Test Driven Development for Embedded C

Contents......Page 8
Foreword by Jack Ganssle......Page 13
Foreword by Robert C. Martin......Page 15
Acknowledgments......Page 18
Preface......Page 20
How to Read This Book......Page 21
The Code in This Book......Page 22
Online Resources......Page 23
Test-Driven Development......Page 24
Why Do We Need TDD?......Page 25
What Is Test-Driven Development?......Page 27
Physics of TDD......Page 28
The TDD Microcycle......Page 29
TDD Benefits......Page 32
Benefits for Embedded......Page 33
Getting Started......Page 35
What Is a Unit Test Harness?......Page 36
Unity: A C-Only Test Harness......Page 38
CppUTest: A C++ Unit Test Harness......Page 44
Unit Tests Can Crash......Page 48
Where Are We?......Page 49
Elements of a Testable C Module......Page 51
What Does an LED Driver Do?......Page 53
Write a Test List......Page 54
Writing the First Test......Page 55
Test-Drive the Interface Before the Internals......Page 61
Incremental Progress......Page 68
Test-Driven Developer State Machine......Page 70
Where Are We?......Page 72
Grow the Solution from Simple Beginnings......Page 75
Keep the Code Clean---Refactor as You Go......Page 91
Repeat Until Done......Page 94
Where Are We?......Page 101
The Target Hardware Bottleneck......Page 104
Benefits of Dual-Targeting......Page 106
Risks of Dual-Target Testing......Page 107
The Embedded TDD Cycle......Page 108
Dual-Target Incompatibilities......Page 111
Testing with Hardware......Page 116
Where Are We?......Page 120
We Don\'t Have Time......Page 122
Why Not Write Tests After the Code?......Page 126
Unit Tests Don\'t Find All the Bugs......Page 127
We Have Existing Code......Page 128
We Have Constrained Memory......Page 129
We Have to Interact with Hardware......Page 130
Why a C++ Test Harness for Testing C?......Page 131
Where Are We?......Page 132
Testing Modules with Collaborators......Page 133
Collaborators......Page 134
Breaking Dependencies......Page 135
When to Use a Test Double......Page 139
Faking It in C, What\'s Next......Page 140
Where Are We?......Page 144
Spying on the Production Code......Page 145
Dependencies on Hardware and OS......Page 147
Link-Time Substitution......Page 148
Spying on the Code Under Test......Page 149
Controlling the Clock......Page 154
Make It Work for None, Then One......Page 155
Make It Work for Many......Page 170
Where Are We?......Page 175
Testing Randomness......Page 177
Faking with a Function Pointer......Page 179
Surgically Inserted Spy......Page 182
Verifying Output with a Spy......Page 186
Where Are We?......Page 191
The Mock Object......Page 193
Flash Driver......Page 194
MockIO......Page 202
Test-Driving the Driver......Page 205
Simulating a Device Timeout......Page 208
Is It Worth It?......Page 211
Mocking with CppUMock......Page 212
Generating Mocks......Page 214
Where Are We?......Page 216
Design and Continuous Improvement......Page 218
SOLID, Flexible, and Testable Designs......Page 219
SOLID Design Principles......Page 220
SOLID C Design Models......Page 223
Evolving Requirements and a Problem Design......Page 226
Improving the Design with Dynamic Interface......Page 233
More Flexibility with Per-Type Dynamic Interface......Page 242
How Much Design Is Enough?......Page 246
Where Are We?......Page 247
Two Values of Software......Page 249
Three Critical Skills......Page 250
Code Smells and How to Improve Them......Page 252
Transforming the Code......Page 263
But What About Performance and Size?......Page 281
Where Are We?......Page 284
Adding Tests to Legacy Code......Page 285
Boy Scout Principle......Page 286
Legacy Change Algorithm......Page 287
Test Points......Page 289
Two-Stage struct Initialization......Page 292
Crash to Pass......Page 296
Characterization Tests......Page 301
Learning Tests for Third-Party Code......Page 305
Test-Driven Bug Fixes......Page 307
Where Are We?......Page 308
Ramble-on Test Antipattern......Page 310
Copy-Paste-Tweak-Repeat Antipattern......Page 312
Sore Thumb Test Cases Antipattern......Page 313
Duplication Between Test Groups Antipattern......Page 0
Behavior-Driven Development Test Pattern......Page 316
Where Are We?......Page 317
Closing Thoughts......Page 318
Appendixes......Page 321
Development System Tool Chain......Page 322
Full Test Build makefile......Page 324
Smaller Test Builds......Page 325
Unity Test File......Page 327
Unity TEST Condition Checks......Page 329
Unity in Your Target......Page 330
The CppUTest Test File......Page 332
TEST Condition Checks......Page 333
Scripts to Create Starter Files......Page 334
Convert CppUTest Tests to Unity......Page 336
LedDriver First Few Tests in Unity......Page 337
LedDriver First Few Tests in CppUTest......Page 338
LedDriver Skeletal Implementation......Page 339
Example OS Isolation Layer......Page 340
Test Cases to Assure Substitutable Behavior......Page 341
POSIX Implementation......Page 342
Micrium RTOS Implementation......Page 344
Win32 Implementation......Page 346
Burden the Layer, Not the Application......Page 348
Bibliography......Page 349
D......Page 352
I......Page 353
Q......Page 354
T......Page 355
Z......Page 356