Lean-Agile Acceptance Test-Driven Development Better Software Through Collaboration

Kenneth Pugh has over two-fifths of a century of software experience. Previously a principal at Pugh-Killeen Associates, he is now a fellow consultant for Net Objectives. He has developed software applications ranging from radar tracking to financial analysis. Responsibilities have included everything from gathering requirements to testing. After the start of the new millennium, he has worked with teams to create software more effectively with lean and agile processes. He has spoken at numerous national conferences; consulted and taught all over the world; and testified on technology topics. This is his seventh book. In 2006, his book Prefactoring won the Jolt Award [DrDobbs01]. In his spare time, he snowboards, windsurfs, and backpacks. Between 1997 and 2003, he completed the Appalachian Trail. The cover photograph of Mount Katahdin, the northern end of the trail, was taken by the author from Abol Bridge in Maine.

Introduction     1

Part I: The Tale

Chapter 1: Prologue     9

Ways to Develop Software     9

  One Way     9

  Another Way     9

  The Difference     10

The Importance of Acceptance Tests     10

System and Team Introduction     12

  The System     12

  The People     13

Summary     14

Chapter 2: Lean and Agile     15

The Triad and Its Units     15

Post-Implementation Tests     17

Quick Feedback Better Than Slow Feedback     18

Preimplementation Tests     19

Lean and Agile Principles     20

Summary     21

Chapter 3: Testing Strategy     23

Types of Tests     23

Where Tests Run     25

Test Facets     26

  Control and Observation Points     27

  New Test Is a New Requirement     27

Summary     28

Chapter 4: An Introductory Acceptance Test     29

A Sample Business Rule     29

Implementing the Acceptance Tests     31

  Test Script     32

  Test User Interface     33

  xUnit Test     34

  Automated Acceptance Test     35

  An Overall Test     36

Testing Process     37

Summary     37

Chapter 5: The Example Project     39

The Charter     39

  Objectives     40

  Project Acceptance Tests     41

High-Level Requirements     43

  Features     43

  Feature Acceptance Criteria     45

Summary     46

Chapter 6: The User Story Technique     47

Stories     47

  Features into Stories     48

  Roles     49

  Role Attributes     49

  Persona     50

  Stories for Roles     51

  Story Acceptance Criteria     52

  Acceptance Tests Determine Size     53

  Customer Terms     54

INVEST Criteria     55

Summary     56

Chapter 7: Collaborating on Scenarios     57

Use Cases from User Stories     57

  Simple Use Case     59

  Exceptions and Alternatives     60

  Acceptance Tests     63

  Documentation     63

Story Map     63

Conceptual Flow     65

Communication     66

Summary     68

Chapter 8: Test Anatomy     69

Triad Creates Tests     69

Test Context     70

Test Structure     71

  Calculation Table     73

  Data Table     74

  Action Table     75

Tests with Example Values     76

  Requirements Revised     77

  Acceptance Test Revised     78

Test with Values in Text     79

When and Where Tests Are Run     80

Summary     81

Chapter 9: Scenario Tests     83

Tests for Exception Scenarios     83

Tests for Business Rules     87

Cross-Story Issues     88

Don’t Automate Everything     89

Multi-Level Tests     90

User Interface Tests     93

Check the Objectives     93

Summary     94

Chapter 10: User Story Breakup     95

Acceptance Tests Help Break Up Stories     95

Business Rule Tests     96

A Story with a Business Rule     100

Summary     101

Chapter 11: System Boundary     103

External Interfaces     103

  More Details     107

External Interface Tests     108

  Component Tests     108

  Test Doubles and Mocks     111

What Is Real?     112

Story Map of Activities     113

Summary     114

Chapter 12: Development Review     115

The Rest of the Story     115

  Usability Testing     116

  Separating State from Display     116

  Quality Attribute Tests     118

  Workflow Tests     119

Deployment Plans     120

From Charter to Deliverable     120

Summary     121

Part II: Details

Chapter 13: Simplification by Separation     125

Complex Business Rules     125

  Simplify by Separating     126

  The Simplified Rule     128

Rental History     128

Summary     130

Chapter 14: Separate View from Model     131

Decouple the User Interface     131

Decoupling Simplifies Testing     136

Summary     136

Chapter 15: Events, Responses, and States     137

Events and an Event Table     137

States and State Transitions     139

Internal State or External Response     142

  Transient or Persistent States     144

  A Zen Question     144

Summary     144

Chapter 16: Developer Acceptance Tests     145

Component Acceptance Tests     145

  Field Display Tests     145

  Tabular Display Tests     147

Summary     151

Chapter 17: Decouple with Interfaces     153

Tests for a Service Provider     153

  The Interface     153

  Quality Attribute Tests     155

  Comparing Implementations     155

Separating User Interface from Service     157

  Separation of Concerns     158

Reusable Business Rules     158

Summary     159

Chapter 18: Entities and Relationships     161

Relationships     161

  Entities and Relationships     161

  Multiple Relationships     163

  Alternative Representations     166

Summary     166

