Emergent Design [software development]

Cover......Page 1
Contents......Page 8
Series Foreword......Page 18
Preface......Page 24
Acknowledgments......Page 30
About the Author......Page 32
 How Long Have Human Beings Been Making Software?......Page 34
 What Sort of Activity Is Software Development?......Page 35
 What Is Missing?......Page 39
 Who Is Responsible?......Page 41
 Uniqueness......Page 42
 Patterns and Professionalism in Software Development......Page 44
 Andrea's Closet......Page 45
 Off to the Moon......Page 51
  Different Forces, Different Design......Page 55
  And There Are More Contextual Forces......Page 56
  The Costs and Benefits......Page 57
 The Value of Patterns......Page 59
 Summary......Page 60
Chapter 3 The Nature of Software Development......Page 62
 We Fail Too Much......Page 63
 Definitions of Success......Page 64
 The Standish Group......Page 65
 Doing the Wrong Things......Page 67
 Doing the Things Wrong......Page 68
 One Reason: The Civil Engineering Analogy......Page 71
 Giving Up Hope......Page 74
 Ignoring Your Mother......Page 75
 We Swim in an Ocean of Change......Page 76
 Accept Change......Page 77
 Embrace Change......Page 78
 Capitalize on Change......Page 79
 A Better Analogy: Evolving Systems......Page 82
 Summary......Page 85
Chapter 4 Evolution in Code: Stage 1......Page 88
 The Origins of Object Orientations and Patterns......Page 89
 An Example: Simple Conditionals and the Proxy Pattern......Page 91
 The Next Step: Either This or That......Page 95
 Why Bother?......Page 98
 One Among Many......Page 99
 Summary......Page 100
Chapter 5 Using and Discovering Patterns......Page 102
 Design from Context: More Carpentry from Scott......Page 103
 Patterns Help Give Us a Language for Discussing Design......Page 112
 Patterns in This Book......Page 113
 Summary......Page 114
 Elements of the Profession......Page 116
 A Visual Representation......Page 118
 Summary......Page 119
Chapter 7 Paying Attention to Qualities and Pathologies......Page 122
 Cohesion......Page 124
  Method Cohesion......Page 125
  Cohesion of Perspective Level......Page 127
  Class Cohesion......Page 129
  How Cohesive Is Cohesive Enough?......Page 131
  Intentional Coupling Versus Accidental Coupling......Page 132
  Types of Coupling......Page 134
 Redundancy......Page 139
  Redundancy and Coupling......Page 143
 Testability......Page 145
 Pathologies......Page 147
  Indicators of Weak Cohesion......Page 148
  Indicators of Accidental or Illogical Coupling......Page 149
  Indicators of Redundancy......Page 151
 Summary......Page 152
Chapter 8 Paying Attention to Principles and Wisdom......Page 154
  Fowler's Perspectives......Page 155
  Another Kind of Perspective......Page 156
  A Separate Perspective: Creation......Page 158
  Considering Construction Details Last......Page 160
 The Open-Closed Principle......Page 162
  Open-Closed at the Class Level......Page 164
  Open-Closed at the Method Level......Page 165
 The Dependency Inversion Principle......Page 166
 Advice from the Gang of Four......Page 168
  Designing to the Interface of a Method......Page 169
  Designing to the Interface of a Class......Page 171
  GoF: Favor Object Aggregation Over Class Inheritance......Page 172
 GoF: Consider What Should Be Variable in Your Design and Encapsulate the Concept That Varies......Page 176
 Summary......Page 179
Chapter 9 Paying Attention to Practices......Page 180
 Consistent Coding Style......Page 181
  Comments......Page 182
  Naming Classes, Methods, and Variables......Page 184
  Virtues of Coding Standards......Page 185
 Programming by Intention......Page 186
  Are They Really All Private?......Page 187
 Encapsulating the Constructor......Page 188
  Making the Decision......Page 192
 Commonality-Variability Analysis......Page 194
 Practices and Freedom......Page 199
 Summary......Page 200
 Economies of Testing......Page 202
  Unit Testing......Page 204
  Up-Front Testing......Page 206
 JUnit Framework......Page 208
  JUnit Basics......Page 209
  JUnit Examples......Page 211
  Rule.java: Code First, Then Test......Page 212
  RuleContainer.java: Test First, Then Code......Page 220
  Eliminating Redundancy: @Before and @After......Page 229
