Using templates for efficient mocks for testing arduino components....

mocktest.ino

#include <ArduinoUnit.h>

// This is pretty advanced, you need to use template specialization to
// create mocks with no runtime overhead (other than space to represent
// the mocked environment, if you choose to use it (probably in a test).

struct RealImpl {
  static void pMode(int pin, int mode) { pinMode(pin,mode); }
  static void dWrite(int pin, bool value) { digitalWrite(pin,value); }
  static int dRead(int pin)  { return digitalRead(pin); }
};

// You can have as many mock implementions as are useful
struct MockImpl {
  static void pMode(int pin, int mode) { /* ignore */ }
  static void dWrite(int pin, bool value) { /* whatever */ }
  static int dRead(int pin)  { return 0 /* whatever */; }
};

template <class impl> struct MotorTemplate {
  static void setup(int pin) {
     impl::pMode(pin,OUTPUT);
     impl::dWrite(pin,LOW);
  }
  // *other things */  
};

typedef MotorTemplate<RealImpl> Motor; // motor with real io

void useMotor() {
  Motor::setup(1);
  // ...
}

typedef MotorTemplate<MockImpl> MockMotor; // motor with mock io

test(motor) {
  MockMotor::setup(1);
  // ...
}

void setup() {

}

void loop() {
  Test::run();
}