilogue
Index
Footnotes
The Clean Coder
Pre-Requisite Introduction
Chapter 1. Professionalism
Be Careful What You Ask For
Taking Responsibility
First, Do No Harm
Work Ethic
Bibliography
Chapter 2. Saying No
Adversarial Roles
High Stakes
Being a โTeam Playerโ
The Cost of Saying Yes
Code Impossible
Chapter 3. Saying Yes
A Language of Commitment
Learning How to Say โYesโ
Conclusion
Chapter 4. Coding
Preparedness
The Flow Zone
Writerโs Block
Debugging
Pacing Yourself
Being Late
Help
Bibliography
Chapter 5. Test Driven Development
The Jury Is In
The Three Laws of TDD
What TDD Is Not
Bibliography
Chapter 6. Practicing
Some Background on Practicing
The Coding Dojo
Broadening Your Experience
Conclusion
Bibliography
Chapter 7. Acceptance Testing
Communicating Requirements
Acceptance Tests
Conclusion
Chapter 8. Testing Strategies
QA Should Find Nothing
The Test Automation Pyramid
Conclusion
Bibliography
Chapter 9. Time Management
Meetings
Focus-Manna
Time Boxing and Tomatoes
Avoidance
Blind Alleys
Marshes, Bogs, Swamps, and Other Messes
Conclusion
Chapter 10. Estimation
What Is an Estimate?
PERT
Estimating Tasks
The Law of Large Numbers
Conclusion
Bibliography
Chapter 11. Pressure
Avoiding Pressure
Handling Pressure
Conclusion
Chapter 12. Collaboration
Programmers versus People
Cerebellums
Conclusion
Chapter 13. Teams and Projects
Does It Blend?
Conclusion
Bibliography
Chapter 14. Mentoring, Apprenticeship, and Craftsmanship
Degrees of Failure
Mentoring
Apprenticeship
Craftsmanship
Conclusion
Appendix A. Tooling
Tools
Source Code Control
IDE/Editor
Issue Tracking
Continuous Build
Unit Testing Tools
Component Testing Tools
Integration Testing Tools
UML/MDA
Conclusion
Index
Footnotes
Copyright
Title Page
Dedication
Contents
Chapter 1: โIโm thinkingโ โ Oh, but are you?
Chapter 2: Renegade perception
Chapter 3: The Pushbacker sting
Chapter 4: โCovidโ: The calculated catastrophe
Chapter 5: There is no โvirusโ
Chapter 6: Sequence of deceit
Chapter 7: War on your mind
Chapter 8: โReframingโ insanity
Chapter 9: We must have it? So what is it?
Chapter 10: Human 2.0
Chapter 11: Who controls the Cult?
Chapter 12: Escaping Wetiko
Postscript
Appendix: Cowan-Kaufman-Morell Statement on Virus Isolation
Bibliography
Index