  Automating Tests in Batches......Page 232
  Exceptions and Unit Testing......Page 233
 Mock Objects......Page 237
  MockObject Frameworks......Page 239
  Faking It......Page 242
  Dependency Injection and the Endo-Testing Technique......Page 243
  Endo-Testing......Page 244
 Summary......Page 245
Chapter 11 Paying Attention to Disciplines: Refactoring......Page 246
 Refactoring Bad Code......Page 248
 Refactoring Good Code......Page 249
 Structural Changes Versus Functional Changes......Page 251
 Refactoring Helps You Choose Your Battles......Page 252
 Avoiding Refactoring: Prefactoring......Page 253
 The Mechanics of Refactoring......Page 254
 Refactoring Legacy Code......Page 264
 Summary......Page 266
 What Makes Development Test-Driven?......Page 268
  Test-Driven Versus Test-First......Page 269
  Designing from the Perspective of the Unit Test......Page 270
  Testing and Cohesion......Page 271
  Testing and Redundancy......Page 273
  The Strategy Pattern......Page 274
  Turtles All the Way Down......Page 275
  Mock Object/Mock Turtles......Page 276
 Mock Objects......Page 277
 Testing the Decorator Pattern......Page 281
 Summary......Page 286
 Making Decisions in an Evolving Design......Page 288
 Christopher Alexander and Forces......Page 289
  The Signal Processor Example......Page 290
  The PKZip Example......Page 295
  Testing and Forces......Page 298
 More Choices, More Forces......Page 299
 Summary......Page 304
 The Problem Domain: The MWave Corporation......Page 306
 The Teams......Page 308
 The Simplest Thing That Could Possibly Work......Page 310
 A New Requirement: Complex Machines......Page 314
 Oh, By the Way......Page 316
 More Good News......Page 318
 Summary: What a Long, Strange Trip It Has Been......Page 320
Chapter 15 A Conclusion: 2020......Page 322
Appendix A: Evolutionary Paths......Page 324
 Encapsulated Constructor to Singleton......Page 325
 Programming-by-Intention to Encapsulated Constructor to Strategy (Varying on an Issue Extrinsic to the Client)......Page 326
 Programming-by-Intention to Encapsulated Constructor to Strategy (Varying on an Issue Intrinsic to the Client)......Page 327
 Programming-by-Intention to Encapsulated Constructor to Chain of Responsibility (Varying on an Issue Extrinsic to the Client)......Page 328
 Programming-by-Intention to Encapsulated Constructor to Chain of Responsibility (Varying on an Issue Intrinsic to the Client)......Page 329
 Encapsulated Construction to Strategy to Singleton (Object Factory) to Adapter/Façade......Page 330
 Encapsulated Constructor to Proxy to Decorator with Singleton (Object Factory)......Page 332
Appendix B: Overview of Patterns Used in the Examples......Page 334
  Contextual Forces......Page 336
  Implementation Forces......Page 338
  Consequent Forces......Page 342
  Contextual Forces......Page 343
  Implementation Forces......Page 345
  Consequent Forces......Page 347
  Contextual Forces......Page 348
  Implementation Forces......Page 349
  Consequent Forces......Page 353
  Contextual Forces......Page 354
  Implementation Forces......Page 355
  Consequent Forces......Page 359
  Chain of Responsibility: The Poker Example......Page 360
  Contextual Forces......Page 362
  Implementation Forces......Page 365
  Consequent Forces......Page 369
  Contextual Forces......Page 370
  Implementation Forces......Page 372
  Consequent Forces......Page 378
  Contextual Forces......Page 379
  Implementation Forces......Page 381
  Consequent Forces......Page 389
  Contextual Forces......Page 391
  Implementation Forces......Page 393
  Consequent Forces......Page 395
  Contextual Forces......Page 397
  Implementation Forces......Page 398
  Consequent Forces......Page 403
  Contextual Forces......Page 404
  Implementation Forces......Page 406
  Consequent Forces......Page 409
  Contextual Forces......Page 410
  Implementation Forces......Page 412
  Consequent Forces......Page 416
 My View......Page 418
 An Alternate View......Page 422
Bibliography......Page 426
 A......Page 428
 C......Page 429
 E......Page 432
 F......Page 433
 H......Page 434
 L......Page 435
 M......Page 436
 P......Page 437
 R......Page 439
 S......Page 440
 T......Page 442
 W......Page 443
 Y–Z......Page 444