Chapter 19: Triads for Large Systems     167

Large Systems     167

When a Customer Test May Not Be Required     169

  Data Conversion     170

  Database Conversions     170

What If There Are No Tests?     170

  Legacy Systems     172

Summary     173

Part III : General Issues

Chapter 20: Business Capabilities, Rules, and Value     177

Business Capabilities     177

Scenario Handling     178

Business Rules Exposed     179

A Different Business Value     179

Summary     181

Chapter 21: Test Presentation     183

Customer Understood Tables     183

Table Versus Text     185

Specifying Multiple Actions     185

Complex Data     187

Custom Table Forms     188

Summary     189

Chapter 22: Test Evaluation     191

Test Facets     191

  Understandable to Customers     191

  Spell Checked     192

  Idempotent     192

  Not Fragile     192

Test Sequence     193

  Workflow Tests     193

Test Conditions     194

  Separation of Concerns     194

  Test Failure     195

  Test Redundancy     196

No Implementation Issues     197

Points to Remember     197

Summary     198

Chapter 23: Using Tests for Other Things     199

Uses of Acceptance Tests     199

  Degree of Doneness     199

  Estimation Aid     200

  Breaking Down Stories     200

  Developer Stories     200

Tests as a Bug Report     201

  Root Cause Analysis     201

  Production Bugs     202

  Regression Testing     202

Summary     202

Chapter 24: Context and Domain Language     205

Ubiquitous Language     205

Two Domains     207

Summary     208

Chapter 25: Retrospective and Perspective     209

Recap     209

  The Process     210

  Testing Layers     210

  The Tests     211

  Communication     212

What’s the Block?     212

  Monad     212

  Unavailable Customer     213

  Change     213

  Risks     214

Benefits     214

Summary     215

Part IV Case Studies

Chapter 26: Case Study: Retirement Contributions     219

Context     219

The Main Course Test     220

  Setup     220

  Event     221

  Expected     221

  Implementation Issues     222

  Separation of Concerns     222

Business Value Tracking     223

One Exception     223

  Event     223

  Expected     224

Another Exception     225

  Event     225

  Expected     225

Two Simultaneous Exceptions     226

  Event     226

  Expected     227

The Big Picture     227

Event Table     228

State Transition Table     228

Summary     230

Chapter 27: Case Study: Signal Processing     231

It’s Too Loud     231

Sound Levels     231

Developer Tests     233

Summary     233

Chapter 28: Case Study: A Library Print Server     235

The Context     235

A Workflow Test     236

Summary     241

Chapter 29: Case Study: Highly Available Platform     243

Context for Switching Servers     243

Test for Switching Servers     244

Test for Technical Rule     246

Summary     248

Part V : Technical Topics

Chapter 30: How Does What You Do Fit with ATDD?     251

Test Platforms     251

Internal Design from Tests     252

Device Testing     254

Starting with User Interfaces     255

Black Box Testing     255

Unit Testing     256

Summary     256

Chapter 31: Test Setup     257

A Common Setup     257

Some Amelioration     259

Test Order     260

Persistent Storage Issues     260

Summary     261

Chapter 32: Case Study: E-Mail Addresses     263

Context     263

Breaking Down Tests     264

  Local-Part Validation     265

  Domain Tests     266

  Disallowed Domain Tests     268

  Test to Ensure Connection     269

  Verification Test     269

Summary     270

Part VI : Appendices

Appendix A: Other Issues     273

Context     273

Customer Examples     274

  Fuzzy Acceptance Tests     274

  Acceptance Test Detail     275

Requirements and Acceptance Tests     275

  Documenting Requirements and Tests     276

  Decoupling Requirements     276

  Separation of Issues     276

Testing Systems with Random Events     277

The Power of Three     277

Summary     278

Appendix B: Estimating Business Value     279

Business Value     279

Developer Stories     281

Summary     282

Appendix C: Test Framework Examples     283

The Examples     283

Fit Implementation     284

  Setup     284

  Check-Out CD     284

  Check-In     286

  Category-Based Rental Fees     287

Slim–Table Style     288

  Header     288

  Setup     288

  Check-Out CD     288

  Check-In     290

  Category-Based Rental Fees     291

Slim–Cucumber Style     291

  Setup     291

  Check-Out CD     292

  Check-In CD     292

  Scenario Library     292

  Category-Based Rental Fees     294

Robot     295

  Setup     295

  Check-Out CD     295

  Check-In CD     296

  Category-Based Rental Fees     296

Cucumber     296

  Check-Out CD     297

  Check-In CD     297

  Category-Based Rental Fees     297

Test Frameworks     298

Summary     298

Appendix D: Tables Everywhere     299

User Interface Tests with Tables     299

Requirement Tables     301

  Another Table     302

Quality Attribute Requirements     303

Data Tables     304

Summary     304

Appendix E: Money with ATDD     305

The Context     305

The Original Tests     306

The Acceptance Test Approach     307

Summary     310

Appendix F: Exercises     311

Calculator     311

  Create Some Tests     313

More Exercises     313

  Sam’s CD Rental     314

  Triangle     314

  File Copying Exercise     314

References     315

Epilogue     323

Index     333

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